I spent a major part of my teenage years scavenging junkyards for these heads. Everyone that had a SBC in the 70s and early 80s just had to have a set. I would do the backyard port work, install the "LT1 Carrrviiitte" springs, guide plates, and studs, and had them sold as fast as I could find and build them. Those heads hold a special place in my heart.
Did the same .My father was the shop mgr at a large gm dealer i got all the engines they swapped out with new 350 & 454 4 bolt blocks.heads etc! I had full run of the machine shop I sold alot of engine parts to buy parts for my drag cars!
I grew up in the hood, and we had awesome boneyards back from 19 whenever, till about 1986- There were goodies everywhere if you were persistent and sly😎😂🤙🏼
As an old timer thanks for sharing some stuff my Era. That's all I used to do just a little bowl work and port match. Still got few pairs 461,462 , set of my favorites 3927186 with accessorie holes. Other than the weight of iron. They work just fine. Gotta love old iron
I still use these and 186s on SBC builds to this day. I started building motors in the 70s and these were THE GO TO THING. One JUST went out the door with 186s and all the goodies. They are harder and harder to find and the aluminum head market has become more affordable in recent years. ❤
The camel humps were still the hot ticket when I was a teenager in the 80s. Those heads, a 70s junkyard truck 400 bored out to 406, 280 cam, 3500 stall, 4.10s, ladder bars, in something light like a Chevy II or Nova, you could run in the 12s for not too expensive if you had your stuff dialed in. On a side note, the infamous Penske TA race prepped Z/28 cars of the late 60s made 480 HP with 302ci with a cross ram and these heads, ported to Traco's specs. Dual 780 Holleys, pretty radical cam timing I'm sure, but anyway. Nowadays, I would by the Trick Flow aluminum reproductions of these, they have modern combustion chamber design and will make more power. But these are still super cool for the history involved with them.
so true man.....seen a many 400 stock bottom end with double humps 280 cam hedders take down a many street car man......back before Big money got involved.
My brother and I built a V8 Vega in 1978, and we specifically went looking for an engine with camel hump heads. We found a 275HP 327 4-barrel in a 1968 station wagon that had the camel humps. 1.94" intake, 1.50" exhaust. I think there were also 461 or 462 heads that had 2.02/1.60 valves on the higher power 327, 350, and DZ 302's. 292 (turbo) heads were never sold on production line cars, but they were the ultimate sbc head through the 70's. Then Chevy introduced Bow Tie heads around 1980, in either cast iron or aluminum. Yeah, I'm old.
The 462's had the 1.94" intake valve instead of the 2.02" version,,at least the 462's I had..same nice combustion chambers..I had several of the 461 and 462's..great heads.
Yep... there were several variant of heads cast with "double hump". You'd be surprised how many people think the casting mark alone means "Corvette/Impala 327 fuelie 375hp". It doesn't.
Interesting, I have 2 sets of ported 461 heads, 461 64cc chambers and 461X 58cc, the 461X heads were used in Pro Stock and are thicker steel around each chamber so you don’t break through to water. Always knew they flowed well for a cast iron head. Use 215’s and 58cc heads these days running 12.5:1 comp. Well over 600HP out of 383 cubes.
those 461x,s was the hot ticket....i,m 50...but back in the day they truly made a diff. when there was people that said different.....those were the true high horse small journal double heads from early 60,s till mid 60,s
My 461x heads had the smaller valve set not 2.02 ?? ; took them to Darrell Buell machine shop for hard seats and they broke-thru to the water jackets-- instant junk.
When I was a senior in high school, mid 80's, in my advanced auto class my auto teacher drew me a picture of the "camel back" head because I was looking for small block to build. I found several SBC in a van inside there was a 283 with "power pack" heads, a 350 with who knows what, then there was the buried motor and it had the holy grail heads on them! Bought it for $150. The motor was a 327 and I thought I was the man when unloading this in the auto shop. Wound up rebuilding them by knurling the guides, 3 angle valve job on the seats, back cutting the valves, shimming the stock springs, then cutting the guides for what we called PC valve seals (the type used today). Bought a Crane cam, Clevite 77 bearings, Victor gasket set, Melling's high volume oil pump, Holley aluminum intake and carburetor. Talk about thinking you were Mr. Hot Rod magazine at 17 years old. It's kind of a bummer that searching/scrounging then putting it all together with your brain and skill for a working combination are sort of disappearing today, t's whoever spends the most money is the coolest now. Another great video.
It was my HS shop teacher that taught me about them also! I always thought up to that point if you put enough cam in something it'd run good. He said you had to get some of these heads and machine them out for 2.02 valves. How right he was!
Was your teacher Mr Jimmy Peterson ? Sounds like my Power Mechanics and auto tech teacher in 1980-1982..he loved when I took my friends 69' 0r 70' SS El Camino with the factory 396 in it..the best days of my life !
An NHRA Superstock 327/275 with double humps, stock port volumes (165 int/65 exh) (epoxied int, welded exh) 1.94" int 1.50 exh , flat top piston, an intake that has to fit under the stock hood and a QJet make, (an average one (mine),will make 560 hp @ 7400.
@@tenthousanddays2103 Remember the old stick shift 57 Chevy 283 National record holder? In 86-87' My since past machinist bought it for a 283 upgraded but never built it back again.
I turned 16 in 1984 and double humps were the best we had as a teenager. My stepdad helped me port a set of 186 heads for a flat top 350. He did a 3 angle valve job and picked out a camshaft for me. If I remember correctly it was the 327/350hp specs ground on a 108 lobe center. It ran really well in my 1967 Camaro.
David Vizard has a great video up thats really good, step by step porting tech on the double hunps. He gets about 270 intake flow, enjoy ur channel Eric
I built a 327 and ported a set of 194 camel humps using his book as a guide. Lots of careful porting, awesome engine. They dont call him Vizard the wizard for nothing, the man knows his chevy small block performance.
Started running a small fleet of c30 type trucks and a few strip and off-road vehicles in 1980. Cooling the heads was not a bad idea. Greatly helps with engine longevity.. The cross over exhaust port was to help with our cold county engine warm up as well as engine longevity. Still running a couple of those C30's and the 450hp to the ground SBC in a Landcruiser . It's not just the power you need. It's keeping it up and running for years (and miles) that matters.
Great content Eric. Thanks for sharing. I built alot of these heads back in the day. 461 and 462. Great cylinder heads for what there were. Take care, Ed.
Thanks Eric, As a long time sbc fan who cringes every time I hear Ls swap it I'm glad to hear honest critique that doesn't just run the old sbc into the ground and discount their performance capability
LS swappers litterly tell the world that they are not hot rodders. Just bolt on parts is what that world is about and they are like sheep just going with the herd. Vintage iron requires actuall grinding bending and massaging of parts to make everything optimized and perform in sinc. That's hot rodding. That's a true gear head.
@@shootermcgavin2819 lol that's a little harsh, but funny. What the LS does make super easy is port fuel injection, with the factory computer and HP Tuners. And the factory heads and manifolds flow pretty well right out of the gates. A garden variety junkyard 5.3 with no mechanical issues and a Truck Norris cam will make an honest 415 HP gross if you are a good tuner or have a good tuner. That's pretty attractive to a lot of people. I personally prefer the nostalgia of the SBC, but I can understand wanting decent power without too much fuss.
@Jim Bronson The Holley Sniper two is here. It all plug and play with any engine or transmission. The dash can be incorporated or you can stand alone literally on Android wifi now. The dreams if the 1990s street and strip are here for mix and match. Old school SBC prior to the 90s with good bottom ends will now shine and piss off a ton of LS power plants in any trim. 350 HD truck blocks with old ported heads and a built 4L60E stall speed and hold beer 😆 wheels up fun! Today's rings, pistons, and induction with ignition control was really about all they ever needed. You can tell it what to do not what it was asking for 😉 They ran near 800hp blown pump gas on the street back then. Now it's turbos and boost controllers so what is it's limits?
I just built a 66 327 Chevy II block with a set of 291's no porting and the final compression ratio was 11.1 to 1, also with a Crane Cam version of the Duntov 30/30 solid lifter that a guy had in his garage for 30 years and made 407 HP on the engine dyno
Eric.. you left out the Chevy 292 Turbo heads.. Made famous by Bill Grumpy Jenkins.. you could by them at any Chevy dealership.. They had screw in studs, 2.02 intake and 1.6 ex value and they were 180 cc. Also they were angle plugs. They're were the best.cast iron heads back in the day.. keep up the good work
461X heads had the big intake ports also. As to how good vortec heads are in the 90s we had a costumers 2barrel motor lost a whole point in compression and was still up over 20 hp on a 1.94 vortec. 2.02 valves just hurt flow on them.
Double Humps were so hot back in the 60s and 70s when I was driving Tri-5s and still had money . Building small blocks that screamed and aggravated everyone in our neighborhood . Choppy idle and sounded mean as Hell . oh back in the day . Awesome video .
I have seen 377 SBC with double hump heads made 480 HP to the wheels that in a street car. 10.5:1 compression 107 lsa flat tappet cam shaft and a 750 Holley double pumper carburetor. Rear Gear ratio 3:73
The l98 flows a bit less but they had other advantages. The valves were a touch smaller (though some camel humps on budget engines had pressed rocker studs and the 1.940/1.500" valves) but the chambers were small enough for small engines and would give compression to a dished piston 350 as well.
@@robertwest3093 Lingenfelter was getting 260-270 cfm out of the 113s back in the early 90s with excellent port velocity. I had a pair on a 305 with a XFI 276 cam that made 423 hp @ 6,400 rpm using a single plane intake and GM 2" bore 454 TBI unit.
If I remember the center small port in the head was not for smog , it was used to heat up the intake to help warm up the carb ,to stop cold morning stumble ,hesitation on take off . More for colder climate states . We always used block off intake gaskets for racing . great video to enlighten all the new young guys about the past.
Taking your comment one step further, they also used a heat riser in one exhaust manifold that had a weight and a spring on it. When the engine was cold, idling, the heat riser restricted exhaust flow, which caused the exhaust to pass through the runner under the carb, and out the other exhaust. When the heat riser spring warmed up, it relaxed and allowed the exhaust to exit unrestricted, reducing the exhaust flow under the card.
It typically comes back to emissions. Engines make many times more emissions on warm up. So the quicker they can get the incoming air warm and choke off the less emissions they make every cold start. The choke works well enough that it shouldn’t stumble cold. If it does you may need a couple sizes larger primary jets.
@@ztwntyn8 Hate to disagree , Spent a lot of time diagnosing ,carb problems back in the 70s 80s 90s for Drivability complaints , most cold morning start up problems was choke not set right . Timing off , vacuum hose's split ,heat stove pipe missing exhaust choke valve spring stuck ,and of course accelerator pump not working . So as to your possible fix to replace jet size , that was never done ,by me or any other tech . We change jets in carbs mainly for drag racing purposes , in the 2000s to today emissions got way better due to higher compression , better timing and fuel control So after 47 years as a mechanic ,learning everything from points to sliding cam shafts I would say changing jets ,would not be the correct way . 30years GM tech -17yr city fleet tech . My 2 cents
There's also the 461X heads, which was even better than your standard 461, but they are rare! They were the true holy grail back in the day, but they got sewer size ports.
There was also the GM sbc (370) castings which were a fully closed chamber head but with accessory holes drilled for long waterpump stuff. For that reason. I always tried for those if when I could get them. They port up well and were a great alternative.
From the numbers I've seen, all but the 186 double humps should flow enough at 0.500 lift in stock form to make 400 horsepower. The LS guys do have a point though. They can do it with less compression and a more street friendly cam. For example, even the early 2.00/1.55 valved LS-1 806 heads flow a bit more at 0.400 than 461 DH's with 2.02/1.60 valves do at 0.500 and the '97 LS-1 made 345 net HP with a kitten like idle. That said, I still think it's blasphemy to swap an LS into a classic.
Old 300 Horse 327 Cubic Inch Heads... even found in late sixties 4 door grocery gettin Impala's and Wagons. Porting, Static Compression and the Right Cam... they set a couple of National Records back in the day with a few tricks on the side. One of the long-term engine builders in my area told me they converted them to angle plug heads to aid in part flame travel across the dome. (suspect dome mass had a part in moving the plug too)
I’ve watched this video like 3 times now, the double humps we’re getting phased out in mid 90’s when I began, still cool though and respect them as well as their legacy. I’d like to send you some big block Olds heads to flow, they were cut for the “big” BBO valves, minor blend (like these 491’s), the AIR bumps in the exhaust runners smoothed and intake valves were back cut.
I always say, "the worse the engineer, the better my friend". I make my living from fixing problems that others can't, and at least 80% of my work is the direct result of bad engineering. It sounds like you and I will never be friends 😂😂😂
The double hump heads with the accessory holes were casting number 186. There were also an early seventies head that didn’t have the double humps that also had accessory holes that were performance factory castings with the 64 cc chambers that were casting number 041. I have a pair of those. Chevy also made casting number 292 heads that were angle plugs but were never offered on a factory car. They were off-road use only and were also the version that many of the aftermarket heads afterwards were designed from.
We angle milled those camel humpers so far that we had to plug the cooling holes for the spark plugs. So much work was involved to do that to correct the head geometry but that`s what happens in spec circle track racing
I have a old pair of 1968 041s off a 1970s Modified Production class engine that flow 270+cfm. Car ran mid 10s with them. They are hogged out to the point that they pretty thin, id be afraid to use them on the street. Plus theyve been milled alot. Intake valves hang lower than the deck.
The factory used an unshrouding tool on a drill press for all SB. 202 ,160 valves. A 40 thousands up to 69 and than a 35 up to 1980 .because if you didn't they flowed worse than the 196/ 150
aweshome. Hey this is crazy i am really know it, although tell me what you think if it would run ok until i make this 355 a 396. Brodix IK 210cc heads. Ok on a 355 with 11:1 compression and ported RPM non air gap or?, and XR300HR cam or smaller on 106^ LSA and ICL. 3200 lbs. street camaro 2nd gen. No pwr steering. No pwr brakes. just alternator and waterpump. Want to disguise it gm corporate blue with 305 valve covers. 3.73 gears. BFG tires.
Back in 1974, i was building lots of sbc engines. It wasn't too hard to get 350hp out of a 350. And have it very streetable. I built both the straight and angle plug heads. I found that the 194 straight plug heads were better for street use unless you had a reason to wind your motor over 6200+. Who does that? Only if your rich. (Not me) And we had the problem with octane going down. Now the 202 angle plug heads were great for serious street use and racing. But i had problems with drivability and plug fouling if the motor wasn't tuned perfectly every time. Excellent review. Takes me back to the good old days when building the sbc was simple, fun, and somewhat cheap.
I had a bad experience back in the day with the 461 head and specifically the 461X which purportedly was an extra hi-flow 461 but for some reason had the smaller valve set ? So back in the early ’60s bought a 327/340hp out of a totaled 1962 Corvette. Put this engine in my ’32 roadster with a T-10 and it was a screamer. When leaded fuels left us, send the heads over to an engine machinist for hard seats. Well, said machinist later calls me with the “news” that he went into the water jacket on both heads (why not stop at the first head ?); apparently the “X” meant very thin castings to get more flow ? In retrospect, in a light 2400lb car which would never see heavy loads, I should have left the heads alone instead of doing the “right thing” and ending up with two boat anchors.
186 double humps started in 69. Basically the exact same head as the 461 with same 64cc chamber but with accessory holes. Commonly seen on the 302 DZ engine, 350-300hp and the LT-1 350-370hp. The higher HP versions with 2.02/1.60 valves. Hope that helps. One of these days Eric I'd love to see you review the Trick Flow version of these hump heads. They reproduce an aluminum version for those of us that like stealthy, but are enhanced a bit with modern chambers, larger runners etc... I've been meaning to order a set for a build I've had on the back burner.
@@Levisnteeshirt1 They were 64cc. In fact the factory 2.02 valve version is easy to tell as they actually had a machined relief in the chamber for the valve from the factory. The 1.94 version didn't have that.
Wrong. Intake heat was for fuel atomization. It is also why you look into the plenum of a factory intake and see ribs at the bottom. It was for converting the fuel droplets into vapor. That is also why many older engines would run a little rough at start up and then start running smooth after a minute or so. The vaporized fuel distributes more evenly.
@@beestoe993 100% the heat crossover is used to keep the carburetor for icing up this is common knowledge isn’t even a controversial comment not even a little bit, I’m sure efficiency may have been a byproduct as well but the main reason was to keep the throttle blades from icing up
I just picked up a little hopped up h.o. 305 that the guy built a 335 stroker with and it has the 462 DH heads and i am plucking them off it to toss on my 383 as i have bought 4 sets of vortec heads and there has been cracks in 7 of the 8 heads, i am done spending money on the thin poorly made vortec heads, i think these little 462s will do me just fine with my flat top 10-1 pistons with the steel shim gaskets i should be right at 10.5-1 so i should still be good on pump gas, can't wait to go from the 76cc heads with .046 gaskets to the 64 cc and .015 gaskets to see what kind of difference there is, the heads have had a slight clean up done to them and gasket matched, nothing to big but should do ok, i hope! :)
I built back in 2000 a 383 with 461's Making about 450 HP The car is a 1980 Firebird I run at Gainesville, FL. 1/8 mile 7.55 and 11.7 1/4 mile. 461's are good Heads. !!! PS. 110 VP Gas 13 to 1 compression.
There are 2 heads that were the same as a double hump but didn't have the double hump markings..040 with no bolt holes and 041 with the bolt holes.people passed them up because they didn't have the humps
I had a set of 492s on a 350 I built back in 1993. They were not angle plug heads, and they were 1.94/1.5 but they were still good for 300 HP on a 1988 Caprice. The 492s were available either as straight or angle plugs. The 492s also had the accessory drive bolt bosses/holes drilled in them where the earlier heads, like these 461s, did not. There were also 462 heads that were of this vintage and the difference was the 461 was a 'closed chamber' head and the 462 is an 'open chamber' head. The 492 is the same as a 462 but with those bolt holes in the ends. Also, the extended water jacket allowed them to get more compression on pump fuel at the time, these were 30 years before the 'reverse flow' SBC Gen 2 engines came out (the LT1/LT4). The exhaust port in the middle of the intake side is for a 'heat stove' under the intake plenum, which facilitates faster engine warm up times by allowing the heat to better vaporize the fuel coming out of the carb. It's not for emissions, it's for driveability.
292x casting head I believe we're done in two versions, of course angle plug, one had 185 cc intake, the other 200cc, I always thought Ole Smokey had a key to all manufacture back door, smokey influenced the 200cc intake, they are one cover of his book
This is off the top of my head. 461’s were the “Fuelie head”, in -65 they had the 461X, that was the 375 HP 327 Rochester Injected Vette. 292 was a mid -70’s Chevy Performance head, I remember them being referred to as “Turbo heads”, not that there was any turbocharging in the picture. Then in the late -70’s / early -80’s, is when the “Bow Tie” parts came into being.
@@No1414body Eric said 086 were dbl hump with accessory holes but it’s 186’s not 086. I got a OTC 68 327 CE block with 186’s screw in studs and guide plates. People said they ask for a Corvette 327 at the parts counter when they bought it heads are dated 12/68.
I grew up hearing about them double hump heads old timers be arguing who’s is better lmao 🤣 in the south the arguments about heads get weird on guy said he’s where so good they was triple hump heads
The big disadvantage to vortec heads is that 80%of them are cracked and the rest will eventually crack! The early chevy heads(pre amog) rarely cracked unless you were doing something really extreme.
Thanks very much for that great video.... I've just put a set of 461s on a 350 I've put together at home for a mild jetboat motor.. Cam intake exhaust flat top pistons etc... Every one said go LS... Out here in New Zealand but I don't have the money for LS... It certainly makes me feel better now that I'm on the right track with making some old school power... Hopefully it makes at least 300hp😬 most guys were saying you'll be lucky to get 250hp...don't bother throw 10k or more at it and by a LS...🙄
Thanks for educating the younger generation about Chevy high performance in the 1960's. I have a stock 327 with those same double hump heads in my '65 Impala. That big, heavy car can do 0 to 60 in 8 seconds with dual exhaust and powerglide! The power is astounding! My '03 Escalade has a 5.3 L Vortec V-8 with almost as much horsepower as my 327.
Most seem to forget or don’t know that Chevy won the 68&69 Trans-Am championship with a 302 as the rules limited engine displacement to 5 liters. Those engines were and are still making 450-500hp. In 69 they ran against the boss 302 which should have had a huge advantage over every other engine in competition.
Of the sixties cars, there was never a 350 Chevrolet that was rated at 400 or 425 horsepower. As far as I can remember, the biggest horsepower rating for a 350 was the LT1 in the Corvette, which was rated at 370 horsepower, 360 for the Camaro version.
Is there anyway you could test a rounded back cut on the intake. Possibly a short radius vs a long one. It does not matter the head to me it's just a theory.
Until the late 1980s or so this style head was about the only thing a Chevy guy had to pick from. There were a couple of aftermarket heads but the prices back then were crazy. In this day and age we literally are SPOILED with all the parts to choose from. And most choices today are reasonably affordable. And Eric you are correct about the Ford E7TE cylinder head. They max out in the mid 150s on the intake side. They are just horrible stock. To this day I'm still surprised that the Mustang 5.0 ran as fast as it did.
They fit a 283 ! I used them on a 283 w/ 327 / 375 hp cam w/ solid lifters. Amazing how well that worked. Loved had the studs pinned. Built motor in 1969 year I got out of high school.
Was just thinking bout this the other day! . My Dad done a lot of drag racing back in that time period and his daily driver was a 65 Chevelle SS with a 283 and Muncie 4 speed. . It was a solid lifter motor, with a set of the fuelie heads that he had brazed up and cut the B in the shape of the Powerpack triangle to get past tech for limited stock class.😅 That little motor was an absolute screamer, turning high12-13 quarters at a dragstrip in the mountains of rural Appalachia. Loved to pick on unsuspecting hemis with it.
I have a pair of the 291 camel hump heads that are ported out to a 1205 intake gasket. They were in my Chevelle when I bought them and I have no clue who ported then or how far they have been ported. But I've never seen a SBC cast head with ports this big before. I've been an ASE master tech for over 30 years now and I've seen a few cast heads here and there... Some day I need to pull them off and have them flow tested.
I bought a 70 1/2 Z28 Short Block (LT1) with the solid cam 370 hp from my local Chevy dealer back in the early 70's and hit the local bone yards for a set Fulie heads with the double humps. I had the heads reworked and don't knok how much hp it made but it pulled really great!
I remember years ago I had a 383 sbc with those heads on it. I thought it was hot snot. I eventually bought some Trick Flow G2 heads with the canted valves and never looked back. I wasted so much time and money on trying to save money.
I remember sometime around 1990 I spent a fortune getting a set of double humps done with all the goodies. Can't remember for certain but I want to say I had accessorie holes added.
Thanks for the content looking forward to what’s coming in the future. I have a 70 Chevelle with a 406 and a set of old double hump 2.02 angle plug heads. Basically stock bottom end still has dished pistons, Elgin hydraulic flat tappet cam. Basically old school stuff top to bottom. Always surprises people how well it runs in that heavy car.
that was a HOT ticket back when you could find 400,s and just bolt them babies on!!! seen a many with a 280 cam,alum intake cheap headers and be in the 12,s easy.
we are 327 - in the 1960`s = so come on guy your slagging and comparing with total non reality = are you desperate or what ? really not impressed with you ! - 1960`s 327 making 365 hp was fantastic =
I have a set of 461x someone put 2.02 intake valves but left 1.50 exhaust also installed screw in studs I've often wondered if they were worth putting money in them
This may upset some people, but Richard Holdener and Golen Engines have built some exact replicas of these engines and dynoed them, most didn't even make the advertised HP. And that is with the advantage of an electric water pump and open headers. A junkyard 5.3L will make similar power to some of these "legendary" small blocks. I'm in my mid 40s and grew up on the older engines, I like them all.
There are many many variables that are often not optimized, even by many gurus. Ive watched a lot of their videos and some things are NEVER mentioned. Are they secrets or just overlooked? Some are stuck in the 70s, just like their engines.
Pretty sure the only difference between the 487 and 487x is the x version had induction hardened exhaust seats and rotators, usually found on truck engines. Everyone always thinks the x means it's "more better" haha. I can't even count how many I've gone through over the years for roundy round or class drag racing.
You kids! The exhaust crossover passage had a good reason for existing! It was to prevent carb icing and to promote fuel vaporization in cold/damp weather, which greatly helped drivability. In conjunction with these passages, one exhaust manifold had a heat riser valve which had a thermostatic spring that channeled the exhaust through the crossover and out the other manifold. Being spring loaded the valve would open under full throttle, and also open when at operating temp. The system worked quite well if Harry Hammerhand kept his distance!
The exhaust crossover was for cold weather operation. There was a bimetal spring loaded butterfly valve section bolted to the right hand exhaust manifold outlet. When cold, the butterfly valve forced exhaust gas through the intake manifold passage right under the carb to heat it up quickly. The same heat also heated up the bimetal spring in the well in the intake manifold that held the choke closed. The heat from the right hand exhaust manifold opened the exhaust butterfly valve within minutes. My grandma's 64 Impala station wagon with 283 and Powerglide has that butterfly valve even though it was built at the Van Nuys, Calif, plant. She would never drive the car until the green cold engine light on the dashboard went out. My best friend's dad was a contractor and we noticed that his dual exhaust truck didn't sound right. That exhaust butterfly valve was rusted in the closed position. The shaft was seized and we banged it open permanently just for fun.
My friend had these heads and put them on the 327 365 horse version block. What he didn't know was they took LONGER head bolts and ended up stripping out the block trying to get proper torque. He had to put in a bunch of heli coils to bolt on the heads.
Kids is right! Kids are naive. These kids today assume everyone on UA-cam is under the age of 35. I remember a guy putting double hump heads on his Nova. He was so proud of his heads. I was a big block guy. The smog issue hit in 1974, the first solution was to blow fresh air into the exhaust at the heads.
I ran a set of the " big port" 461s on a 337 back in the day . Monster 165cc intake runners , lol. Car ran good .......2800lb 63 nova , Reed 274 cam, torquer intake, small journal 327 block , NOS 125hp plate kit, A1 manual power glide w a 4000 stall and 373 gears . Believe it or not , in the mid 80s , I owned the streets around here. Its still a fairly dead zone for really fast stuff, lol.
And if I have read correctly when I had my 327 they had forged steel crankshafts with the "wide" parting cast line..at least thats what I read in Popular Hot Rodding magazine way back then.
Eric. I have in my junk collection a set of 441 open chamber and a set of 041 closed chamber. Both have some port work. Also need to look i should have a set of 487x heads complete stock. Been sitting for 20 plus years. I bet the shipping to send it all out to would be crazy. Keep the vids coming. I am recovering from open heart surgery and cant do anything right now.
I have 2 sets of double hump heads with bolt holes. One set is slightly modified. The other set is bone stock. This would be an interesting addition for your head test. Let me know if you are interested.
Exhaust crossover was used for choke and to help with warming the engine quicker for street and daily driver use. I still use the 462's on my 69 Camaro, they have 58cc chambers. David Vizard claims that the 2.02 intake valve is too large and actually hurts the flow because of valve shrouding...we always cut them for the 2.02 back in the day, was interesting to see his video
In 1985 I built a 0.030"-over 327 (331) using a large journal '68 forged crank in a '71 4-bolt 010-series SBC block. I searched and found a set of 186 casting heads with 1.94" - 1.50" valves and they were the first heads I ever ported. I studied a lot of books on engine building and heads by Bill Jenkins, Smokey Yunick, Warren Johnson, David Vizard and others. I had the local machine shop machine the heads for 2.02" & 1 .60" valves with 3 -angle valve jobs, screw-in studs, bigger spring pockets and bronze guides. I used TRW forged 11.5:1 pistons, Total Seal gapless rings, and Chevy Pink rods with ARP rod bolts, and the whole rotating assembly was balanced. I don't recall what cam I used (it was almost 40 years ago), but I installed the engine in a little 1976 Chevy Monza 2+2 hatchback with a 4-speed. The rear still had the 2.29 gears in it for about the first year or so and I smoked many Vettes and IROC Camaros. One late night I had an opportunity to run an IROC flat out to top speed on the local highway. We started at 55 and soon the IROC topped out at 165... when I saw he wasn't going any faster I eased down on the gas and easily put several car lengths between us before I let up, just to show I still had more power on tap. I hadn't even topped out, but that car was scary fast and I had already proved it was faster. I eventually installed a Auburn posi-traction and a set of 3.73 gears. which greatly improved off-the-line performance, but at the cost of top-end speed. I still have the 186 heads too.
If you do the cast Iron test.. Then for vortecs use the newer made in Mexico heads.. Seems to be a difference between the old factory heads flowing more than the newer ones GM start using on their 602 crate motors and shelf heads!
The mexican garbage ones on my crate L31 flowed 218 @ 0.450, then fell off to 210 @ 0.500. Engine was always down on power compared to the 7/96 cast Canadian cast 906s.
Eric , Bless you for your incredible talent and knowledge. I use your information constantly , building racing heads and engines. I would Like to purchase your book that you just finished sir. How do I go about getting that from you.
Thanks for sharing that great video Eric. I did not know there were multiple versions of the Camel hump heads. As great as these heads are, they will still never beat a set of 180 cc out of the box Dart Iron Eagles. I watched one video where the iron eagles produced 70 more hp on the same engine on the dyno. But if I recall correctly Iron Eagles weren't even available until the early '80s. I wish I would have had a set of these on my 307 powered '70 Malibu back in the day!
Great video. Just over 900,000 views. Illustrates how an old lower performance aftermarket head will way out perform modified 882 heads. The morons in that comment section scream "apples to oranges" because the whole point of the video went right over their head. The whole point is to show how different in performance Iron Eagles and 882 heads are
My friend got a set of iron Dart heads but, never built the motor. He passed away March of '22. I was in his shop helping move stuff and identifying stuff when I ran across the heads. They had been stored in his garage and one of them was rusty on the deck surface. I'm pretty sure I can save them but, damn!
Yes, i still have the camel hump heads. Had them on a 383 stroker. Nice clean running motor. Broke my yoke on my rear diff , and studs on my right rear wheel. Trial and error when i was young. Theres a kit also that allows you to pin the studs so that they dont back off. Because the studs are pressed in.
I spent a major part of my teenage years scavenging junkyards for these heads. Everyone that had a SBC in the 70s and early 80s just had to have a set. I would do the backyard port work, install the "LT1 Carrrviiitte" springs, guide plates, and studs, and had them sold as fast as I could find and build them. Those heads hold a special place in my heart.
Dude you literally described myself and my best friends growing up ( I’m 58) , except for the selling them off part !🤣
Did the same .My father was the shop mgr at a large gm dealer i got all the engines they swapped out with new 350 & 454 4 bolt blocks.heads etc! I had full run of the machine shop I sold alot of engine parts to buy parts for my drag cars!
...I gotta 350 4 bolt 3/4 cam wit double hump heads and a Holley double pumper.
I got posi too.
Wanna run?
Im that old and never did this! Mid 80’s gm came out with aluminum heads on irocs and corvettes they were dirt cheap ! And flowed better
I grew up in the hood, and we had awesome boneyards back from 19 whenever, till about 1986- There were goodies everywhere if you were persistent and sly😎😂🤙🏼
As an old timer thanks for sharing some stuff my Era. That's all I used to do just a little bowl work and port match. Still got few pairs 461,462 , set of my favorites 3927186 with accessorie holes. Other than the weight of iron. They work just fine. Gotta love old iron
I still use these and 186s on SBC builds to this day. I started building motors in the 70s and these were THE GO TO THING. One JUST went out the door with 186s and all the goodies. They are harder and harder to find and the aluminum head market has become more affordable in recent years. ❤
@@martywilsonwilsonenginesho7940 ihave a set on a sbc build for a 1956 cheverolet truck
The camel humps were still the hot ticket when I was a teenager in the 80s. Those heads, a 70s junkyard truck 400 bored out to 406, 280 cam, 3500 stall, 4.10s, ladder bars, in something light like a Chevy II or Nova, you could run in the 12s for not too expensive if you had your stuff dialed in.
On a side note, the infamous Penske TA race prepped Z/28 cars of the late 60s made 480 HP with 302ci with a cross ram and these heads, ported to Traco's specs. Dual 780 Holleys, pretty radical cam timing I'm sure, but anyway.
Nowadays, I would by the Trick Flow aluminum reproductions of these, they have modern combustion chamber design and will make more power. But these are still super cool for the history involved with them.
so true man.....seen a many 400 stock bottom end with double humps 280 cam hedders take down a many street car man......back before Big money got involved.
There's no wa
way you ran 12s and apparently your lack of knowledge over ci and performance is pathetic
😅
@@chrishensley6745😊
Traco is a name I haven't heard in decades. They knew shit, fact.
My brother and I built a V8 Vega in 1978, and we specifically went looking for an engine with camel hump heads. We found a 275HP 327 4-barrel in a 1968 station wagon that had the camel humps. 1.94" intake, 1.50" exhaust. I think there were also 461 or 462 heads that had 2.02/1.60 valves on the higher power 327, 350, and DZ 302's. 292 (turbo) heads were never sold on production line cars, but they were the ultimate sbc head through the 70's. Then Chevy introduced Bow Tie heads around 1980, in either cast iron or aluminum. Yeah, I'm old.
The 462's had the 1.94" intake valve instead of the 2.02" version,,at least the 462's I had..same nice combustion chambers..I had several of the 461 and 462's..great heads.
Yep... there were several variant of heads cast with "double hump". You'd be surprised how many people think the casting mark alone means "Corvette/Impala 327 fuelie 375hp". It doesn't.
Interesting, I have 2 sets of ported 461 heads, 461 64cc chambers and 461X 58cc, the 461X heads were used in Pro Stock and are thicker steel around each chamber so you don’t break through to water. Always knew they flowed well for a cast iron head. Use 215’s and 58cc heads these days running 12.5:1 comp. Well over 600HP out of 383 cubes.
those 461x,s was the hot ticket....i,m 50...but back in the day they truly made a diff. when there was people that said different.....those were the true high horse small journal double heads from early 60,s till mid 60,s
My 461x heads had the smaller valve set not 2.02 ?? ; took them to Darrell Buell machine shop for hard seats and they broke-thru to the water jackets-- instant junk.
@@MrGGPRI Today they could be spray welded and used again
When I was a senior in high school, mid 80's, in my advanced auto class my auto teacher drew me a picture of the "camel back" head because I was looking for small block to build. I found several SBC in a van inside there was a 283 with "power pack" heads, a 350 with who knows what, then there was the buried motor and it had the holy grail heads on them! Bought it for $150. The motor was a 327 and I thought I was the man when unloading this in the auto shop. Wound up rebuilding them by knurling the guides, 3 angle valve job on the seats, back cutting the valves, shimming the stock springs, then cutting the guides for what we called PC valve seals (the type used today). Bought a Crane cam, Clevite 77 bearings, Victor gasket set, Melling's high volume oil pump, Holley aluminum intake and carburetor. Talk about thinking you were Mr. Hot Rod magazine at 17 years old. It's kind of a bummer that searching/scrounging then putting it all together with your brain and skill for a working combination are sort of disappearing today, t's whoever spends the most money is the coolest now. Another great video.
It was my HS shop teacher that taught me about them also! I always thought up to that point if you put enough cam in something it'd run good. He said you had to get some of these heads and machine them out for 2.02 valves. How right he was!
@gregcampbell3064
Not true at the track. He who spends the least and puts you on the trailer early is king but may not win that day.
Was your teacher Mr Jimmy Peterson ? Sounds like my Power Mechanics and auto tech teacher in 1980-1982..he loved when I took my friends 69' 0r 70' SS El Camino with the factory 396 in it..the best days of my life !
An NHRA Superstock 327/275 with double humps, stock port volumes (165 int/65 exh) (epoxied int, welded exh) 1.94" int 1.50 exh , flat top piston, an intake that has to fit under the stock hood and a QJet make, (an average one (mine),will make 560 hp @ 7400.
Must take a seriously specd out cam to do this?
Very impressive!
I want a video on that one!
@@TRyan-op2jo It's on my you tube dyno channel Merkley Performance. title is Superstock 327
@@tenthousanddays2103
Remember the old stick shift 57 Chevy 283 National record holder? In 86-87'
My since past machinist bought it for a 283 upgraded but never built it back again.
Congrats on 25k subs! I love your videos. I can't wait to be able to buy some heads from ya
I turned 16 in 1984 and double humps were the best we had as a teenager. My stepdad helped me port a set of 186 heads for a flat top 350. He did a 3 angle valve job and picked out a camshaft for me. If I remember correctly it was the 327/350hp specs ground on a 108 lobe center. It ran really well in my 1967 Camaro.
David Vizard has a great video up thats really good, step by step porting tech on the double hunps. He gets about 270 intake flow, enjoy ur channel Eric
On video DV says his ported iron heads are @ $4,000 per pair.
How many do you want?
I just can't sit through his videos, his voice and the way he talks drives me nuts.
I think he had a stroke, if so it's not his fault.
@@bigbelconut he had brain cancer...
He's better now he also has a new channel and is easier to understand...
I built a 327 and ported a set of 194 camel humps using his book as a guide. Lots of careful porting, awesome engine. They dont call him Vizard the wizard for nothing, the man knows his chevy small block performance.
Started running a small fleet of c30 type trucks and a few strip and off-road vehicles in 1980. Cooling the heads was not a bad idea. Greatly helps with engine longevity.. The cross over exhaust port was to help with our cold county engine warm up as well as engine longevity. Still running a couple of those C30's and the 450hp to the ground SBC in a Landcruiser . It's not just the power you need. It's keeping it up and running for years (and miles) that matters.
Great content Eric.
Thanks for sharing.
I built alot of these heads back in the day.
461 and 462.
Great cylinder heads for what there were.
Take care, Ed.
Your right about the 461,462s and they didn't have bolt holes in the front for options like that started doing in the early 70s.
@@BigWood31311969 was all accessories hole heads unless they were leftovers
Thanks Eric,
As a long time sbc fan who cringes every time I hear Ls swap it I'm glad to hear honest critique that doesn't just run the old sbc into the ground and discount their performance capability
LS swappers litterly tell the world that they are not hot rodders. Just bolt on parts is what that world is about and they are like sheep just going with the herd.
Vintage iron requires actuall grinding bending and massaging of parts to make everything optimized and perform in sinc. That's hot rodding. That's a true gear head.
@@shootermcgavin2819 lol that's a little harsh, but funny. What the LS does make super easy is port fuel injection, with the factory computer and HP Tuners. And the factory heads and manifolds flow pretty well right out of the gates. A garden variety junkyard 5.3 with no mechanical issues and a Truck Norris cam will make an honest 415 HP gross if you are a good tuner or have a good tuner. That's pretty attractive to a lot of people. I personally prefer the nostalgia of the SBC, but I can understand wanting decent power without too much fuss.
@Jim Bronson
The Holley Sniper two is here. It all plug and play with any engine or transmission. The dash can be incorporated or you can stand alone literally on Android wifi now. The dreams if the 1990s street and strip are here for mix and match. Old school SBC prior to the 90s with good bottom ends will now shine and piss off a ton of LS power plants in any trim. 350 HD truck blocks with old ported heads and a built 4L60E stall speed and hold beer 😆 wheels up fun!
Today's rings, pistons, and induction with ignition control was really about all they ever needed. You can tell it what to do not what it was asking for 😉 They ran near 800hp blown pump gas on the street back then. Now it's turbos and boost controllers so what is it's limits?
@@kenmoule825 give me the Terminator X over any TBI system. Port injection all the way.
I just built a 66 327 Chevy II block with a set of 291's no porting and the final compression ratio was 11.1 to 1, also with a Crane Cam version of the Duntov 30/30 solid lifter that a guy had in his garage for 30 years and made 407 HP on the engine dyno
Love them 327,s man!
I have a 30-30 solid lifter Cam + lifters from 1969.
Someone is looking for that block man . 😢
@@mikemaguire5507 I have a spare engine, look on Ontario kijiji
@@williepelzer384 Is it NOS
Eric.. you left out the Chevy 292 Turbo heads.. Made famous by Bill Grumpy Jenkins.. you could by them at any Chevy dealership.. They had screw in studs, 2.02 intake and 1.6 ex value and they were 180 cc. Also they were angle plugs. They're were the best.cast iron heads back in the day.. keep up the good work
461X heads had the big intake ports also. As to how good vortec heads are in the 90s we had a costumers 2barrel motor lost a whole point in compression and was still up over 20 hp on a 1.94 vortec. 2.02 valves just hurt flow on them.
Double Humps were so hot back in the 60s and 70s when I was driving Tri-5s and still had money . Building small blocks that screamed and aggravated everyone in our neighborhood . Choppy idle and sounded mean as Hell . oh back in the day . Awesome video .
I have seen 377 SBC with double hump heads made 480 HP to the wheels that in a street car. 10.5:1 compression 107 lsa flat tappet cam shaft and a 750 Holley double pumper carburetor. Rear Gear ratio 3:73
Ported a set of 291’s in 86’, still have them. On a 355 FT with 280H Magnum single plane chassis headers. Totally awesome street power.
Shittt.I ported mine back in 1989 and had them on my motor up until last year lmfao.Finally bolted on some AFR’s.Camel hump head are great heads.
me to...but a early 327 .040 from 90.
Wow! Finally the flow numbers of one of the classics heads of sbc! Eric, I'd love to see the flow #s of the L98 aluminum 113s'
The l98 flows a bit less but they had other advantages. The valves were a touch smaller (though some camel humps on budget engines had pressed rocker studs and the 1.940/1.500" valves) but the chambers were small enough for small engines and would give compression to a dished piston 350 as well.
The flow numbers I've found for the 113 head shows the intake side maxing out right around 198-200 cfm.
Do a Google search on "Stan Weiss cylinder head flow" and see what comes up. He has flowbench data from literally hundreds of different heads.
@@robertwest3093 Lingenfelter was getting 260-270 cfm out of the 113s back in the early 90s with excellent port velocity. I had a pair on a 305 with a XFI 276 cam that made 423 hp @ 6,400 rpm using a single plane intake and GM 2" bore 454 TBI unit.
If I remember the center small port in the head was not for smog , it was used to heat up the intake to help warm up the carb ,to stop cold morning stumble ,hesitation on take off . More for colder climate states . We always used block off intake gaskets for racing . great video to enlighten all the new young guys about the past.
Taking your comment one step further, they also used a heat riser in one exhaust manifold that had a weight and a spring on it. When the engine was cold, idling, the heat riser restricted exhaust flow, which caused the exhaust to pass through the runner under the carb, and out the other exhaust. When the heat riser spring warmed up, it relaxed and allowed the exhaust to exit unrestricted, reducing the exhaust flow under the card.
@@Hoosierdaddy-u2i Right on .
It typically comes back to emissions. Engines make many times more emissions on warm up. So the quicker they can get the incoming air warm and choke off the less emissions they make every cold start. The choke works well enough that it shouldn’t stumble cold. If it does you may need a couple sizes larger primary jets.
@@ztwntyn8 Hate to disagree , Spent a lot of time diagnosing ,carb problems back in the 70s 80s 90s for Drivability complaints , most cold morning start up problems was choke not set right . Timing off , vacuum hose's split ,heat stove pipe missing exhaust choke valve spring stuck ,and of course accelerator pump not working . So as to your possible fix to replace jet size , that was never done ,by me or any other tech . We change jets in carbs mainly for drag racing purposes , in the 2000s to today emissions got way better due to higher compression , better timing and fuel control So after 47 years as a mechanic ,learning everything from points to sliding cam shafts I would say changing jets ,would not be the correct way . 30years GM tech -17yr city fleet tech . My 2 cents
As a kid born in 68, I had a set of 461s but they had1.94, 1.50 exh. Awesome heads...
There's also the 461X heads, which was even better than your standard 461, but they are rare! They were the true holy grail back in the day, but they got sewer size ports.
Yep!! The True high horse small journal early-mid 60,s double hump.
There was also the GM sbc (370) castings which were a fully closed chamber head but with accessory holes drilled for long waterpump stuff. For that reason. I always tried for those if when I could get them. They port up well and were a great alternative.
me too...most dont know that...same as 186,s landed a set cheap last year
I still run a set of 186,s on my 355 with a Procharger. Installed larger valves.
From the numbers I've seen, all but the 186 double humps should flow enough at 0.500 lift in stock form to make 400 horsepower. The LS guys do have a point though. They can do it with less compression and a more street friendly cam. For example, even the early 2.00/1.55 valved LS-1 806 heads flow a bit more at 0.400 than 461 DH's with 2.02/1.60 valves do at 0.500 and the '97 LS-1 made 345 net HP with a kitten like idle.
That said, I still think it's blasphemy to swap an LS into a classic.
Lol I got 2 LS motors sitting in the garage I'll probably never use!! I'm going to build a 400 sbc soon@!
Old 300 Horse 327 Cubic Inch Heads... even found in late sixties 4 door grocery gettin Impala's and Wagons. Porting, Static Compression and the Right Cam... they set a couple of National Records back in the day with a few tricks on the side. One of the long-term engine builders in my area told me they converted them to angle plug heads to aid in part flame travel across the dome. (suspect dome mass had a part in moving the plug too)
What about a set of 492's
I’ve watched this video like 3 times now, the double humps we’re getting phased out in mid 90’s when I began, still cool though and respect them as well as their legacy. I’d like to send you some big block Olds heads to flow, they were cut for the “big” BBO valves, minor blend (like these 491’s), the AIR bumps in the exhaust runners smoothed and intake valves were back cut.
As an Engineer... Love the comments! I still curse other Engineers daily....
LOL so true. And it seems like the engineer with the worse idea always gets the go ahead.
I always say, "the worse the engineer, the better my friend". I make my living from fixing problems that others can't, and at least 80% of my work is the direct result of bad engineering. It sounds like you and I will never be friends 😂😂😂
The double hump heads with the accessory holes were casting number 186. There were also an early seventies head that didn’t have the double humps that also had accessory holes that were performance factory castings with the 64 cc chambers that were casting number 041. I have a pair of those. Chevy also made casting number 292 heads that were angle plugs but were never offered on a factory car. They were off-road use only and were also the version that many of the aftermarket heads afterwards were designed from.
Had angle plug heads in 90s on my 350 no problems mild cam rollers 750 TRW pistons t400 3.7s run 12.8
We angle milled those camel humpers so far that we had to plug the cooling holes for the spark plugs. So much work was involved to do that to correct the head geometry but that`s what happens in spec circle track racing
I have a old pair of 1968 041s off a 1970s Modified Production class engine that flow 270+cfm. Car ran mid 10s with them. They are hogged out to the point that they pretty thin, id be afraid to use them on the street. Plus theyve been milled alot. Intake valves hang lower than the deck.
The factory used an unshrouding tool on a drill press for all SB. 202 ,160 valves. A 40 thousands up to 69 and than a 35 up to 1980 .because if you didn't they flowed worse than the 196/ 150
aweshome. Hey this is crazy i am really know it, although tell me what you think if it would run ok until i make this 355 a 396. Brodix IK 210cc heads. Ok on a 355 with 11:1 compression and ported RPM non air gap or?, and XR300HR cam or smaller on 106^ LSA and ICL. 3200 lbs. street camaro 2nd gen. No pwr steering. No pwr brakes. just alternator and waterpump. Want to disguise it gm corporate blue with 305 valve covers. 3.73 gears. BFG tires.
Back in 1974, i was building lots of sbc engines. It wasn't too hard to get 350hp out of a 350. And have it very streetable. I built both the straight and angle plug heads. I found that the 194 straight plug heads were better for street use unless you had a reason to wind your motor over 6200+. Who does that? Only if your rich. (Not me) And we had the problem with octane going down. Now the 202 angle plug heads were great for serious street use and racing. But i had problems with drivability and plug fouling if the motor wasn't tuned perfectly every time. Excellent review. Takes me back to the good old days when building the sbc was simple, fun, and somewhat cheap.
⁰ò 00pm ź4wz3ez434
I had a bad experience back in the day with the 461 head and specifically the 461X which purportedly was an extra hi-flow 461 but for some reason had the smaller valve set ?
So back in the early ’60s bought a 327/340hp out of a totaled 1962 Corvette. Put this engine in my ’32 roadster with a T-10 and it was a screamer. When leaded fuels left us, send the heads over to an engine machinist for hard seats. Well, said machinist later calls me with the “news” that he went into the water jacket on both heads (why not stop at the first head ?); apparently the “X” meant very thin castings to get more flow ?
In retrospect, in a light 2400lb car which would never see heavy loads, I should have left the heads alone instead of doing the “right thing” and ending up with two boat anchors.
I still run a set of 186,s fully ported with larger valves with a Procharger on a 355. Building a 383 with AFR 195,s.
"you know how many engineer bad ideas there are" excellent point
186 double humps started in 69. Basically the exact same head as the 461 with same 64cc chamber but with accessory holes. Commonly seen on the 302 DZ engine, 350-300hp and the LT-1 350-370hp. The higher HP versions with 2.02/1.60 valves. Hope that helps.
One of these days Eric I'd love to see you review the Trick Flow version of these hump heads. They reproduce an aluminum version for those of us that like stealthy, but are enhanced a bit with modern chambers, larger runners etc... I've been meaning to order a set for a build I've had on the back burner.
186's had a 462 chamber
@@Levisnteeshirt1
They were 64cc. In fact the factory 2.02 valve version is easy to tell as they actually had a machined relief in the chamber for the valve from the factory. The 1.94 version didn't have that.
These little heads were pretty good for way back in 1960's
And I'll take a set today for next to nothing for building a grocery getter...
I had a set of 461X heads on a 350+60 , Lunati 300-310 duration 507 lift 650 dp Hooker headers , pretty stoud back when I was 19 , 65 now
No the heat crossover was used to keep the carburetor from icing up, especially in colder weather
Wrong. Intake heat was for fuel atomization. It is also why you look into the plenum of a factory intake and see ribs at the bottom. It was for converting the fuel droplets into vapor. That is also why many older engines would run a little rough at start up and then start running smooth after a minute or so. The vaporized fuel distributes more evenly.
@@beestoe993 100% the heat crossover is used to keep the carburetor for icing up this is common knowledge isn’t even a controversial comment not even a little bit, I’m sure efficiency may have been a byproduct as well but the main reason was to keep the throttle blades from icing up
@@DSRE535 SMH. Believe whatever you want, I told you the truth.
I just picked up a little hopped up h.o. 305 that the guy built a 335 stroker with and it has the 462 DH heads and i am plucking them off it to toss on my 383 as i have bought 4 sets of vortec heads and there has been cracks in 7 of the 8 heads, i am done spending money on the thin poorly made vortec heads, i think these little 462s will do me just fine with my flat top 10-1 pistons with the steel shim gaskets i should be right at 10.5-1 so i should still be good on pump gas, can't wait to go from the 76cc heads with .046 gaskets to the 64 cc and .015 gaskets to see what kind of difference there is, the heads have had a slight clean up done to them and gasket matched, nothing to big but should do ok, i hope! :)
I built back in 2000 a 383 with 461's
Making about 450 HP The car is a 1980 Firebird I run at Gainesville, FL. 1/8 mile 7.55 and 11.7 1/4 mile.
461's are good Heads. !!! PS. 110 VP Gas 13 to 1 compression.
There are 2 heads that were the same as a double hump but didn't have the double hump markings..040 with no bolt holes and 041 with the bolt holes.people passed them up because they didn't have the humps
I had a set of 492s on a 350 I built back in 1993. They were not angle plug heads, and they were 1.94/1.5 but they were still good for 300 HP on a 1988 Caprice. The 492s were available either as straight or angle plugs. The 492s also had the accessory drive bolt bosses/holes drilled in them where the earlier heads, like these 461s, did not. There were also 462 heads that were of this vintage and the difference was the 461 was a 'closed chamber' head and the 462 is an 'open chamber' head. The 492 is the same as a 462 but with those bolt holes in the ends. Also, the extended water jacket allowed them to get more compression on pump fuel at the time, these were 30 years before the 'reverse flow' SBC Gen 2 engines came out (the LT1/LT4). The exhaust port in the middle of the intake side is for a 'heat stove' under the intake plenum, which facilitates faster engine warm up times by allowing the heat to better vaporize the fuel coming out of the carb. It's not for emissions, it's for driveability.
292x casting head I believe we're done in two versions, of course angle plug, one had 185 cc intake, the other 200cc, I always thought Ole Smokey had a key to all manufacture back door, smokey influenced the 200cc intake, they are one cover of his book
This is off the top of my head. 461’s were the “Fuelie head”, in -65 they had the 461X, that was the 375 HP 327 Rochester Injected Vette.
292 was a mid -70’s Chevy Performance head, I remember them being referred to as “Turbo heads”, not that there was any turbocharging in the picture. Then in the late -70’s / early -80’s, is when the “Bow Tie” parts came into being.
we won 11 super street dirt races in early 90s with 1 .94 291 350 .500 lift. protested 2× (202s were legal).
292x was a 64cc angle plug
I had the x block too
292 had no heat crossover, were never put on street cars
@@No1414body Over the counter only for 292’s and possibly 492 also. I’ve got a set of 1973 492’s that were bought OTC.
@@stevewalters6853 that is correct, had to buy the at the Chevy dealer bare only
@@No1414body Eric said 086 were dbl hump with accessory holes but it’s 186’s not 086. I got a OTC 68 327 CE block with 186’s screw in studs and guide plates. People said they ask for a Corvette 327 at the parts counter when they bought it heads are dated 12/68.
The heat riser was for the choke as well as getting the carb warm.
Fuel was much better
I grew up hearing about them double hump heads old timers be arguing who’s is better lmao 🤣 in the south the arguments about heads get weird on guy said he’s where so good they was triple hump heads
The big disadvantage to vortec heads is that 80%of them are cracked and the rest will eventually crack! The early chevy heads(pre amog) rarely cracked unless you were doing something really extreme.
Thanks very much for that great video.... I've just put a set of 461s on a 350 I've put together at home for a mild jetboat motor.. Cam intake exhaust flat top pistons etc... Every one said go LS... Out here in New Zealand but I don't have the money for LS... It certainly makes me feel better now that I'm on the right track with making some old school power... Hopefully it makes at least 300hp😬 most guys were saying you'll be lucky to get 250hp...don't bother throw 10k or more at it and by a LS...🙄
Thanks for educating the younger generation about Chevy high performance in the 1960's. I have a stock 327 with those same double hump heads in my '65 Impala. That big, heavy car can do 0 to 60 in 8 seconds with dual exhaust and powerglide! The power is astounding! My '03 Escalade has a 5.3 L Vortec V-8 with almost as much horsepower as my 327.
Most seem to forget or don’t know that Chevy won the 68&69 Trans-Am championship with a 302 as the rules limited engine displacement to 5 liters. Those engines were and are still making 450-500hp. In 69 they ran against the boss 302 which should have had a huge advantage over every other engine in competition.
Richard Holdener did a video comparing the dyno performance of the DZ302 and Ford 302 Boss engines. Search for it on UA-cam.
Of the sixties cars, there was never a 350 Chevrolet that was rated at 400 or 425 horsepower. As far as I can remember, the biggest horsepower rating for a 350 was the LT1 in the Corvette, which was rated at 370 horsepower, 360 for the Camaro version.
Is there anyway you could test a rounded back cut on the intake. Possibly a short radius vs a long one. It does not matter the head to me it's just a theory.
Ive run some double back cuts
I had a pair of those one ninety four close chambered . I put 2.125 nose. On a loose but good bottom end.
Ran like a bat out of hell..
Dude, my hats off to you! How do u find time to offer videos? Head porting takes a lot of time
In Sweden we call these Mickey Mouse heads, due to the humps looks like Mickeys ears
Eric, the 461 X heads are the best. Also, the 462's are good.. the combustion chamber is a little larger than the 461's
Until the late 1980s or so this style head was about the only thing a Chevy guy had to pick from. There were a couple of aftermarket heads but the prices back then were crazy. In this day and age we literally are SPOILED with all the parts to choose from. And most choices today are reasonably affordable. And Eric you are correct about the Ford E7TE cylinder head. They max out in the mid 150s on the intake side. They are just horrible stock. To this day I'm still surprised that the Mustang 5.0 ran as fast as it did.
They fit a 283 ! I used them on a 283 w/ 327 / 375 hp cam w/ solid lifters. Amazing how well that worked. Loved had the studs pinned. Built motor in 1969 year I got out of high school.
Was just thinking bout this the other day!
. My Dad done a lot of drag racing back in that time period and his daily driver was a 65 Chevelle SS with a 283 and Muncie 4 speed. . It was a solid lifter motor, with a set of the fuelie heads that he had brazed up and cut the B in the shape of the Powerpack triangle to get past tech for limited stock class.😅
That little motor was an absolute screamer, turning high12-13 quarters at a dragstrip in the mountains of rural Appalachia. Loved to pick on unsuspecting hemis with it.
I have a pair of the 291 camel hump heads that are ported out to a 1205 intake gasket. They were in my Chevelle when I bought them and I have no clue who ported then or how far they have been ported. But I've never seen a SBC cast head with ports this big before. I've been an ASE master tech for over 30 years now and I've seen a few cast heads here and there... Some day I need to pull them off and have them flow tested.
468 double humps on 79 z 28 had the large chamber but the ports were identical to the 462
I bought a 70 1/2 Z28 Short Block (LT1) with the solid cam 370 hp from my local Chevy dealer back in the early 70's and hit the local bone yards for a set Fulie heads with the double humps. I had the heads reworked and don't knok how much hp it made but it pulled really great!
Well guess the old Chevy heads and blocks I got laying around might be worth something after all great video you made a old hot roders day .
Guess who else were professional engineers. The people who built the titanic
I remember years ago I had a 383 sbc with those heads on it. I thought it was hot snot. I eventually bought some Trick Flow G2 heads with the canted valves and never looked back. I wasted so much time and money on trying to save money.
Thats why ported iron heads cost $4,000. TIME.
Nobody would run them except in restricted nostalgia classes.
I remember sometime around 1990 I spent a fortune getting a set of double humps done with all the goodies. Can't remember for certain but I want to say I had accessorie holes added.
Could you please do a set of world products sportsman 2 or dart 2 as they used to be called in youy cast iron test.
He did a while back if you scroll down you can find it
Thanks for the content looking forward to what’s coming in the future. I have a 70 Chevelle with a 406 and a set of old double hump 2.02 angle plug heads. Basically stock bottom end still has dished pistons, Elgin hydraulic flat tappet cam. Basically old school stuff top to bottom. Always surprises people how well it runs in that heavy car.
that was a HOT ticket back when you could find 400,s and just bolt them babies on!!! seen a many with a 280 cam,alum intake cheap headers and be in the 12,s easy.
we are 327 - in the 1960`s = so come on guy your slagging and comparing with total non reality = are you desperate or what ? really not impressed with you ! - 1960`s 327 making 365 hp was fantastic =
Ok
I have a set of 461x someone put 2.02 intake valves but left 1.50 exhaust also installed screw in studs
I've often wondered if they were worth putting money in them
Sell them to me
@@BillWilliams-p4o ill sell them
@@jeffmoseley4053
? 🤔
@@BillWilliams-p4o 500.00 plus shipping
This may upset some people, but Richard Holdener and Golen Engines have built some exact replicas of these engines and dynoed them, most didn't even make the advertised HP. And that is with the advantage of an electric water pump and open headers. A junkyard 5.3L will make similar power to some of these "legendary" small blocks. I'm in my mid 40s and grew up on the older engines, I like them all.
There are many many variables that are often not optimized, even by many gurus.
Ive watched a lot of their videos and some things are NEVER mentioned. Are they secrets or just overlooked?
Some are stuck in the 70s, just like their engines.
Best heads ever built by Chevy back in the day were the 292 angle plug heads! Awesome flow for stock heads.
Highest flowing large chamber SBC head is the 487X but they’re really hard to find. Any head ending with “X” is the best version of that casting. 👍
That's a '72 LT1 Vette head!
Pretty sure the only difference between the 487 and 487x is the x version had induction hardened exhaust seats and rotators, usually found on truck engines. Everyone always thinks the x means it's "more better" haha. I can't even count how many I've gone through over the years for roundy round or class drag racing.
441s are the best flowing production SBC head bare none.
I have a set of 487X heads for my 72 corvette. Right now I have a set of 1970 186 heads on it.
041 has accessorie holes
You kids! The exhaust crossover passage had a good reason for existing! It was to prevent carb icing and to promote fuel vaporization in cold/damp weather, which greatly helped drivability. In conjunction with these passages, one exhaust manifold had a heat riser valve which had a thermostatic spring that channeled the exhaust through the crossover and out the other manifold. Being spring loaded the valve would open under full throttle, and also open when at operating temp. The system worked quite well if Harry Hammerhand kept his distance!
I believe the crossover port was for cold weather operation to help prevent fuel from condensing out in the manifold and to aid in startup.
These “camel” heads were very popular in South Africa as well my dad had a pair on his oval car did really well 🏁
It would be interesting to see the original compared to the trick flow aluminum double hump heads.
The exhaust crossover was for cold weather operation. There was a bimetal spring loaded butterfly valve section bolted to the right hand exhaust manifold outlet. When cold, the butterfly valve forced exhaust gas through the intake manifold passage right under the carb to heat it up quickly. The same heat also heated up the bimetal spring in the well in the intake manifold that held the choke closed. The heat from the right hand exhaust manifold opened the exhaust butterfly valve within minutes.
My grandma's 64 Impala station wagon with 283 and Powerglide has that butterfly valve even though it was built at the Van Nuys, Calif, plant. She would never drive the car until the green cold engine light on the dashboard went out. My best friend's dad was a contractor and we noticed that his dual exhaust truck didn't sound right. That exhaust butterfly valve was rusted in the closed position. The shaft was seized and we banged it open permanently just for fun.
All stock 461 & 462's had press on studs...
My friend had these heads and put them on the 327 365 horse version block. What he didn't know was they took LONGER head bolts and ended up stripping out the block trying to get proper torque. He had to put in a bunch of heli coils to bolt on the heads.
About to try some on a twin turbo 383
Kids is right! Kids are naive. These kids today assume everyone on UA-cam is under the age of 35. I remember a guy putting double hump heads on his Nova. He was so proud of his heads. I was a big block guy. The smog issue hit in 1974, the first solution was to blow fresh air into the exhaust at the heads.
My 2700 lb 74 vega runs 11.76@115 with camel humps heads.1.94 in/1.5 ex.Only bowl ported...355,flat tops,Isky 274 mega/226 @0.50in/226@0.50 ex ,490/490 lift.Comp full roller rockers,rpm,3310 750 Holley with metering jet block.Turbo 400/3000 stall.Mopar 8 3/4 with 3.23 gears and posi,with 235-60-15 drag radials.1.43 springs,7/16 rocker studs.4.10 gears=11.40s easy.
I ran a set of the " big port" 461s on a 337 back in the day . Monster 165cc intake runners , lol.
Car ran good .......2800lb 63 nova , Reed 274 cam, torquer intake, small journal 327 block , NOS 125hp plate kit, A1 manual power glide w a 4000 stall and 373 gears . Believe it or not , in the mid 80s , I owned the streets around here. Its still a fairly dead zone for really fast stuff, lol.
And if I have read correctly when I had my 327 they had forged steel crankshafts with the "wide" parting cast line..at least thats what I read in Popular Hot Rodding magazine way back then.
Eric. I have in my junk collection a set of 441 open chamber and a set of 041 closed chamber. Both have some port work. Also need to look i should have a set of 487x heads complete stock. Been sitting for 20 plus years. I bet the shipping to send it all out to would be crazy. Keep the vids coming. I am recovering from open heart surgery and cant do anything right now.
Finally! Old iron
I have 2 sets of double hump heads with bolt holes. One set is slightly modified. The other set is bone stock. This would be an interesting addition for your head test. Let me know if you are interested.
If they are factory bolt holes. The heads are 186 with small humps. Or somebody drilled them. But you can do that just silicone them. Work fine
1969 and up heads with the accessory bolt holes.
Exhaust crossover was used for choke and to help with warming the engine quicker for street and daily driver use. I still use the 462's on my 69 Camaro, they have 58cc chambers. David Vizard claims that the 2.02 intake valve is too large and actually hurts the flow because of valve shrouding...we always cut them for the 2.02 back in the day, was interesting to see his video
He is wrong.
Need to add stock vortec heads to that upcoming sbc test.
I built an 11:1 SBC in 79' with a solid flat tappet Isky short oval cam, single plane intake and it ran pretty well in a 68' Camaro with 4.56 gears
In 1985 I built a 0.030"-over 327 (331) using a large journal '68 forged crank in a '71 4-bolt 010-series SBC block. I searched and found a set of 186 casting heads with 1.94" - 1.50" valves and they were the first heads I ever ported. I studied a lot of books on engine building and heads by Bill Jenkins, Smokey Yunick, Warren Johnson, David Vizard and others. I had the local machine shop machine the heads for 2.02" & 1 .60" valves with 3 -angle valve jobs, screw-in studs, bigger spring pockets and bronze guides. I used TRW forged 11.5:1 pistons, Total Seal gapless rings, and Chevy Pink rods with ARP rod bolts, and the whole rotating assembly was balanced. I don't recall what cam I used (it was almost 40 years ago), but I installed the engine in a little 1976 Chevy Monza 2+2 hatchback with a 4-speed. The rear still had the 2.29 gears in it for about the first year or so and I smoked many Vettes and IROC Camaros. One late night I had an opportunity to run an IROC flat out to top speed on the local highway. We started at 55 and soon the IROC topped out at 165... when I saw he wasn't going any faster I eased down on the gas and easily put several car lengths between us before I let up, just to show I still had more power on tap. I hadn't even topped out, but that car was scary fast and I had already proved it was faster. I eventually installed a Auburn posi-traction and a set of 3.73 gears. which greatly improved off-the-line performance, but at the cost of top-end speed. I still have the 186 heads too.
If you do the cast Iron test.. Then for vortecs use the newer made in Mexico heads.. Seems to be a difference between the old factory heads flowing more than the newer ones GM start using on their 602 crate motors and shelf heads!
The mexican garbage ones on my crate L31 flowed 218 @ 0.450, then fell off to 210 @ 0.500. Engine was always down on power compared to the 7/96 cast Canadian cast 906s.
Eric , Bless you for your incredible talent and knowledge. I use your information constantly , building racing heads and engines. I would Like to purchase your book that you just finished sir. How do I go about getting that from you.
Thanks for sharing that great video Eric. I did not know there were multiple versions of the Camel hump heads. As great as these heads are, they will still never beat a set of 180 cc out of the box Dart Iron Eagles. I watched one video where the iron eagles produced 70 more hp on the same engine on the dyno. But if I recall correctly Iron Eagles weren't even available until the early '80s. I wish I would have had a set of these on my 307 powered '70 Malibu back in the day!
Great video. Just over 900,000 views. Illustrates how an old lower performance aftermarket head will way out perform modified 882 heads. The morons in that comment section scream "apples to oranges" because the whole point of the video went right over their head. The whole point is to show how different in performance Iron Eagles and 882 heads are
My friend got a set of iron Dart heads but, never built the motor. He passed away March of '22. I was in his shop helping move stuff and identifying stuff when I ran across the heads. They had been stored in his garage and one of them was rusty on the deck surface. I'm pretty sure I can save them but, damn!
Yes, i still have the camel hump heads. Had them on a 383 stroker. Nice clean running motor. Broke my yoke on my rear diff , and studs on my right rear wheel. Trial and error when i was young. Theres a kit also that allows you to pin the studs so that they dont back off. Because the studs are pressed in.