1971 SBC 400 Versus 1967 BBC 396 Stock rebuilt , with cam and intake upgrade .

hey friends this is Nick and uh I call my channel DZ performance I Dino test and drag race and uh I share the videos with you guys and I appreciate everybody out there that's uh watching but what I'm bringing you today is I uh I have been working on designing custom carburetor spacers and I don't usually Dino test anything Street strip big block Chevys that are under 500 horse but today I got two of them that are just basic rebuild motors they you know they're not Optimum quench they're not fully balanced and blueprinted they are just Rebuilder Motors the first one I've got here on my right is a 396 325 horse 67 396 big block Chevy and then beside it is a 1971 400 small block and it was a two barrel it has a four barrel intake on it now and the re basic r-ring cleanup job that I did on these is Rings bearings uh freeze plugs cam bearings and um lap the valves in the the heads have both been rebuilt at a previous Point both motors have been bored and rebuilt uh sometime in the 9s is what the you know the indications that I got but what I'm going to show you is I'm going to show you some dino test and um engine startup stand time on these they are completely different Motors so it's not like an AB comparison you know the the 396 is 10 and A4 compression it has a hydraulic roller cam that's a 236 242 at 50,000 extreme energy uh very popular cam the uh small block is a 224 at 230 hydraulic flat ta it which I don't usually recommend flat taets the only time I'll put one in is a temporary type situation they just don't live long it doesn't matter what zinc or what you do they just the flat taets these days do not last so um anyway I'm going to show you some startup stand and some dyo time I'll come back and show you the the sheets and go over exactly the cam specs and some of the specs on the motors um I'll also list that information in the uh on the video so I'll roll some some dino time and uh some information about these thanks for [Music] watching d [Music] much [Music] care got [Music] okay this is what uh the best pull that the the 396 which is it's board 60 over so it's a 408 it did 446 horsepower and 465 ft-lbs of torque the the only the performance modifications in the motor is basic bow blend uh gasket match on the heads you know basically 1 hour of porting per head and the uh the the hydraulic roller cam and it's an edel Brock RPM intake it was dinot tested with a 770 uh brawler carburetor is a vacuum opening secondary carburetor but we had the secondaries tied open and I said I would go over the cam specs with you which you could look them up but I'll tell you what they are it's an advertised duration of 288 on the intake and 294 4 on the exhaust at measured at 50,000 it's 236 on the intake and 224 on the exhaust it's a valve lift of a 520 intake and a 540 on the exhaust with a lobe separation angle of 110 now the small block the reason I believe this motor Peaks so low I'm looking at it I think it peaked at 4500 RPMs approximately is these two barrel heads and I didn't even uh spend the time to paint them they've got a coded WD40 on them they they'll probably be taken off by the next owner or you know myself I don't know but I I've never Dino tested on two barrel heads that's that's a 150 exhaust valve and the intake valve I believe is a 172 I did invest the time of gasket matching and bow blending the the the heads with a little bit of porting work which was U you know on these heads was probably only a couple horses not much but it made 335 horsepower and 430 ft-lbs of torque I uh I'm anxious to change the heads on this motor and take another shot at it I think some good heads could really pick this thing up a bunch I I don't know exactly how much well I said I'd tell you the exact cam specs so I'll read them out to you it's a 268 on the intake it's a 280 on the exhaust at measured at 50,000 it's a 224 on the intake and 230 on the exhaust intake lift is 477 the exhaust lift is 480 lobe separation 110 and like I said it's a hydraulic flat tap at cam so uh that that was uh that was the numbers the the motors are completely different because this small block you're looking at is 8.4 to1 compression it's got dish Pistons it's you know going into that small area so the compression ratio was cut the the big block is a 1967 short block with 1969 heads on it and it it's got 10 10.2 compression big difference big Improvement but um in my next testing I'm going to take the small block and try to pick it up and give it some ad give it more of a Level Playing Field against the big block and see what better heads would do on it and then eventually uh upgrade it to the same cam but that was uh my 400 small block versus my 400 big block just Rebuilder series that that I did this last month but thanks for watching this is Nick

Channel: DZ Performance

Views: 82,401

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Id: 8xlHkOXp8TQ

Length: 10min 55sec (655 seconds)

Published: Tue Dec 26 2023