Very nice Eric, I think that this will be a great series. You don't see many sets of 492 heads. Yours are in nice shape.👍 Nice cutters.👍 Thanks for sharing.👍🇺🇸👍
Performance Automotive Warehouse. My go-to until Jegs and Summit came along. JC Whitney had good prices on parts too. Yep, I am getting old but not slow, lol.
Loved PAW, built my first MoPar with stuff from there and "Direct Connection," since I worked at the local Chry-Ply dealership. Also built other makes, including Buick 455s with the selection of parts they carried, most shown in that giant catalog!! A friend (RIP) had some early DART heads that his uncle got on a crate 355, bought directly from Racing Head Service. His uncle was a truck driver and used to pass them in Tennessee and stop in. When he upgraded his '69 Camaro, he bought and hauled the long-block (with 280H Comp cam and the Dart heads) back to Georgia for installation. When my friend got the engine (the Camaro got totalled in a DUI-caused wreck), we tore it down and freshened it, with another dual-pattern (Extreme 4x4) Comp camshaft. The DART heads actually had "double humps" cast right in, like a stealth modification, but were clearly cast with the "DART" logo under the valve covers. I think they had 180-200cc runners, screw in studs, etc. and were HEAVY!
Going by memory, so take that for what it's worth. 492's came with various options; 1.94/1.50, 2.02/1.60, straight plug, angle plug, screw in studs or pressed in studs, all with different part numbers (same casting number though). Now, for making them go-fast, the over the counter 492's were referenced the Chevy Power book, where they recommended using a 2.4" cutter to unshroud the intake valve vs the 2.34" cutter from the factory. Also, but not stated in the Chevy Power book was the need to "blend" the bottom cut to the bowl with a 70 (75?) degree cutter to blend within a 1/16" or so to the 60 deg cut. When "stock" heads were required in stock and super stock, we could get the cutters to match the factory chatter so that they would still look stock to the tech officials (back before cc'ing the ports and "do whatever you want as long as the cc matches" rules came into effect). Obviously angle plugs were never on production cars, so we were limited there. This was an NHRA accepted replacement head for some engine combos. The 292's would still outflow them and also lacked the exhaust crossover. If heavily ported, the 292's would crack too. They'd be fine for drag racing if welded back up, but wouldn't last in Cup/Grand National like that. If you compared the 492 and the 292, the 292 would flow more, but were more "fragile," at least in my experience in both drag racing and circle track racing at the time. The last set of 292's (drag racing) I owned were ported so much near the pushrod pinch that the slot was just left open, then a piece of sheet metal was brazed to the slot on the pushrod side and the port re-blended. Even with all of that work, they would still flow just under 300 cfm @ 28in Hg. Obviously much better heads are available today, but that's all we had back then.
PAW!! I remember that company. They had a location in the neighborhood I grew up in. The catalog was an amazing compilation of goodies that was thick as an unabridged dictionary! I left more than a few paychecks with them, in exchange for toys, lovely toys that made good power happen.
I had a 388 back in late 80s that made 580,590 horsepower with a set of angle plug double humps. McCormick engine's built that one for me. It had wolverine cam flat tappet solid lifter 1.6 rockers. About 550 intake lift and 570 exhaust. Cam was same as Elgin 2nd generation. Really good running small block. He ported the heads. 11.2 compression. I ran hooker super comp 1 7/8s header. It can be done but takes some work to get there. I appreciate your work and all you bring light for your viewers.
The 492 heads were production, and could have either 2.02/1.60 or 1.94/1.50 valves with the pressed in studs and straight spark plugs like yours has. The 292 heads were the over the counter heads from Crower or Crane one or the other, and had the angle plug, screw in rocker studs, and 2.02/1.60 valves. These were the "turbo" heads.
Interesting to see the lower performance 492. I have a ported set that started out with factory guide plates and screw in studs along with the angle plugs. They run great on the 383 in my truck and were originally cast in 1975. I have a short video on them if anyone would like to see. Thanks for doing this series Eric!
Still have my 97 PAW catalog. It’s a great reference source! This is going to be an awesome series! Still a double hump fan- yes I know they suck compared to what is currently available.
Getting power out of stock type heads will always be cool! PAW was amazing, I miss it. That was a lot of material on that valve job, looking forward to seeing the numbers after the blend.
Man I remember porting a set of 291’s back in 84’! They were 1.94/1.5 but they turned out really nice, and made good power. Oh and the PAW catalog was the Bible of speed parts!
PAW !! I bought a "3/4" race cam from PAW for a 1971 400 small block that I bought for $25 in 1979. Went into a 72 SS Camaro that I bought (for $500) with a blown engine. Installed it with the 350s intake/carb and headers......fired it up and it vibrated horribly !!! 1979 I learned a valuable lesson about sbc 400s. $90 flywheel and this thing ran hard!
Try David Vizards porting on his 562 hp. Small Block video, I did it for my truck pulling guys with great results , mine were 461 castings, Im this gals hubby, I called you about a spacer several months ago, i must say you sounded like a real gentalman.May come see you some day.Keep up the great work.And... Been waiting for someone to do these early cast heads,
I have always loved SBC engines, with that said the chevy small block has a distributor and oil pump that runs perpetual to the crankshaft. That in itself is a big hurdle to cross. Then the LS is a skirted block and has 6 bolts per main cap. Will be far more reliable with increased hp. So flow all you want, take a SBC and an LS of a certain size and the LS should prevail. Plus how many of these heads do you think are available 💁♂️
Eric, I still have a carbide radius to angle cutter to duplicate the chamber unshrouding on the factory production 2.02 heads. I've also seen a set of 492 straight plug heads that were the crane cams ported version, IIRC they called them "fireball" heads. Converted many sets of factory castings to the HP factory style, ie: screw in studs, guide plates, convert to 2.02 & 1.6 valves. I recall an article complete with dyno testing, on a 355ci, 600hp circle track SBC build that used ported 292 turbo heads. This was way before anyone openly discussed air flow in CFM and likely predates any commercially available flow benches. I'd like to see what a set of nearly 300 CFM factory turbo castings look like. I recall a lot of crack related issues with them even in unported condition.
Just for the record. The 492 heads on my small block are screw in studs and angle plug. I have never removed them from my engine to see valve size but they're working great and daily driven!
PAW closed down in 2011, turned in to Vintage Speed equipment , mostly Flat head and old G1 Hemi parts. I'm too young to have ever bought anything from the catalog, but I do have a few copies of the older catalog,
I ran mildly cleaned up 492’s on a 1995 short block w/ 214/224 cam, th350 w/3200 converter and 3.42 gears. 1985 S10 Blazer Ancient BFG DR’s 100 shot went 7.90’s 1/8th first time out. Decent for a DD
Had a 68 Impala factory 327 375 HP 400 Turbo transmission, 12 bolt posi.... Custom coupe ....had short top hideaway headlights..... Engine labeled on valve cover...Tanawanda Racing team.... chrome labels.... anyway had those same Head casting.....My Mother was rear-ended and totaled it I ran the engine and transmission and rear end in a 68 GMC short wide with leaf springs...I remember it well because I done a Valve job and cam replacement at low mileage ....had burnt valve....I put the same came as the 302 Duntov grind.....and accel distributor and wires.. around 1977....
These were a "service replacement" for all the "double hump" heads from about 1971 - on when machined for straight plugs and press in studs. They did have extra meat around the valve spring seats, and around the valve seats themselves, compared to earlier versions. These castings were also factory machined for angle plugs and screw in studs. Nice heads ! While I still have a huge soft spot for the original small block Chevy, I think the power production of a bone stock 4.8 or 5.3 LS shows that there is way more to horses than raw head flow #'s.... The combustion chambers in the base 706 heads are far more efficient than the camel humps, and add to that the directed swirl caractoristics of the LS heads. It makes a real difference. That being said, I'd love to see an apples to apples comparison on same cubic inch engines using factory head castings and comparable cam specs. It would be interesting o see how much work it would take to get the factory small block heads to make as much HP as untouched base 706 heads. I have a really nice set of 461's that I may "fluff up" and throw on a 350 that I have just for some old school fun.
Those heads were available on production cars. 1970-1971 LT1 engines I think. Only the straight plug version. The 492 with angle plugs was gm parts counter only.
1969 L-46 186 1970 L-46 187 1969-1970 L-46 Replacement Engine 492 1970 LT-1 414 1970 LT-1 Replacement Engine 492 1971 LT-1 was a large chamber head to give 9.0:1 Comp with the new Flat Top Pistons (330 bhp gross).
492 were the 462 casting with accessory holes, there were the 292 angle pluggers, with 200 right at it cfm intake runners, for the street driver that head you have works great
The head you got was basically a 350/300 head that’s why no screw in studs and guide plates my 492 ‘s due have the 2.02/1.60 valve angle plugs and screw in studs with guide plates, this first series they tilted the plug up so flame travel went over the piston dome, then with the angle of the plug it was a great option over the stock head and still nhra compliance, the head like mine had the unshrouding in the combustion chamber so on 302 or 350 with 11 to one or greater pistons they worked very well
My dad had a set of those heads on his 67 Nova SS, L79. with a Duntov 030/30 camshaft. That thing was so docile under 2500 RPM, Get over that & it would unleash the Kraken, all the way to 6300 RPM. 4:11 gears with 60 series 14" wheels, and believe it or not, a close ratio saginaw 4 speed. First 3 gears sound/act like first gear. The one & only time he took it to the strip, it turned a 13.20 at 110, if memory serves.
What double jumps with accessory holes was on the 70ish lt1. Had a buddy that bought a 74 Monte Carlo that had a lt1 with double humps but had bolt holes. Thanks for the content.
Find a 461 or better a 461x for flow testing; reputed to be at the top of the "double-humps"..Had a set of 461x heads that were ruined when a "reputable" engine machine company tried to install hard seats and cut into the water passages. The 492s shown here are late versions with threaded accessory mounts at the ends. Still have my PAW catalogs and a bunch other vintage suppliers.
from experience u can build the hell out of a 202 head it cost me 3800 to build up a set but we ported every thing made them 204 and ported the intake ports and the intake to match the new ports plus we needed it to drop oil fast and more water for high rpms we even polished the block for oil drop with cast on cast way less head gasket problems i never lost the head gasket even over heating but i did twist a few crank off the front still running belts for the street
About 20 years ago i had a set of 492 heads with 202/160 valves on a 408 in a 68 Chevelle, i drilled the steam holes in them and it never ran over 210 degrees even when on it hard. It pushed around 480hp and was a hard pulling motor even bouncing on the rev limiter would still pin you to the seat. Wish i wouldnt have sold it now.
i had 292 angle plug heads AND some 492 angle plugs. Bought from a circle track racer in the late 80's. Ran real strong, they were very heavily ported, but anyhow, my 492's were angle plug.
Yes, what you mentioned at the end has led to interesting results. Not many use the 706 heads because of low flow numbers. They have the 61cc chambers you can mill down to around 56cc or sometimes more. 2 tests from Holdener an another I saw found the 706 heads easily beat all other factory ls heads. Some of them by a lot. The extra flow never overcomes the compression you lose. So many people took off their 706 heads for other factory or even aftermarket heads the make a bunch less power. If I remember correctly the 2 casting numbers that have been touted as the ultimate factory heads for swaps actually came in absolutely last when actually tested due to big combustion chambers.
This is a short version so if you want more info search and it’s there. There are other tests too. I think this one is from when he worked for motortrend originally. ua-cam.com/video/zfK45BqEo1Q/v-deo.htmlsi=xk4BMxqlhUQnG-_v
I have a pair of 492's 2.02 screw in studs and angle plug I wonder why angle plug heads had the same casting #. Can't wait to see if they are worth using.
Watch out for castings with out accessory threads PAW story: PAW had random subcontractors grinding cranks. Subs pushed the steady rests in to hard so they could grind quicker with rough stones. You can guess what this did We reground lots of PAW cranks, some were so bad that they would not clean up at .040 Not a place to get shelf cams either.
The late Joe Sherman did many articles and builds in hot rod magazine. He did high rpm crazy build!! He like the “turbo” heads or double hump heads. I think he did have some angle plug factory heads.
@@hotrodray6802 yeah without the guys like the late Joe Sherman and people like Eric Weingartner and other shops who still build parts and test, we would never learn anything. Wonder how many time Joe Sherman didn’t get it right before he did. His small blocks were hitting just under 8k with his machine work, and well built stock and aftermarket parts, and heavily ported years cause of his research. One of his articles I think he used some afr heads. And this info in print is there forever. Thats why I bough the books of the testing!! I can go back a reference joe Sherman articles whenever. And now we can call up a shop like Eric’s and order heads that can make the massive power. Sometimes progress is ok! Never forget we didn’t have these heads back in the 80’s and 90’s.
Eric, you should reach out to Larry Lombardo. He worked and drove for Grumpy Jenkins in the 70's and is a Pro Stock World Champion. He had input on the 292 and Bowtie cylinder heads.
If im not mistaken the 492 casting with the 194 valves were in the later models. I believe they were discontinued in the early 90s. The original ones with 202 valves didn't come with all 3 accessory bolt holes
Throw those away in the garbage! Call up Summit and buy a pair of Trick Flow “camel humps”…..That would be the plan for me these days. I have a 70LT-1 Vette that runs 12’s with 492 heads on it…..Invested over $1200 into them. They have 5/16” stem 2.05/1.60 valves and struggle to flow over 230CFM @ 28” on a flow bench. I built a PAW 383 motor back in the 80’s that ran pretty good even though it had the 5.65 four hundred SBC rods….Went 13.50ET@109MPH in a 65 ElCamino.
This is why I’m here today “because when I was young” , I too know every sbc perf casting known to man over counter or not . Just pulled worked over 461x off 355 in light 70 nova that went 10.80 @ 121. Done in our machine shop in early 90s , it’s what I could afford
Similar cubes, similar head flow, similar compression, it will put out almost the same exact power no matter who makes it. Like you said, it's and air pump.
492 heads replaced the 186 from 1969 and 1970. The 1.94/1.5 valves are for the 300 HP engines. The 2.02/1/6 valves are for the 350/350 HP in the 1969 and 1970 Corvette.
If you were to port a cast iron head....for yourself...and to benefit the hot rodding world...say you could have someone scan the ports afterwards and sell the files so we could take the files to a CNC shop...there is a very affordable, HUGE, CHEAP, engine called the PSI 8.8L...complete cores sell for $1500-2000...it's a GenVII BBC like a Vortec 8.1 and there are basically no affordable aluminum casting available for those engines, Raylar heads are like $5000 a set, the 8.8 starts as a 535ci 4.350" bore and 4.5" stroke, the block is strong, they come turbocharged for power generation, they use LS7 rockers, they come with a very nice aluminum intake that uses an 87-92mm 4 bolt LS throttle body, they use LS ecu controls with 58x, LS coils, 8.1 style cams. I would really love to see an 8.8PSI test engine, if there is enough meat in the block it would be awesome to see one bored out to 4.4" for 547ci, apparently the heads han be ported to flow 300-330cfm intake, it would be very interesting to see if a relatively budget torque monster could be built for similar money to an LS build that make gobs of tq and 600-700hp. The dream would be if enough interest could be generated for a partnership to be formed and we could as a group have some budget aluminum heads for GenVII BBC made like the numerous budget SBC/LS/BBC/SBF heads out there using your port design. I feel that the PSI 8.8 could be a viable alternative to LS and expensive aftermarket BBC blocks. Josh's Engine Rehab has messed with the heads and has made some proven results, he is not an economical solution, he charges big money for everything he does, the way he talks in his video everything is ultra expensive so I think that is a reflection in the way charges customers. I think that you could find a lot of money of the table and find a reasonable middle ground where customers will be happy and you will be happy. The fact that huge corporations have bought up all the major race engine manufacturers and jacked the prices of aftermarket blocks through the roof to the point even things like factory LS and LT blocks are astronomical prices compared to a few years ago these PSI 8.8s are a very tempting solution, IMO. A guy could plug one of these engines in the place of an LS using all the computers, transmissions, sensors, injectors and everything makes them even more interesting all while having significantly more displacement and strength than any LS or 8.1 is even cooler. Other than the PSI 8.8 I think another opportunity is in the new 6.8/7.3 Godzilla, the new bare blocks are $1500(an LY6,LS3 or L8T is $2400+), brand new complete Godzilla heads are $630 assembled each, the Godzilla heads are also aluminum and have TONS of potential, you start with a 4.220" bore, they can take 0.030-0.060" over, there are aftermarket forged pistons and rods readily available, Callies is coming with stroker cranks 4.5-4.6", which means a 511-522ci stroker Godzilla is very possible, the heads support 750+ hp with porting n/a, Godzilla uses LS lifters, Holley Terminator X is already available. any modular bolt pattern transmission will work. Those are two avenues of opportunity I see with meat on the bone to make big power, with something that has a less saturated and overpriced market. I hope you will consider it.
Yes they were a production head. Probably the last production head. Some had angle plugs and some didnt. Some 202 and 160 valves and some with 194 and 150 valves. I have had several sets
I remember PAW. That's been a day or two ago. Aren't the 492 the same head as a 186 with just a different casting number? Isn't it crazy how shitty these heads flow, but they ran damn good on a 350. Even the older first generation double humps was on some damn quick cars.
This is going to be very cool i know way to many ls guys here is what's sad every block that i have bought the guy said i am selling it to do a ls swap on a older vehicle like wow ok well more blocks for me then just another thing to i haven't foudn a good 4 bolt main block yet most of them were 2 bolt mains dang it 1 was 4 bolt but broke 1 of the threaded holes to mount the front motor plate on my sprint car so darn. But yeah let's see how good that head does
On the topic of compression vrs flow. I would love to see a test to help quantify the difference. So a mule engine with two sets of heads. One set somewhat restrictive. Another good flowing set. Then try them both with say 12 to 1 compression. Then re test both sets again with a stack of head gaskets. Maybe two felpro with a copper in between and then we could see an example of airflow changes as well as compression changes. That would be eye opening.
@WeingartnerRacing That is true, a changed quench would contaminate the science to a degree. But I still believe it would have reasonable relevents. I didn't add a piston change instead of gaskets as it is a much larger ask to have to buy extra pistons as well. But that would be a more pure test.
Maybe I'm lost here but, I've never heard of a 492 with 1.94.1.5 valves, straight plugs and pressed studs! Everyone that I've ever seen and used were a 2.02/ 1.60 valve with screw in studs and angle plugs. Who am I to know but, you might have something rare here.
Very nice Eric, I think that this will be a great series.
You don't see many sets of 492 heads.
Yours are in nice shape.👍
Nice cutters.👍
Thanks for sharing.👍🇺🇸👍
Man that PAW catalog was awesome, brings back memories here too!
Performance Automotive Warehouse. My go-to until Jegs and Summit came along. JC Whitney had good prices on parts too. Yep, I am getting old but not slow, lol.
Loved PAW, built my first MoPar with stuff from there and "Direct Connection," since I worked at the local Chry-Ply dealership. Also built other makes, including Buick 455s with the selection of parts they carried, most shown in that giant catalog!! A friend (RIP) had some early DART heads that his uncle got on a crate 355, bought directly from Racing Head Service. His uncle was a truck driver and used to pass them in Tennessee and stop in. When he upgraded his '69 Camaro, he bought and hauled the long-block (with 280H Comp cam and the Dart heads) back to Georgia for installation. When my friend got the engine (the Camaro got totalled in a DUI-caused wreck), we tore it down and freshened it, with another dual-pattern (Extreme 4x4) Comp camshaft. The DART heads actually had "double humps" cast right in, like a stealth modification, but were clearly cast with the "DART" logo under the valve covers. I think they had 180-200cc runners, screw in studs, etc. and were HEAVY!
Going by memory, so take that for what it's worth. 492's came with various options; 1.94/1.50, 2.02/1.60, straight plug, angle plug, screw in studs or pressed in studs, all with different part numbers (same casting number though). Now, for making them go-fast, the over the counter 492's were referenced the Chevy Power book, where they recommended using a 2.4" cutter to unshroud the intake valve vs the 2.34" cutter from the factory. Also, but not stated in the Chevy Power book was the need to "blend" the bottom cut to the bowl with a 70 (75?) degree cutter to blend within a 1/16" or so to the 60 deg cut. When "stock" heads were required in stock and super stock, we could get the cutters to match the factory chatter so that they would still look stock to the tech officials (back before cc'ing the ports and "do whatever you want as long as the cc matches" rules came into effect). Obviously angle plugs were never on production cars, so we were limited there. This was an NHRA accepted replacement head for some engine combos.
The 292's would still outflow them and also lacked the exhaust crossover. If heavily ported, the 292's would crack too. They'd be fine for drag racing if welded back up, but wouldn't last in Cup/Grand National like that. If you compared the 492 and the 292, the 292 would flow more, but were more "fragile," at least in my experience in both drag racing and circle track racing at the time. The last set of 292's (drag racing) I owned were ported so much near the pushrod pinch that the slot was just left open, then a piece of sheet metal was brazed to the slot on the pushrod side and the port re-blended. Even with all of that work, they would still flow just under 300 cfm @ 28in Hg. Obviously much better heads are available today, but that's all we had back then.
This is a pretty cool project, no doubt about it!
Ah, the good old days... PAW was THE SHIT back then. 👏😎
Known as the industry bible!
I miss PAW
PAW!! I remember that company. They had a location in the neighborhood I grew up in. The catalog was an amazing compilation of goodies that was thick as an unabridged dictionary! I left more than a few paychecks with them, in exchange for toys, lovely toys that made good power happen.
Still have PAW catalog on my bookshelf. Wish they were still around
I had a 388 back in late 80s that made 580,590 horsepower with a set of angle plug double humps. McCormick engine's built that one for me. It had wolverine cam flat tappet solid lifter 1.6 rockers. About 550 intake lift and 570 exhaust. Cam was same as Elgin 2nd generation. Really good running small block. He ported the heads. 11.2 compression. I ran hooker super comp 1 7/8s header. It can be done but takes some work to get there. I appreciate your work and all you bring light for your viewers.
PAW catalog..... OMG... talk about old memories... i wish i kept those copies around....
I still have a PAW catalog from the 90's
The 492 heads were production, and could have either 2.02/1.60 or 1.94/1.50 valves with the pressed in studs and straight spark plugs like yours has. The 292 heads were the over the counter heads from Crower or Crane one or the other, and had the angle plug, screw in rocker studs, and 2.02/1.60 valves. These were the "turbo" heads.
Interesting to see the lower performance 492. I have a ported set that started out with factory guide plates and screw in studs along with the angle plugs. They run great on the 383 in my truck and were originally cast in 1975. I have a short video on them if anyone would like to see. Thanks for doing this series Eric!
Still have my 97 PAW catalog. It’s a great reference source! This is going to be an awesome series! Still a double hump fan- yes I know they suck compared to what is currently available.
Won a lot of races with a set of 62' 461x heads. Ran 462 , 291 and 461. Still have one 186 in the shed. Now everyone has vortec heads, including me.
Hey me to! single 186, i gave up finding a mate, its not worth it, the ebay heads are a better option. Just hang it on the wall for nostalgia.
Getting power out of stock type heads will always be cool! PAW was amazing, I miss it. That was a lot of material on that valve job, looking forward to seeing the numbers after the blend.
You just messed up. 😂 you thought you got a lot of phone calls asking about porting cast iron before 💀. Love your videos
😂
Man I remember porting a set of 291’s back in 84’! They were 1.94/1.5 but they turned out really nice, and made good power.
Oh and the PAW catalog was the Bible of speed parts!
PAW !! I bought a "3/4" race cam from PAW for a 1971 400 small block that I bought for $25 in 1979. Went into a 72 SS Camaro that I bought (for $500) with a blown engine. Installed it with the 350s intake/carb and headers......fired it up and it vibrated horribly !!!
1979 I learned a valuable lesson about sbc 400s. $90 flywheel and this thing ran hard!
Wow, those heads are mint, nothing has been planed off them yet, the angles coolant holes haven't been exposed.
Love the old stuff
This will be interesting, looking forward to more.
PAW catalog! Think I still have a few of them in my Connex! Love those!
I ran a set of 492s on my first 383 back in 1992. Not a bad head for factory iron stuff
Thank you for your knowledge and videos
492's can kick ass. The ones I have done were as thick as bowtie castings. They will impress! Love this.
Try David Vizards porting on his 562 hp. Small Block video, I did it for my truck pulling guys with great results , mine were 461 castings, Im this gals hubby, I called you about a spacer several months ago, i must say you sounded like a real gentalman.May come see you some day.Keep up the great work.And... Been waiting for someone to do these early cast heads,
I have always loved SBC engines, with that said the chevy small block has a distributor and oil pump that runs perpetual to the crankshaft. That in itself is a big hurdle to cross. Then the LS is a skirted block and has 6 bolts per main cap. Will be far more reliable with increased hp. So flow all you want, take a SBC and an LS of a certain size and the LS should prevail. Plus how many of these heads do you think are available 💁♂️
Eric, I still have a carbide radius to angle cutter to duplicate the chamber unshrouding on the factory production 2.02 heads.
I've also seen a set of 492 straight plug heads that were the crane cams ported version, IIRC they called them "fireball" heads.
Converted many sets of factory castings to the HP factory style, ie: screw in studs, guide plates, convert to 2.02 & 1.6 valves.
I recall an article complete with dyno testing, on a 355ci, 600hp circle track SBC build that used ported 292 turbo heads. This was way before anyone openly discussed air flow in CFM and likely predates any commercially available flow benches. I'd like to see what a set of nearly 300 CFM factory turbo castings look like. I recall a lot of crack related issues with them even in unported condition.
Just for the record. The 492 heads on my small block are screw in studs and angle plug. I have never removed them from my engine to see valve size but they're working great and daily driven!
Mr Castiron, Breaking the inner web lol Thanks Eric Crane Fireball 292 ?
Yeah, the Crane 292s were the best thing going back in the day, The Reluctant Gearhead goes over them quite a bit.
PAW closed down in 2011, turned in to Vintage Speed equipment , mostly Flat head and old G1 Hemi parts. I'm too young to have ever bought anything from the catalog, but I do have a few copies of the older catalog,
I ran mildly cleaned up 492’s on a 1995 short block w/ 214/224 cam, th350 w/3200 converter and 3.42 gears. 1985 S10 Blazer
Ancient BFG DR’s
100 shot went 7.90’s 1/8th first time out. Decent for a DD
Had a 68 Impala factory 327 375 HP 400 Turbo transmission, 12 bolt posi.... Custom coupe ....had short top hideaway headlights..... Engine labeled on valve cover...Tanawanda Racing team.... chrome labels.... anyway had those same Head casting.....My Mother was rear-ended and totaled it I ran the engine and transmission and rear end in a 68 GMC short wide with leaf springs...I remember it well because I done a Valve job and cam replacement at low mileage ....had burnt valve....I put the same came as the 302 Duntov grind.....and accel distributor and wires.. around 1977....
These were a "service replacement" for all the "double hump" heads from about 1971 - on when machined for straight plugs and press in studs. They did have extra meat around the valve spring seats, and around the valve seats themselves, compared to earlier versions. These castings were also factory machined for angle plugs and screw in studs. Nice heads !
While I still have a huge soft spot for the original small block Chevy, I think the power production of a bone stock 4.8 or 5.3 LS shows that there is way more to horses than raw head flow #'s....
The combustion chambers in the base 706 heads are far more efficient than the camel humps, and add to that the directed swirl caractoristics of the LS heads. It makes a real difference.
That being said, I'd love to see an apples to apples comparison on same cubic inch engines using factory head castings and comparable cam specs. It would be interesting o see how much work it would take to get the factory small block heads to make as much HP as untouched base 706 heads. I have a really nice set of 461's that I may "fluff up" and throw on a 350 that I have just for some old school fun.
Those heads were available on production cars. 1970-1971 LT1 engines I think. Only the straight plug version. The 492 with angle plugs was gm parts counter only.
1969 L-46 186
1970 L-46 187
1969-1970 L-46 Replacement Engine 492
1970 LT-1 414
1970 LT-1 Replacement Engine 492
1971 LT-1 was a large chamber head to give 9.0:1 Comp with the new Flat Top Pistons (330 bhp gross).
492 were the 462 casting with accessory holes, there were the 292 angle pluggers, with 200 right at it cfm intake runners, for the street driver that head you have works great
Love stuff like this. Would love to see factory looking sbc when pop hood probably dual plane intake also. Make look close to factory as possible....
So you are, in fact, Superman. I knew all along. Your disguise didn't fool me.
Eric, I ordered a few parts of the PAW big thick blue book. Awesome. They sold headers and everything.
I’m old enough to remember my friend !
i have 406. 9:1,hyd roller street motor makes 585hp 547 tq at 6400rpm.has fully ported 292 heads.
Only 9:1 dam that’s pretty good .
The head you got was basically a 350/300 head that’s why no screw in studs and guide plates my 492 ‘s due have the 2.02/1.60 valve angle plugs and screw in studs with guide plates, this first series they tilted the plug up so flame travel went over the piston dome, then with the angle of the plug it was a great option over the stock head and still nhra compliance, the head like mine had the unshrouding in the combustion chamber so on 302 or 350 with 11 to one or greater pistons they worked very well
The 350/300 head is a #126 with the big 72cc chambers, these will have more compression than the 126.
Hard to believe that PAW went out of business in 2011. I figured they would have been around forever.
I still have a PAW catalog somewhere. It was like Christmas looking through that thing.
really looking forward to what kind of results you get
Whata cool idea for a video series!
I worked at PAW in the early 20s. Especially when they split the catalogs.
My dad had a set of those heads on his 67 Nova SS, L79. with a Duntov 030/30 camshaft. That thing was so docile under 2500 RPM, Get over that & it would unleash the Kraken, all the way to 6300 RPM. 4:11 gears with 60 series 14" wheels, and believe it or not, a close ratio saginaw 4 speed. First 3 gears sound/act like first gear.
The one & only time he took it to the strip, it turned a 13.20 at 110, if memory serves.
What double jumps with accessory holes was on the 70ish lt1. Had a buddy that bought a 74 Monte Carlo that had a lt1 with double humps but had bolt holes. Thanks for the content.
Find a 461 or better a 461x for flow testing; reputed to be at the top of the "double-humps"..Had a set of 461x heads that were ruined when a "reputable" engine machine company tried to install hard seats and cut into the water passages. The 492s shown here are late versions with threaded accessory mounts at the ends.
Still have my PAW catalogs and a bunch other vintage suppliers.
I’ve had great results from 186 heads
from experience u can build the hell out of a 202 head it cost me 3800 to build up a set but we ported every thing made them 204 and ported the intake ports and the intake to match the new ports plus we needed it to drop oil fast and more water for high rpms we even polished the block for oil drop with cast on cast way less head gasket problems i never lost the head gasket even over heating but i did twist a few crank off the front still running belts for the street
About 20 years ago i had a set of 492 heads with 202/160 valves on a 408 in a 68 Chevelle, i drilled the steam holes in them and it never ran over 210 degrees even when on it hard. It pushed around 480hp and was a hard pulling motor even bouncing on the rev limiter would still pin you to the seat. Wish i wouldnt have sold it now.
PAW HaHa! I built several of their kit engines back in the days before the internet. Fun times !!
i had 292 angle plug heads AND some 492 angle plugs. Bought from a circle track racer in the late 80's. Ran real strong, they were very heavily ported, but anyhow, my 492's were angle plug.
It would be nice to see what the head can do with the 1.94 valve and your port work because thats the most cost effective way to use a stock head.
P.A.W the dream book for 12 old kid back in the day.
I had a set I’d 292 turbo heads done by brandywine in Pa. Man that little 355 would run good
Yes, what you mentioned at the end has led to interesting results. Not many use the 706 heads because of low flow numbers. They have the 61cc chambers you can mill down to around 56cc or sometimes more. 2 tests from Holdener an another I saw found the 706 heads easily beat all other factory ls heads. Some of them by a lot. The extra flow never overcomes the compression you lose. So many people took off their 706 heads for other factory or even aftermarket heads the make a bunch less power. If I remember correctly the 2 casting numbers that have been touted as the ultimate factory heads for swaps actually came in absolutely last when actually tested due to big combustion chambers.
This is a short version so if you want more info search and it’s there. There are other tests too. I think this one is from when he worked for motortrend originally.
ua-cam.com/video/zfK45BqEo1Q/v-deo.htmlsi=xk4BMxqlhUQnG-_v
Paw haven't heard that name in ages!
I have a pair of 492's 2.02 screw in studs and angle plug I wonder why angle plug heads had the same casting #. Can't wait to see if they are worth using.
Watch out for castings with out accessory threads PAW story: PAW had random subcontractors grinding cranks. Subs pushed the steady rests in to hard so they could grind quicker with rough stones. You can guess what this did We reground lots of PAW cranks, some were so bad that they would not clean up at .040 Not a place to get shelf cams either.
These are the same heads that I put on my Camaro. That ran a little better than the 8.5 : 1 smog era heads.
The late Joe Sherman did many articles and builds in hot rod magazine.
He did high rpm crazy build!! He like the “turbo” heads or double hump heads.
I think he did have some angle plug factory heads.
Joe was a great guy and a performance guru. 👍👍👍
@@hotrodray6802 yeah without the guys like the late Joe Sherman and people like Eric Weingartner and other shops who still build parts and test, we would never learn anything.
Wonder how many time Joe Sherman didn’t get it right before he did. His small blocks were hitting just under 8k with his machine work, and well built stock and aftermarket parts, and heavily ported years cause of his research. One of his articles I think he used some afr heads.
And this info in print is there forever.
Thats why I bough the books of the testing!! I can go back a reference joe Sherman articles whenever.
And now we can call up a shop like Eric’s and order heads that can make the massive power. Sometimes progress is ok!
Never forget we didn’t have these heads back in the 80’s and 90’s.
Thank you for doing this and all your projects. What is the unshrouding clearance you like to see? On intake and exhaust valves.
JMO.
They were always radiused to the bore wall, then blended.
After 25 yrs I think it was .200 with a 1.94 and 1.6
Maybe, probably, sort of... Yep. 🤔
Still have a milk crate full of PAW catalogs too. Spent many hours looking through them.
I can remember mailing in. I think it was $15 to get the catalog. That is the PAW catalog. I think I'm gonna mail you. My. 043 bow tie heads to flow
Eric, you should reach out to Larry Lombardo. He worked and drove for Grumpy Jenkins in the 70's and is a Pro Stock World Champion. He had input on the 292 and Bowtie cylinder heads.
I remember PAW very well. They had just about anything you could imagine for sale. I put together one of their 383 kits for a friends truck.
If im not mistaken the 492 casting with the 194 valves were in the later models. I believe they were discontinued in the early 90s. The original ones with 202 valves didn't come with all 3 accessory bolt holes
Throw those away in the garbage! Call up Summit and buy a pair of Trick Flow “camel humps”…..That would be the plan for me these days. I have a 70LT-1 Vette that runs 12’s with 492 heads on it…..Invested over $1200 into them. They have 5/16” stem 2.05/1.60 valves and struggle to flow over 230CFM @ 28” on a flow bench. I built a PAW 383 motor back in the 80’s that ran pretty good even though it had the 5.65 four hundred SBC rods….Went 13.50ET@109MPH in a 65 ElCamino.
Very interesting project
This is why I’m here today “because when I was young” , I too know every sbc perf casting known to man over counter or not . Just pulled worked over 461x off 355 in light 70 nova that went 10.80 @ 121. Done in our machine shop in early 90s , it’s what I could afford
Similar cubes, similar head flow, similar compression, it will put out almost the same exact power no matter who makes it. Like you said, it's and air pump.
I Think these heads have a very thick deck, I milled my 461s .045 thou.,Had to correct intake port match.
Back in the day the "Cool Kids" had Crane 292 Turbo heads instead of Camel Humps...at least that's the The Reluctant Gearhead told me. 😂
I still have a p a w catalog from 2002... It really sucks they went out of business
492 heads replaced the 186 from 1969 and 1970. The 1.94/1.5 valves are for the 300 HP engines. The 2.02/1/6 valves are for the 350/350 HP in the 1969 and 1970 Corvette.
I still have a PAW catalog on my book shelf 😮😅😅
P A W, PERFORMANCE AUTOMOTIVE WHOLESALE, TAKING A TRIP ON THE WAYBACK MACHINE.
I like fun projects like this.
If you were to port a cast iron head....for yourself...and to benefit the hot rodding world...say you could have someone scan the ports afterwards and sell the files so we could take the files to a CNC shop...there is a very affordable, HUGE, CHEAP, engine called the PSI 8.8L...complete cores sell for $1500-2000...it's a GenVII BBC like a Vortec 8.1 and there are basically no affordable aluminum casting available for those engines, Raylar heads are like $5000 a set, the 8.8 starts as a 535ci 4.350" bore and 4.5" stroke, the block is strong, they come turbocharged for power generation, they use LS7 rockers, they come with a very nice aluminum intake that uses an 87-92mm 4 bolt LS throttle body, they use LS ecu controls with 58x, LS coils, 8.1 style cams. I would really love to see an 8.8PSI test engine, if there is enough meat in the block it would be awesome to see one bored out to 4.4" for 547ci, apparently the heads han be ported to flow 300-330cfm intake, it would be very interesting to see if a relatively budget torque monster could be built for similar money to an LS build that make gobs of tq and 600-700hp. The dream would be if enough interest could be generated for a partnership to be formed and we could as a group have some budget aluminum heads for GenVII BBC made like the numerous budget SBC/LS/BBC/SBF heads out there using your port design. I feel that the PSI 8.8 could be a viable alternative to LS and expensive aftermarket BBC blocks. Josh's Engine Rehab has messed with the heads and has made some proven results, he is not an economical solution, he charges big money for everything he does, the way he talks in his video everything is ultra expensive so I think that is a reflection in the way charges customers. I think that you could find a lot of money of the table and find a reasonable middle ground where customers will be happy and you will be happy. The fact that huge corporations have bought up all the major race engine manufacturers and jacked the prices of aftermarket blocks through the roof to the point even things like factory LS and LT blocks are astronomical prices compared to a few years ago these PSI 8.8s are a very tempting solution, IMO. A guy could plug one of these engines in the place of an LS using all the computers, transmissions, sensors, injectors and everything makes them even more interesting all while having significantly more displacement and strength than any LS or 8.1 is even cooler. Other than the PSI 8.8 I think another opportunity is in the new 6.8/7.3 Godzilla, the new bare blocks are $1500(an LY6,LS3 or L8T is $2400+), brand new complete Godzilla heads are $630 assembled each, the Godzilla heads are also aluminum and have TONS of potential, you start with a 4.220" bore, they can take 0.030-0.060" over, there are aftermarket forged pistons and rods readily available, Callies is coming with stroker cranks 4.5-4.6", which means a 511-522ci stroker Godzilla is very possible, the heads support 750+ hp with porting n/a, Godzilla uses LS lifters, Holley Terminator X is already available. any modular bolt pattern transmission will work. Those are two avenues of opportunity I see with meat on the bone to make big power, with something that has a less saturated and overpriced market. I hope you will consider it.
Is that a modern/late model tall deck with big cubic inch and small valve swirlport heads ? they were an option in some 5 ton truck ?
PAW catalog was better than the Sears and Roebuck Christmas toy catalog
Twice as many pages, too.
I REMBER THE 461 461 THE 186 AND THE 041 HEADS
462
186 casting was camel hump with bolt holes. Came on 68-69 350. Identical to those heads.
Similar but not the same. 492 was the best pre 292 head.
PAW!!! Miss those adds. Had a catalog somewhere!!
I hope you test the new sbc dyno engine with regular heads and an average cam like a comp 280 with .480 lift. The old school single pattern cams.
Yes they were a production head. Probably the last production head. Some had angle plugs and some didnt. Some 202 and 160 valves and some with 194 and 150 valves. I have had several sets
I remember PAW. That's been a day or two ago. Aren't the 492 the same head as a 186 with just a different casting number?
Isn't it crazy how shitty these heads flow, but they ran damn good on a 350. Even the older first generation double humps was on some damn quick cars.
I was just talking about PAW to a youngster that never knew what hotrodding was like pre-internet.
Next do some vortec heads!! Power is all over the map with those too!
I got (2) sets of 492's double hump . angle plug, 202 Intake -160 exhaust, screw-in studs
This is going to be very cool i know way to many ls guys here is what's sad every block that i have bought the guy said i am selling it to do a ls swap on a older vehicle like wow ok well more blocks for me then just another thing to i haven't foudn a good 4 bolt main block yet most of them were 2 bolt mains dang it 1 was 4 bolt but broke 1 of the threaded holes to mount the front motor plate on my sprint car so darn. But yeah let's see how good that head does
PAW book was thick like an LA phone book. CDW too!!
On the topic of compression vrs flow.
I would love to see a test to help quantify the difference. So a mule engine with two sets of heads. One set somewhat restrictive. Another good flowing set. Then try them both with say 12 to 1 compression. Then re test both sets again with a stack of head gaskets. Maybe two felpro with a copper in between and then we could see an example of airflow changes as well as compression changes. That would be eye opening.
That changes quench too. So two changes not one. Not very useful
@WeingartnerRacing
That is true, a changed quench would contaminate the science to a degree. But I still believe it would have reasonable relevents. I didn't add a piston change instead of gaskets as it is a much larger ask to have to buy extra pistons as well. But that would be a more pure test.
We had 2 sets and still have one set of 492s angle plug heads. One has 205s the other had 202s
Awesome video!!! But a 383 is closer to the 6.2L/376 cubes.
Maybe I'm lost here but, I've never heard of a 492 with 1.94.1.5 valves, straight plugs and pressed studs! Everyone that I've ever seen and used were a 2.02/ 1.60 valve with screw in studs and angle plugs. Who am I to know but, you might have something rare here.
PAW did have a set like you said 2.02 x 1.6 used them in 2 bbl oval track engines