SBC 408 cid, is 600 hp unreasonable N/A

[CamKing]

What RPM are you shifting at?
What RPM are you going thru the lights at?

[Strange Magic]

What would you recommend for pistons and rings? I should be in the neighborhood of 13:1 compression now.

I can't stress enough how important compression is in an engine. It is for that reason, although not the only reason, as to why many fall short of their expectations. The words "should be" or "I think" tell me that this is an area that someone did not take notes from proper findings. Concrete statements such as "my chamber is 58, my cubic inch is 408, my piston to deck is .005 and my gasket is 4.180 x .041 with a positive 4 cc dome" will indicate to me that someone has done there homework in an area that has a large impact on the outcome of an engine.

When building for drag, if that's what it is, you should highly take into consideration that if the application is on race fuel, than max out that compression for the given race fuel that you would have been on anyway. Sunoco blue or VP's C-14 will just about allow you to go to the max limits of what the engine can max yield for compression. In the case of this 408 sbc, I personally would have shot for 14.4-14.7 for a weekend bracket warrior. The power gains are huge if it's currently sitting at 12.8-13.0, and that's a big "if".

A simple .043, .043, 3mm with a vac pump will yield 45 to 55hp when the two are combined together, and that's with the same compression ratio as what you are running now. The gains are immense. We provide performance products into our builds in our shop and to the industry as well, everything from custom pistons, ring packages, wrist pins....ect.

Here is one that is in my shop right now. This picture was taken about 7:00 last night and I continued on with it port matching the super victor, washed it and installed it, and the valve covers and split the shop at 11pm last night. It is much the same as you are describing. This one is 3.750 stroke and a 4.060 bore with a mild roller cam, AFR heads and pistons that yield 14.2 for compression. It's just a street beater, although it has been 10.50's in a street 68 Camaro, and now it has more work done to it.

[BrazilianZ28Camaro]

What ignition timing the engine is set at?

What about the A/F curve and fuel system?

[nevdos]

Id say heads are probably too small for the cubes IMO
But with that said, i also think the car is too heavy for a glide and probably would 60 ft and 330 better with a 3 speed trans
Also carb may be a tad small and i think 1-34-1-7/8 header would be best
I had a 11-5 to 1 383 with out of the box AFR 227 heads with less cam,gear,converter in a 3000 pd car run 10.50s-10.60s in Denver(regular summer air at over 8000ft density altitude)
I think you need to look at everything again as something it missing for this engine to not be making more power
Good luck

[F-BIRD'88]

Is the #3350 weight car+ driver, or just the car's weight allone?

[blykins]

600 horsepower is certainly a realistic goal with that combination.

X2.

[clutchdude]

I think its doable, but tough.

I built a 383 with nearly the exact specs your 408 uses, cam is within 1 degree on intake and exhaust and similar lift.

AFR 210 heads with the AFR cnc comp porting on them.

Car ran 10.30-50 at 128mph 2800 ft with a 750 and vic jr at 2900 lbs, Very efficient car jerico clutchless 4 speed and 8.8 rear end.

I put a old school Crower stack injector on alcohol on it, second pass on it.. it went a 9.80 @ 135 so between the injector and alcohol it went alot faster. Fuel maybe, extra airlow probably. Shift at 7k go thru the lights at 7500

Last time out with that engine and first time at bakersfield, i put a vacuum pump on the engine. That was the only change from the 9.80 pass at palmdale.
1/8 time at palmdale was a 6.26, bakersfield was a 6.004. Granted Bakersfield is about 1500 hundred feet lower elevation.

It ended up going 9.50 @ 138 @ 2950 lbs

p.s. in the beginning carb and gas and turbo 400 w/brake, it went 10.80's @ 123. First pass with the jerico it went 10.25 @ 128. An efficient drivetrain makes a Huge improvement.

Also here is a video of the last bakersfield run with that combo only 1/8 pass 6.004 @ 112.5 2950 lbs

http://www.youtube.com/watch?v=top9RV_YFI0

[clutchdude]

This engine was never on a engine dyno, only on a clayton.

It made 550hp and 550 torque to the rear wheels

Oh and my carb was a stock holly 750dp with annular boosters and 1 3/4 headers and yes it had mufflers...lol

[user-9274568]

Here is the valve train on my 600hp 406 SBC.. j/k 1/2 pushrods is a little overkill IMO..

[Strange Magic]

i also think the car is too heavy for a glide

This statement is pure garbage and just another rumor passed around the internet.

[nevdos]

i also think the car is too heavy for a glide

.

Strange Magic wrote"
This statement is pure garbage and just another rumor passed around the internet

Bring your opinion to the real world where everyone doesnt race in East coast ,near-sub zero d/a and lest see how it works out for ya

[cgarb]

There is more to that statement than just too heavy for a glide or not. Still boils down to application. I had a glide in my 3300lb Buick. It functioned just fine. I replaced it with a TH350 because with the 355 I had in there it had a poor initial movement. I couldn't cut a light where I wanted to leave. It was either .080 bulb or -.020. I struggled with it for a year or two then swapped it out. My own personal choice. When I put in the TH350 the 60ft picked up about .08 to .01 and my lights came around. That was the only et gain I saw, MPH was a little slower and gained in 60ft.

[Charvelrhoads]

Is the #3350 weight car+ driver, or just the car's weight alone?

3350 lbs. car, driver, and full of fuel, ready to go.

[quote="BrazilianZ28Camaro"
What ignition timing the engine is set at?
What about the A/F curve and fuel system?[/quote]
Timing is 36degrees, seems to like it best there. Tried 32 to 38.
Fuel curve? Not sure. Stock 92 jets in 950HP way to lean, ended up at 98, seemed to like this best. 3.5 power valves.
Did a wide open throttle shutdown to check plugs and fuel in carb. Both bowls were full.

What RPM are you shifting at?
What RPM are you going thru the lights at?

Tried shifting from 6900 to 7600. Seems to like 7400 and that's where it is now.
Goes thru the lights at about 7000.

Consensus seems to be a problem with the AFR cylinder heads. I have a set of Brodix Track 1 221 intake, 2.055 in. 1.60 ex heads.
How would they perform with this application?

Thank you everyone for your input and sharing your experiences. I've got a lot to learn!!

[Strange Magic]

Bring your opinion to the real world where everyone doesnt race in East coast ,near-sub zero d/a and lest see how it works out for ya

Funny that you mention that. We where the only normally aspirated application that qualified in the quick 16 (madcapp/Finelines) at Bandimere, when all others had nitrous and blowers all over there junk. Qualified in the middle of the field at 9800da and a 7.48 et. The same deal at vegas went 7.0.


P.S. That's right...............with a POWERGLIDE and a conventional valve angle (26 degree) BBC Chevrolet head, normally aspirated.

P.S. You can ask Steve at Finelines, Mario, or Joe who used to be at Madcapp about my junk.

The engine to the right (black one) is being shipped to V's sons place (Lucas) and it will be installed into a ride whereas the owner is from Fort Collins.

Please spare me your bullshyt!



Here is the junker below that ran 7.48 @ 9800feet of da in Denver

[vortecpro]

Just for the record Strange, state the baro up there, no one wants to believe me.