I pulled the 400 out of my old Blazer 35 years ago and put in a 396 bored .060. The machinist that did the work asked me if I thought the big block really was that more powerful as the 2 engines are so similar in bore and stroke and total displacement. Well, the big block has much longer intake runners that give it more torque, the reason big blocks are so streetable and also the big block has way more air flow, so more horse power. I'm guessing a stock 400 small block has about 175cfm max air flow on the intake and a stock oval port 396 from 67-69 has 260ish? If you're a head porter chime in but I think this is probably close. So the gains in power are to be expected. But a small block 400 with a set of Trick Flow or AFR heads is a very impressive engine indeed!
Id get the 400SB to equal compression as the 396. Or close to 10 to 1. Up the cams more equal too. 1.94/1.50 valves are good street heads. I bet a set of vortec would out do the 396 power. If u tested a low compression 8.5 smogger 402 of 71 or 72 the numbers would be alot less. 402s or 396s are very expensive to build, and hard to raise the compression without the older 396 heads which are hard to find. 400 small blocks have the advantages in everyway over the big block as so much more u can do to it and cheaper. 402s never did impress me. I love the torque down low of the 400s small blocks.
I'd like to see another test with these engines (or equivalent) each with AFR heads, maybe 210s or 220s for the sbc 400 and 265s on the 396, similar cam profiles, Performer RPMs on each and same carburetor. That would be fascinating to me.
thank you for this, been interested in seeing a sbc 400 vs bbc 396.......being they are within 1% difference of displacement of each other. Both have advantages over the other. But I was disappointed in the sbc 400's numbers, expected more....but then I realized that I was thought I read VORTEC, not versus.........the older heads are holding it back, would be nice to see what simply changing to vortec heads would do. Having the same grind for the cam in both would level the playing field a lot, but just a vortec head swap could probably intimidate that 396. thanks for the video!
Thanks for watching in the next couple weeks. I'm going to get a good set of factory Double hump heads On the 400 ,go back to the Dyno. To see what the difference will be , after that I will upgrade cam,
Nice. I'm doing a 400 sbc. build for a street rod. I'm using aluminum Speedway DH heads. Cam is an old Weiand Xcelerator #8102 to go with the old Xcelerator intake. I'd like to see the results with the head swap. Actually the 400 small block did quite well considering a factory 396 HP ratings from the factory with a single four barrel was 325 HP to 375 HP.
That would be the logical answer,, But I'm having a hard time finding vortex Heads cheap,, I've got some 1969 double humps. I'm going to try on the small block,
@@dzperformance7360 74 first year u could get the factory 400s with 4 barrel. 1970 only was the only year of the 598 heads on the 400s that use the 1.94/1.6 valves. 77 to 80 the 400s use the 1.72/1.5 valve 642 heads.
There is some truth to it because the large bores were pushing the limits for the small block size. That's why cooling was more of a challenge than with 350s and smaller. Head gaskets were a challenge because of poorer water circulation, again because the cylinders were almost too big for the small block size. That and the bigger heads are why going to a 396 big block is a good idea. But there are fixes for the 400 SB that get around those limitations, which is why they're still a good option.
I built a 400 SBC for my ‘71 Camaro when I was 18. That engine had so much torque and power. I’d rather the 400, you save a couple hundred lbs probably but you don’t lose the power.
@@percydofoygubrown953I agree 100%. Guys that say stuff like "sbc is lighter and dont loose power" have NEVER had a big block chevy done right. A stout 454 will always be a night and day difference than a stout 400 at the drag strip period
I had a 396 and 400 sitting in my garage.I chose the 400 no question.The 396 would win because of the head flow.I decided to go 400 for weight with aluminum heads and if you build these little dinosaur motors,OMG they are still a threat on the street.Bolted some AFR heads on this 406 sbc and off I went.Putting N/A LS motor behind me.The torque is insane.Great video thanks a bunch.
I've always been wary of siamese cylinder walls. I was warned against them as an up and coming technician. They're fine for the application they were meant for, light and medium duty trucks. I'd go 396 every time if I was building a street/strip engine. IMHO
Thanks for sharing. I own both. A stock 1975 2 bolt main 400 sb and a 1968 396 bb bored 30 over 750 double pumper almost complete. Looking forward to my tests. Very helpful, thanks again. Truck Driver Ray
For the ones that don't know, the 400 Chevrolet is are actually 401 cubic inches. The biggest difference that I am aware of are the 350 Pontiac's that are actually 354 cubic inches.
🐶😎🐶👍 and android your video thank you new subscriber once a Chevy man always a Chevy man hope to be in the market for 555 in.³ big block air in the near future stuff in a little two door 4 x 4 Jimmy boys and their toys
Thank you for the video With that SBC ,if compression could be in the mid to upper 9's with a set of lightly cleaned vortec heads , I bet it wakes up a bunch , I have a stroker 383 with a mild cam and it has over 400 Lbft at 2500, 480 @3500 and around 420HP @5200 rpm , using a Quadrajet carb and a Edelbrock performer manifold. and vortec heads.
Both numbers were slightly higher than i expected with such mild internals. Everybody loves Chevrolet and im not a hater i just like to be different. Thats why i love my Oldsmobile 455's. Ive done countless Olds big blocks. Most complete running cores are a dream to work on, never ever find a ridge in the bores no matter the mileage. The only surprises that sometimes come up is spun rod bearings on #7-#8. Other than that most crankshafts will pass for standard size bearings with a simple polish. For years ive designed my own custom camshafts from various cam grinders including, comp lunati and crane. Just doing bowl work and mild porting on stock cast heads, a healthy well thought out camshaft and stock high(er) compression cast pistons (1968-1970) and a single plane holley street dominator intake i can make an honest 510hp at 5900 and 515tq peaking around 4800. All this can often be done without having to visit a machine shop, as long as you check everything and pay attention to details. I have a handful of "tricks" that do help these numbers. The main point im trying to make is that a person can still build a decent 500hp engine with very little overall cost, and i think that would appeal to alot of people out there.
Great info. Thank you for putting this video out. I'm sure with the comp cam xr276hr and a good set of aluminum heads, the 400 sbc would pick up a lot. Again, thank you.
We built a blueprint 406 and it has iron eagle heads flowed and ported polish roller cam lifters makes serious power out of a small block in a 66 chevy 2 fun car
Hi, just heard of your channel from Eric W. I really like the content around streetable BBC & SBC motors. I used a 396 (408) 2 bolt main steel Chevy crank eagle 6.8 rods , home ported rectangular port heads with an 8:71 blower in 1996 - 99 , alcohol injected in a rearend dragster for bracket racing. 7:10 at 197 best Now 71 yrs old I have 2- 408 BBC with 781 heads planning on building for my daily driver truck.😊
Thanks for watching !! I've got some classic casting # 186 double humps. That's a 1969 Z28 or used on 350/350hp engine's, Those Head are going to raise the compression and also get a bunch more flow, Next month we'll see what they will do
Pending cylinder wall thickness the 400sbc might be at its limit . Standard rotating assembly and heads are not suitable for performance . . The sbc is really only to be considered a good runner .
@@dzperformance7360 yeah they are huge, my buddies 454 was dynoed with 2 1/4” shop dyno headers then put on his 1 7/8 headers and it picked up 50 ft lb and hp!
On the small block I think you could wake it up with some quality heads that have more compression and larger valves. You should probably get some 64cc chambers and 195 cc intake runners, and 2.02/1.65 valves. You need some runner volume to fill your cylinders. Could even go bigger runner if all you want is peak power. Might be able to go smaller chamber but that would require plugging in to a compression calculator to get your dynamic and make sure you won't detonate it to death. Too bad the pistons are dish, they don't quench as well as flat tops or d dish. To maximize quench try to get your head gasket thickness down.
Interesting- that small block with comparable internals and better flowing cylinder heads as the big block would probably put up similar numbers as the big block did.
the flat tappets and hydraulic stuff doesn't last anywhere near as long as it used to the manufacturers are building junk and getting away with it cause most of the competition is gone !
Interesting comparison here . Just from my own experience,I built a 408 cubic inch “ Lunati cams “ crate engine build over 30 years ago now , and with a flat tappet .488” lift cam at 236 degrees duration (@.050”) on 108 lobe separation angle along with 202/194 valves and port matched Very old School Edelbrock “ C3-B “ dual plane intake , 750 CFM Vacuum secondary Holley carb & 1-3/4” Mr.Gasket full length headers for a 1972 GMC Jimmy I owned , it made over 475 hp and over 545 lb-ft of torque and moved that rig pretty Damn well on a 4” lift 3:73 gears & 35” tires back in the day . I kept compression ratio at 9.5:1 for pump gas friendly use ( premium was LOTS less expensive then) and had a ball with it . To this day I still regret selling it shortly after buying my ‘02 GMC Sierra 2500 Crew Cab LB-7 Diesel , but family obligations deemed it necessary, and Now my Diesel makes WAY MORE H.P. & torque from 406 C.I. than that gasser ever did , plus it consistently gets over 18-21 mpg out on open highway on 8” lift & 37” tires !! Thanks for a great trip down memory lane here with your video . I’m sure you will find plenty more HP & Torque with larger valves & better flowing heads on the small block . Happy 2024 😎👍
@@shootermcgavin2819 I had some old Iron Stock 70 cc chamber heads that An employee of Don’s Speed Shop here in San Diego ported & polished and flow tested & equalized . He made exhaust ports like Brodix Aluminum casting “ Raised D port “ style & port matched my Old Edelbrock intake Manifold also for little to no mis- match at intake ports. Silicone -Bronze guides were installed along with Manley stainless steel valves & screw in 3/8” studs & pushrod guide plates installed . We used Comp-Cams Single coil “ Beehive “ style springs & 3/8” diameter chromolly pushrods & he set spring height up for no coil bind for over .500” lift at valves . If memory serves me correct I think he said they were at 120 lbs seat pressure and around 450 at max lift . Since I used a Lunati Camshaft in engine we consulted them for recommendations on set up for cam I used . A Pete Jackson “ Dual idler “ Cam drive setup was used as were Comp Cams 1.5 ratio roller rocker arms to finish off valve train setup . With flat top 4.165” bore ( .040” over stock) pistons it calculated out to 9.75:1 compression ratio ( give or take a 1/2 point ) with .030” thick head gaskets from Felpro. Hopefully this answers some of your questions, and by the way it wasn’t cheap , even by 1988 prices …..🥴. But man did it run ..👍
With the bore and stroke pretty close on both these engines, would be cool to see the head flow ,cam and compression a little closer. I would assume the numbers would almost be identical either way (if you detuned the 396 or upgraded the 400).
Hey nick I have a big block with afr 265 heads it has a hydraulic roller in it now but I want to change the cam to a solid roller have you ever did a cam swap without changing the springs the hydraulic springs are good to 725 lift the cam I'm swapping is only 666 lift thanks for any info
You need to get the proper solid roller spring. Its not so much lift its the seat/open pressures that change. Dont reuse those on the solid. Call a reputable cam co to get the right ones.
Thanks nick there was a video awhile back a guy did it with the same heads he was told to use a certain retainer and keepers buy the cam company ill just try by calling comp cams thanks for your help
I suspect the SBC will out-perform the BBC if you put better heads on it - reason being is because the piston speed is going to be quite a bit higher in the SBC due to the higher connecting rod ratio. The result will be a much higher velocity intake charge.
Keep us posted on the 400 SBC. Recently dropped a fresh rebuild (406) into my Chevelle and I'm fairly satisfied to this point. Always room for upgrades, though. Anxious to see what the new heads will do for yours. Thanks for sharing!
I have a 406 sbc with all the goodies.When I ran it back in the day it was a beast even with the hump heads.When I changed to AFR 195 holly crap.It was night and day.
I think the 400 needs 6 inch rods with custom pistons, definitely aluminum with some bigger valves and more compression. The splayed valves of the big block are a slight advantage though, but you can't ignore the overall weight of of an engine also.
400 small block stock hyd cam makes 330 HP and 430 lb ft is pretty good considering the 8.4:1 compression ratio. This is what made these engines so desirable (to me at least) the seat of the pants feeling when you tromp the go pedal! But then you end up with a single black mark until you let off it ! I'd love to build another engine (I have a virgin 400 block) . I built a 383 in the past because I had a 4 bolt 350 block. My idea for a 400 is to build the bottom similar to the 383 but with lower compression pistons. A hydraulic roller cam that concentrates on off idle to peak. Cruising, all you have to do is tickle the throttle and away you go ! Love the small block Chevy 400 build Dynos especially for a street style engine !
1969 ,cast# 290, comp cam' s 924-16 springs, Springs are shimmed to 125lbs on seat, new 2.07 / 1.72 stock valves, Minor bowl clean up and gasket match porting, Single angle vale job, Heads were rebuilt and came with the motor I just changed springs and clean The ports up a little bit, Thanks for watching.
I built a 406 small block, good heads, roller cam and good compression. 600 hp, ran 10's in a 3600 lb Impala. I am upgrading to a 8-71 and a LS firing order high lift roller cam. I hope to get 850 to 900hp at the tires.
had the chance to witness the result of a bone stock 1971 400 being fitted with a mid 60s Winters intake and probably a 650 Holley with a set of headers absolutely blow away off the line a very healthy Mopar 360 and that was with a TH400 and 2:93 ratio
Hey good to hear from you!!! You always put down positive comments on my Low quality backwoods videos appreciate it!!! In my racing experience, I've used cheap headers on a lot of 10 second cars. I don't really think you'll hurt it much,, Just my opinion.
@@dzperformance7360 I've cut a few of the smaller valve 882 heads out to 2.02/1.60 without issue. I believe they flow 205 cfm on the intake in that configuration without porting. That's second hand data though.
@dzperformance7360 love the channel I'll be waiting for this video. This kind of content is nice for guys like me who live for this kind of stuff. Keep it coming.
Them 5.565 rods don't make that much difference as u think. They help but not as much as people claim. I'm going run the 5.7 rods on my next 400. 6.0" rods get expensive and not many pistons choices.
@@jessesyfie7244 i guarantee they make a colossal difference ive turned 3 sets into horseshoes windowed two of the 3 blocks so yeah i put 5.7 rods in the one i didnt window and its still alive 26 years later used 6 inch rods in every other motor why do you suppose theres so many low deck 426 mopars out there using a rod about the same exact difference in length cause it squares the rotatioal force and doesnt put stress on the outside wall and go from the outside wall to the rod bolts . they make a lot more difference than you could ever imagine
@@dzperformance7360try this get 3 sets of rods a 5.56 a 5.7 and a 6 inch i already know the end result but ill let you do it so you cant say its not making much difference all floating pins so you can use the same piston with all rods take an old style torque wrench with the gage you can see turn the motor over this is rotational force and directly effects both hp and torque measure each set of pistons one ft lb of difference = roughly 30 hp the longer the rod the longer the lever you are using to turn the motor over thus less static rotational force there is a point the rod can be too long but definitely not with any factory sb chevy or oldsmobile rods when i built my first 6 inch rod motor i used oldsmobile rods and never went back to a 5.7 knowing what i found out
@@stevenbean9706 I havnt messed with rods much but the .020 over pistons I wanta run for my compression arnt available anymore for the 5.565 rods but are for the 5.7 rods which is better anyway so I'm going go with them. The 6.0 inch rod pistons u don't got many pistons choices plus then I'd have buy some 6.0 rods, just more money. I can grab some 5.7 rods from one of my 350s
I've used them in street strip cars many times and never had a problem,, But the more that theory is spread around the more cheap 400 small blocks for me
What made me impressed with that 396 was there was no really trick Parts no low tension Rings, lightweight pistons, professional balancing or blueprinting, none of that!! it was all just stock Rebuilder with a cam, intake and clean the heads up
What would be fun with that little 396/408ci is put it in a 69 Camaro with a 4-speed and 4.11 gear it could run High 11s and idles fairly smooth and would be excellent driving manners
Yes you are correct,, But Both motors are only stock rebuilds with cam , intake,carb Upgrades, 1971 sbc 400 was rated @ 265hp/400tq. Many people are forgetting that Those upgrades made + 70 horsepower and 30 lbs tq. All under four 4500 r p m. Would be a great setup to pull a trailer
@@dzperformance7360 Some decent heads, cam, intake, and exhaust will really wake up the 400 sb. They do make great torque. The 265 hp and 400-foot pounds were with a 2-barrel carburetor, so a 4-barrel is a great improvement when the rest of the induction and exhaust are upgraded. And you don't have to spin them very fast to get the good hp and tq numbers. Hope you tear back into it i will be watching for that video.
Throw together a nice set of closed small chamber heads and flat top pistons , 327 65/68cc heads 202 intake 194 exhaust and drill the steam holes and you'll have a nice running power house . 😊
Just dropped in an shp 406 in my 57 gasser. Even with smallish heads/carb and intake manifold it still lights up my 12 inch slicks.
I pulled the 400 out of my old Blazer 35 years ago and put in a 396 bored .060. The machinist that did the work asked me if I thought the big block really was that more powerful as the 2 engines are so similar in bore and stroke and total displacement. Well, the big block has much longer intake runners that give it more torque, the reason big blocks are so streetable and also the big block has way more air flow, so more horse power. I'm guessing a stock 400 small block has about 175cfm max air flow on the intake and a stock oval port 396 from 67-69 has 260ish? If you're a head porter chime in but I think this is probably close. So the gains in power are to be expected. But a small block 400 with a set of Trick Flow or AFR heads is a very impressive engine indeed!
I put vortecs on the last 400 that I had. It ran really good. Summit 1107 cam
It's pretty amazing to see these two engines side by side , it really shows the difference , very cool !
it really points out how important compression And cylinder head flow is, To a performance motor,
Id get the 400SB to equal compression as the 396. Or close to 10 to 1. Up the cams more equal too. 1.94/1.50 valves are good street heads. I bet a set of vortec would out do the 396 power. If u tested a low compression 8.5 smogger 402 of 71 or 72 the numbers would be alot less. 402s or 396s are very expensive to build, and hard to raise the compression without the older 396 heads which are hard to find. 400 small blocks have the advantages in everyway over the big block as so much more u can do to it and cheaper. 402s never did impress me. I love the torque down low of the 400s small blocks.
I'd like to see another test with these engines (or equivalent) each with AFR heads, maybe 210s or 220s for the sbc 400 and 265s on the 396, similar cam profiles, Performer RPMs on each and same carburetor. That would be fascinating to me.
thank you for this, been interested in seeing a sbc 400 vs bbc 396.......being they are within 1% difference of displacement of each other. Both have advantages over the other. But I was disappointed in the sbc 400's numbers, expected more....but then I realized that I was thought I read VORTEC, not versus.........the older heads are holding it back, would be nice to see what simply changing to vortec heads would do. Having the same grind for the cam in both would level the playing field a lot, but just a vortec head swap could probably intimidate that 396. thanks for the video!
Thanks for watching in the next couple weeks. I'm going to get a good set of factory Double hump heads On the 400 ,go back to the Dyno. To see what the difference will be , after that I will upgrade cam,
Did exactly that and made 428 hp and 525 lbs at 3500 rpm.Beat up on lots of big blocks and not a big cam at all!
@@dzperformance7360 vortec heads are overrated when swapping use something better.
Nice. I'm doing a 400 sbc. build for a street rod. I'm using aluminum Speedway DH heads. Cam is an old Weiand Xcelerator #8102 to go with the old Xcelerator intake. I'd like to see the results with the head swap. Actually the 400 small block did quite well considering a factory 396 HP ratings from the factory with a single four barrel was 325 HP to 375 HP.
Sounds like it's going to be a cool motor!! thanks for watching
That's a good point!!
Be interesting to see more comparisons with head and cam swaps on the lil 400.
I want to use a factory style head and get the compression and cam about the same size for a more direct comparison., Before I finish this project
The weight savings of the 400 is the main reason for choosing it.
It'd be easier for me to upgrade the smallblock so that's probably what i'm going to do
A set of vortech heads should wake up that small block and with more compression also...
That would be the logical answer,, But I'm having a hard time finding vortex Heads cheap,, I've got some 1969 double humps. I'm going to try on the small block,
@@dzperformance7360 Those are good heads, should make good power... Is the casting number 186?
yes
They're upgraded to 2.02/1.60 valve's
!.72 and 1.5 valves are not factory size valves, all 400's left the factory with 1.94 and 1.6 valves
The information i've seen is all of the 400 small blocks were two barrels up until 1974
And I've taken lots of 2 barrel heads off of 400 that appear to be stock.
Original?? But I could be incorrect
@@dzperformance7360 74 first year u could get the factory 400s with 4 barrel. 1970 only was the only year of the 598 heads on the 400s that use the 1.94/1.6 valves. 77 to 80 the 400s use the 1.72/1.5 valve 642 heads.
Could have got 40hp with a roller on the 400 alone.
Yes,,We're going to get there,,
Not really a fair shot for the 400sb
400sbc was low power junk headgasket nightmares overheating etc
Like fucking bullshit they were!
There is some truth to it because the large bores were pushing the limits for the small block size. That's why cooling was more of a challenge than with 350s and smaller. Head gaskets were a challenge because of poorer water circulation, again because the cylinders were almost too big for the small block size.
That and the bigger heads are why going to a 396 big block is a good idea. But there are fixes for the 400 SB that get around those limitations, which is why they're still a good option.
I'd take the 400 anyway of the week over a 396 ! Had one in my 46 Chevy coupe stock other than headers, she was Strong ! 👍
Yea I'm a big block guy. But the 400 did not get a fair shake. With good heads cam compression the 400 would be equal or better. I think.
Thanks for watching. I'll be sure to show you guys when I give the small block another shot
I built a 400 SBC for my ‘71 Camaro when I was 18. That engine had so much torque and power. I’d rather the 400, you save a couple hundred lbs probably but you don’t lose the power.
Can’t nothing beat a bbc if you do all the up grades to both engines bbc still on top…..
@@percydofoygubrown953I agree 100%. Guys that say stuff like "sbc is lighter and dont loose power" have NEVER had a big block chevy done right. A stout 454 will always be a night and day difference than a stout 400 at the drag strip period
@@percydofoygubrown953way more expensive too, I will keep my 400 small block over any expensive 396/402.
A set of 441 or 993 with a 1.94 valve and bowl blend and a good valve job that 400 would be around 450 easy...
I had a 396 and 400 sitting in my garage.I chose the 400 no question.The 396 would win because of the head flow.I decided to go 400 for weight with aluminum heads and if you build these little dinosaur motors,OMG they are still a threat on the street.Bolted some AFR heads on this 406 sbc and off I went.Putting N/A LS motor behind me.The torque is insane.Great video thanks a bunch.
Thanks for watching,, Cool story
396 all the way
I've always been wary of siamese cylinder walls. I was warned against them as an up and coming technician. They're fine for the application they were meant for, light and medium duty trucks.
I'd go 396 every time if I was building a street/strip engine. IMHO
Thanks for sharing. I own both. A stock 1975 2 bolt main 400 sb and a 1968 396 bb bored 30 over 750 double pumper almost complete. Looking forward to my tests. Very helpful, thanks again. Truck Driver Ray
For the ones that don't know, the 400 Chevrolet is are actually 401 cubic inches. The biggest difference that I am aware of are the 350 Pontiac's that are actually 354 cubic inches.
🐶😎🐶👍 and android your video thank you new subscriber once a Chevy man always a Chevy man hope to be in the market for 555 in.³ big block air in the near future stuff in a little two door 4 x 4 Jimmy boys and their toys
Thank you for the video
With that SBC ,if compression could be in the mid to upper 9's with a set of lightly cleaned vortec heads
, I bet it wakes up a bunch , I have a stroker 383 with a mild cam and it has over 400 Lbft at 2500, 480 @3500
and around 420HP @5200 rpm , using a Quadrajet carb and a Edelbrock performer manifold. and vortec heads.
Stock vortec heads would wake that 400 up.thanks for sharing.
Okay I'll try it,,, I got some 1969, cast #186 heads that i'm proud of I want to try those first but then I'll go for the vortex's
Both numbers were slightly higher than i expected with such mild internals. Everybody loves Chevrolet and im not a hater i just like to be different. Thats why i love my Oldsmobile 455's. Ive done countless Olds big blocks. Most complete running cores are a dream to work on, never ever find a ridge in the bores no matter the mileage. The only surprises that sometimes come up is spun rod bearings on #7-#8.
Other than that most crankshafts will pass for standard size bearings with a simple polish. For years ive designed my own custom camshafts from various cam grinders including, comp lunati and crane. Just doing bowl work and mild porting on stock cast heads, a healthy well thought out camshaft and stock high(er) compression cast pistons (1968-1970) and a single plane holley street dominator intake i can make an honest 510hp at 5900 and 515tq peaking around 4800. All this can often be done without having to visit a machine shop, as long as you check everything and pay attention to details. I have a handful of "tricks" that do help these numbers. The main point im trying to make is that a person can still build a decent 500hp engine with very little overall cost, and i think that would appeal to alot of people out there.
Olds lack head sealing. Not enough head bolts.
Great info. Thank you for putting this video out. I'm sure with the comp cam xr276hr and a good set of aluminum heads, the 400 sbc would pick up a lot. Again, thank you.
The 396 would have made more power if you revved it up some. Short stroke bbc’s will rev pretty good. You hamstrung it stopping at 5600 rpm.
We built a blueprint 406 and it has iron eagle heads flowed and ported polish roller cam lifters makes serious power out of a small block in a 66 chevy 2 fun car
Is that with the stock block or aftermarket? Thinking about doing the same thing to my gen 1 400 it’s all stock
Hi, just heard of your channel from Eric W.
I really like the content around streetable BBC & SBC motors.
I used a 396 (408) 2 bolt main steel Chevy crank eagle 6.8 rods , home ported rectangular port heads with an 8:71 blower in 1996 - 99 , alcohol injected in a rearend dragster for bracket racing. 7:10 at 197 best
Now 71 yrs old I have 2- 408 BBC with 781 heads planning on building for my daily driver truck.😊
6.8 rods are perfect
Enjoyed this. Look forward to the SB Head swap
Thanks for watching !! I've got some classic casting # 186 double humps. That's a 1969 Z28 or used on 350/350hp engine's, Those Head are going to raise the compression and also get a bunch more flow, Next month we'll see what they will do
202 heads big cam,and 850 dp,dfholly on the 400. Runs about 456 hp and 530 torque
=I wish you still had the motor is the 408 to big block Chevy would have made more horsepower than that in between 5500 and 6 Grand
Sounded llike the 400 didn't have enough timing and it wasn't reved very high.
Heads and low compression killed that small block bad!.
We're gonna fix that and retest to see what happens. Thanks for the comment, Thanks for watching
Pending cylinder wall thickness the 400sbc might be at its limit . Standard rotating assembly and heads are not suitable for performance . . The sbc is really only to be considered a good runner .
Apples to apples I'll take the 400 SBC all day long
Put a super charger on the 400 it's got low enough compression for it and do head work
All things equal the big block will always produce more power because the big block will have bigger valves.
Bigger valves does only make power at higher rpms. Kills torque at low rpms.
Both engines appeared to have giant big tube headers on the dyno! Cool vid, would love to see afr 220 heads and a hyd roller in that 400!
The headers are just the dyno shop's standard headers that they use on all the Engines.
@@dzperformance7360 yeah they are huge, my buddies 454 was dynoed with 2 1/4” shop dyno headers then put on his 1 7/8 headers and it picked up 50 ft lb and hp!
Nothing sounds better than a Chevy Big Block ! The small block set up would still be a good truck or RV engine, given the power low down ?
On the small block I think you could wake it up with some quality heads that have more compression and larger valves. You should probably get some 64cc chambers and 195 cc intake runners, and 2.02/1.65 valves. You need some runner volume to fill your cylinders. Could even go bigger runner if all you want is peak power. Might be able to go smaller chamber but that would require plugging in to a compression calculator to get your dynamic and make sure you won't detonate it to death. Too bad the pistons are dish, they don't quench as well as flat tops or d dish. To maximize quench try to get your head gasket thickness down.
Interesting- that small block with comparable internals and better flowing cylinder heads as the big block would probably put up similar numbers as the big block did.
the flat tappets and hydraulic stuff doesn't last anywhere near as long as it used to the manufacturers are building junk and getting away with it cause most of the competition is gone !
For the 400, the valves in the stock heads should have been 1.94 intake and 1.50 exhaust.
Thanks for discussing the camshafts!
Change the heads and put a 230/236 hydraulic roller in it.
I'm on it
Need do the tests with equal comparisons so to apples to apples. Id like to see how they both would compare to the LS 6.0 LQ9 engine as well.
ApPlEs To ApPlEs the big block would wipe the floor with the 6.0 .
Interesting comparison here . Just from my own experience,I built a 408 cubic inch “ Lunati cams “ crate engine build over 30 years ago now , and with a flat tappet .488” lift cam at 236 degrees duration (@.050”) on 108 lobe separation angle along with 202/194 valves and port matched Very old School Edelbrock “ C3-B “ dual plane intake , 750 CFM Vacuum secondary Holley carb & 1-3/4” Mr.Gasket full length headers for a 1972 GMC Jimmy I owned , it made over 475 hp and over 545 lb-ft of torque and moved that rig pretty Damn well on a 4” lift 3:73 gears & 35” tires back in the day . I kept compression ratio at 9.5:1 for pump gas friendly use ( premium was LOTS less expensive then) and had a ball with it . To this day I still regret selling it shortly after buying my ‘02 GMC Sierra 2500 Crew Cab LB-7 Diesel , but family obligations deemed it necessary, and Now my Diesel makes WAY MORE H.P. & torque from 406 C.I. than that gasser ever did , plus it consistently gets over 18-21 mpg out on open highway on 8” lift & 37” tires !! Thanks for a great trip down memory lane here with your video . I’m sure you will find plenty more HP & Torque with larger valves & better flowing heads on the small block . Happy 2024 😎👍
Mind describing the cylinder heads that were used?
@@shootermcgavin2819 I had some old Iron Stock 70 cc chamber heads that An employee of Don’s Speed Shop here in San Diego ported & polished and flow tested & equalized . He made exhaust ports like Brodix Aluminum casting “ Raised D port “ style & port matched my Old Edelbrock intake Manifold also for little to no mis- match at intake ports. Silicone -Bronze guides were installed along with Manley stainless steel valves & screw in 3/8” studs & pushrod guide plates installed . We used Comp-Cams Single coil “ Beehive “ style springs & 3/8” diameter chromolly pushrods & he set spring height up for no coil bind for over .500” lift at valves . If memory serves me correct I think he said they were at 120 lbs seat pressure and around 450 at max lift . Since I used a Lunati Camshaft in engine we consulted them for recommendations on set up for cam I used . A Pete Jackson “ Dual idler “ Cam drive setup was used as were Comp Cams 1.5 ratio roller rocker arms to finish off valve train setup . With flat top 4.165” bore ( .040” over stock) pistons it calculated out to 9.75:1 compression ratio ( give or take a 1/2 point ) with .030” thick head gaskets from Felpro. Hopefully this answers some of your questions, and by the way it wasn’t cheap , even by 1988 prices …..🥴. But man did it run ..👍
With the bore and stroke pretty close on both these engines, would be cool to see the head flow ,cam and compression a little closer. I would assume the numbers would almost be identical either way (if you detuned the 396 or upgraded the 400).
Thanks for watching. I'm going to tune them in closer To each other next month and retest the small block
Weight of the Crankshaft and the canted valves give the 396 the torque advantage. It also weighs a few more lbs but those wider valve covers.......
Try L98 heads on the 400. Compression should go up 2 points and weight reduction too
Hey nick I have a big block with afr 265 heads it has a hydraulic roller in it now but I want to change the cam to a solid roller have you ever did a cam swap without changing the springs the hydraulic springs are good to 725 lift the cam I'm swapping is only 666 lift thanks for any info
It's possible it could work in my opinion.You would need at least 175lbs of seat pressure and 385# open to make it work.
You need to get the proper solid roller spring. Its not so much lift its the seat/open pressures that change.
Dont reuse those on the solid. Call a reputable cam co to get the right ones.
Thanks nick there was a video awhile back a guy did it with the same heads he was told to use a certain retainer and keepers buy the cam company ill just try by calling comp cams thanks for your help
I seen a 406 put 1000hp to the wheels of a Camaro before.
he'll yaa
Those are the worst heads gm ever built. It will pick up 100hp with a set of vortec heads same cam
If you watch the next video on that four hundred small block I put one eighty six double humps on it and it picked it up 90 horses
No it wont! Vortecs arent as great as everyone makes them out to be.
Comparing apples and oranges
hey is that 400 sm has a 350 steel crank with 202 heads
I think a good set of heads will put the 400sb over 400hp.
I'm betting on 420 horsepower and 465 tq.
Sooo much goo on the china rainof that small block. Imagine the amount that squeezed into the engine!
Both great motors,dollar for dollar i think its the small block
@DZ Performance What do you want for the SB 400 I have Paypal !!!
$4950 today with Trick Flow heads, text me if interested, Nick 816 213 7204
Man are you in Houston tx
I suspect the SBC will out-perform the BBC if you put better heads on it - reason being is because the piston speed is going to be quite a bit higher in the SBC due to the higher connecting rod ratio. The result will be a much higher velocity intake charge.
Care to quantify 'out perform'? And explain how much of a difference intake velocity due to rod ratio makes?
Keep us posted on the 400 SBC. Recently dropped a fresh rebuild (406) into my Chevelle and I'm fairly satisfied to this point. Always room for upgrades, though. Anxious to see what the new heads will do for yours. Thanks for sharing!
I have a 406 sbc with all the goodies.When I ran it back in the day it was a beast even with the hump heads.When I changed to AFR 195 holly crap.It was night and day.
Heads will help, but compression has to be there in the base equation, and the one in vid does not have it at 8.5:1.
not apples to apples but I like the comparison. Dollar for dollar in aftermarket parts, I'd choose the mouse for power
You are correct, but a 4sp and a board out 396 With a rumbling cam in a Nova. Camaro or chavelle just looks bad ass
You wouldn’t wanna sell that 396 would you?
$4,800 And I deliver it For an extra $150 to $350, depending on where you're at in the U. S
Actual average cylinder pressure?
You might as well used a 305 HO
I'll do that next time
I think the 400 needs 6 inch rods with custom pistons, definitely aluminum with some bigger valves and more compression.
The splayed valves of the big block are a slight advantage though, but you can't ignore the overall weight of of an engine also.
Thanks for watching,, Stick with me. I'm gonna change some stuff and we'll make more horsepower in future test
400 small block stock hyd cam makes 330 HP and 430 lb ft is pretty good considering the 8.4:1 compression ratio.
This is what made these engines so desirable (to me at least) the seat of the pants feeling when you tromp the go pedal! But then you end up with a single black mark until you let off it !
I'd love to build another engine (I have a virgin 400 block) . I built a 383 in the past because I had a 4 bolt 350 block.
My idea for a 400 is to build the bottom similar to the 383 but with lower compression pistons. A hydraulic roller cam that concentrates on off idle to peak.
Cruising, all you have to do is tickle the throttle and away you go !
Love the small block Chevy 400 build Dynos especially for a street style engine !
Thanks Nick, love the dyno and build info! Any idea what heads are on the big block? Thanks.
1969 ,cast# 290, comp cam' s 924-16 springs, Springs are shimmed to 125lbs on seat, new 2.07 / 1.72 stock valves, Minor bowl clean up and gasket match porting, Single angle vale job, Heads were rebuilt and came with the motor I just changed springs and clean The ports up a little bit, Thanks for watching.
So sounds like you could do better on the big block for heads also
I’ve been building GMs for years and I can say with confidence If everything was truly equal the sb 400 would walk away from the 396.
Yes! I'd say the same think too!
Use the 400
Thanks for watching
There's no comparison. Yet. 👍
I built a 406 small block, good heads, roller cam and good compression. 600 hp, ran 10's in a 3600 lb Impala. I am upgrading to a 8-71 and a LS firing order high lift roller cam. I hope to get 850 to 900hp at the tires.
Should i take the 396 out of my 68 Chevelle and put in a 454? Any and all advice would be helpful.
Yeah probably so
Thanks for sharing
What heads are on the 396 ?
why was the pull limited to under 6k rpms?. i doubt anyone that has them motors will be pussy footing around at them rpm's.
Should have used a stock 69 396 2bl making 265 hp to be equal to the 400.
Great stuff!!!
That's a good idea,, Thanks for watching
what impressed me was the difference in torque being only 30 ft/lbs apart
Yes, that was a lot of torque for the small block. When it's nearly 2 points less compression,
had the chance to witness the result of a bone stock 1971 400 being fitted with a mid 60s Winters intake and probably a 650 Holley with a set of headers absolutely blow away off the line a very healthy Mopar 360 and that was with a TH400 and 2:93 ratio
Got a question for you. Will 1 3/4 headers kill alot of hp on a 550hp 496 vs 2 inch headers? Thanks
Hey good to hear from you!!! You always put down positive comments on my Low quality backwoods videos appreciate it!!! In my racing experience, I've used cheap headers on a lot of 10 second cars. I don't really think you'll hurt it much,, Just my opinion.
To give a more direct answer. I think those inch and 3/4 headers will be just fine. Work great on a 550 horse motor.
What's the casting # for the small valve head? Pretty good for a 1.72 valve.
882
@@dzperformance7360 those castings were available in 1.94/1.50 and 2.02/1.60 as well. I believe as cast they are 165 cc runner.
I think they were 165cc, I did not know you could get them from the factory 2.02/1.60
@@dzperformance7360 I've cut a few of the smaller valve 882 heads out to 2.02/1.60 without issue. I believe they flow 205 cfm on the intake in that configuration without porting. That's second hand data though.
That 400 would rock with good heads and a roller cam. I have the same set up.
I've improved it with some double hump heads and I'll have a video to you guys next week. Showing the improvement on the 400sdc
@dzperformance7360 love the channel I'll be waiting for this video. This kind of content is nice for guys like me who live for this kind of stuff. Keep it coming.
the 5.56 connecting rods in the 400 destroyed everything about it ! first thing i did was buy 6 inch steel rods it was the best investment ever !
This is the first time i've run the stock 5.56 rods, I know they're hurting power. But I wonder how much?,?
Them 5.565 rods don't make that much difference as u think. They help but not as much as people claim. I'm going run the 5.7 rods on my next 400. 6.0" rods get expensive and not many pistons choices.
@@jessesyfie7244 i guarantee they make a colossal difference ive turned 3 sets into horseshoes windowed two of the 3 blocks so
yeah i put 5.7 rods in the one i didnt window and its still alive 26 years later used 6 inch rods in every other motor why do you suppose theres so many low deck 426 mopars out there using a rod about the same exact difference in length cause it squares the rotatioal force and doesnt put stress on the outside wall and go from the outside wall to the rod bolts . they make a lot more difference than you could ever imagine
@@dzperformance7360try this get 3 sets of rods a 5.56 a 5.7 and a 6 inch i already know the end result but ill let you do it so you cant say its not making much difference all floating pins so you can use the same piston with all rods take an old style torque wrench with the gage you can see turn the motor over this is rotational force and directly effects both hp and torque measure each set of pistons one ft lb of difference = roughly 30 hp the longer the rod the longer the lever you are using to turn the motor over thus less static rotational force there is a point the rod can be too long but definitely not with any factory sb chevy or oldsmobile rods when i built my first 6 inch rod motor i used oldsmobile rods and never went back to a 5.7 knowing what i found out
@@stevenbean9706 I havnt messed with rods much but the .020 over pistons I wanta run for my compression arnt available anymore for the 5.565 rods but are for the 5.7 rods which is better anyway so I'm going go with them. The 6.0 inch rod pistons u don't got many pistons choices plus then I'd have buy some 6.0 rods, just more money. I can grab some 5.7 rods from one of my 350s
Merci !!!! Fun testing
Excellent comparison
Thanks for watching
400 sb are bored out to much they overheat I'll take the 300 hp 327 much better motor motor to abuse
Id take a 400SB way over any 327 for a truck towing engine just for the torque down low and the grunt!
@@jessesyfie7244 Crack up at the 327 comments. So what they can rev whoopee!
Cubes on teh st every time. 0 comparison between a mild 400 and 327.
I have been told the SBC 400s have overheating problems 😮
I've used them in street strip cars many times and never had a problem,, But the more that theory is spread around the more cheap 400 small blocks for me
400 only have over heating problems if you put heads on without the steam holes drilled. Other than that they run cool as ice 🧊
That's all bullshit and is fair from the truth!
@@jimreaume2937that's all bullshit and is from from the truth! No heating problems what so ever!
Your information that 400 SBs have heating problems is all bullshit!
I love your 55 Chevy!
Thanks!!! I was kind of showing it off as a backdrop
I'm not gunna lie Nick. That 396 didnt do bad at all. Those ft lbs were really good I thought! Those arent known for rocking the floor...
What made me impressed with that 396 was there was no really trick Parts no low tension Rings, lightweight pistons, professional balancing or blueprinting, none of that!! it was all just stock Rebuilder with a cam, intake and clean the heads up
What would be fun with that little 396/408ci is put it in a 69 Camaro with a 4-speed and 4.11 gear it could run High 11s and idles fairly smooth and would be excellent driving manners
Shows how not to build a 400 small block.
Yes you are correct,, But Both motors are only stock rebuilds with cam , intake,carb Upgrades, 1971 sbc 400 was rated @ 265hp/400tq. Many people are forgetting that Those upgrades made + 70 horsepower and 30 lbs tq. All under four 4500 r p m. Would be a great setup to pull a trailer
@@dzperformance7360 Some decent heads, cam, intake, and exhaust will really wake up the 400 sb. They do make great torque. The 265 hp and 400-foot pounds were with a 2-barrel carburetor, so a 4-barrel is a great improvement when the rest of the induction and exhaust are upgraded. And you don't have to spin them very fast to get the good hp and tq numbers. Hope you tear back into it i will be watching for that video.
Thanks for watching ,,thanks for your input!
A motor is a piece of electrical equipment..an engine is a gas combustion piece of equipment
The heads you used on the 400 are terrible.
Very true!! like I said they was not even worth painting
Isn't the best a 400 block with 327 crank for 355 with a 2-1 rod ratio?
Cool! Throw a 6.0 liter in the mix too, old vs new! Great video!
400 sbc probably has two barrel heads on it. Exactly that’s what happened.
I've got some 1969 double humps we're gonna try on the sbc,, Thanks for watching
Throw together a nice set of closed small chamber heads and flat top pistons , 327 65/68cc heads 202 intake 194 exhaust and drill the steam holes and you'll have a nice running power house . 😊
That's a great idea. I'm working on it. Thanks for watching.