[sb454chevy]

i have a chevy 400 .030 over with flattop pistons with 882 chevy heads that were bowl blended and gasket matched with 76cc chambers. the cam is .488 intake .510 ex 234 in and 244 ex at .050 duration with a performer rpm intake can anyone tell me what the compression is and take a guess on the horsepower? the piston have 7cc valve cuts and the gasket is .038x4.200. thank you for any help -charlie

[Regal Beagle]

Originally Posted by sb454chevy

i have a chevy 400 .030 over with flattop pistons with 882 chevy heads that were bowl blended and gasket matched with 76cc chambers. the cam is .488 intake .510 ex 234 in and 244 ex at .050 duration with a performer rpm intake can anyone tell me what the compression is and take a guess on the horsepower? the piston have 7cc valve cuts and the gasket is .038x4.200. thank you for any help -charlie

Need to know how far in the hole you pistons are to figure out your CR.
Once you know that you can go to this link to plug in the numbers and get your CR.

http://www.csgnetwork.com/compcalc.html


Beagle

[sb454chevy]

the block was decked and the pistons are .005 in. thank you

[Regal Beagle]

I come up with 10.0:1 CR.
Need more details such as weight of your car to take a guess at the Horsepower.
There are various online dyno programs that can give you a good guess at horsepower.
Try this one. http://www.speedwaybids.com/tech/ezonlinedyno.html

[techinspector1]

Hey Charlie, what carb? Headers? What size? Through the mufflers or not? Manufacturer and # of the cam? Valve sizes?

[sb454chevy]

im sorry. its a holley 750 dp, the headers are 1-3/4 though 2 chamber flowmaster mufflers, the cam is a edelbrook performer rpm hyd cam #7102, and the car weighs 3550 with me in it. thank you for any help -charlie

[jake_arcticcat]

Hi, according to desktop dyno 2003, with open exhaust your at,

393 foot pounds 4500rpm
394 horse power 6000rpm

With mufflers that drops to

376 foot pounds and 364 horse power

[454C10]

Sounds like you have a nice engine, except for the heads.

Your setup with a good set of aftermarket aluminum heads would make another 70 or 80 hp. Look for 190 to 210cc intake ports and 70 to 76 cc chambers to keep cr between 10 and 10.6 cr.

even a set of performer rpm heads (170cc, 70cc chambers in think) would make a big difference in power over the 882's. 50+hp.

[Sixtyninemercury]

Originally Posted by Regal Beagle

I come up with 10.0:1 CR.
Need more details such as weight of your car to take a guess at the Horsepower.
There are various online dyno programs that can give you a good guess at horsepower.
Try this one. http://www.speedwaybids.com/tech/ezonlinedyno.html

Why would you need to know how much his ride weighs to guesstimate HP?

[ImRoyaltyInMyChevy]

ok I put in all your specs on Desktop Dino 2000, I didn't know what kind of intake so I did both. ET's done with a weight of 3550

dual-plan, large tube headers with exhaust
465 HP at 6000-6500 451 TQ at 4500 ET 12.06 @ 111.7

single-plan, large tube headers with exhaust
508 HP at 6000-6500 471 TQ at 5000 ET 11.71 @ 115


dual-plan, large tube headers open
515 HP at 6500-7000 466 TQ at 5000 ET 11.65 @ 115.5

single plan, large tube headers open
556 HP at 6500-7000 483 TQ at 5000 ET 11.36 @ 118.5

[UR50SLO]

Had a real similar setup in my 89 Camaro with 3:89 Gear back 15yrs ago.

With the iron heads you'll be mid to high 12's depending on your rear gear and stall converter.

That RPM camshaft won't come alive till at least 3500rpm then it really pulls good. Lumpy idle ect. Tuned with one before.. not my cam choice for sure.

If you went with a RPM as suggested above with 70cc chamber it'll help a TON! I know edelbrock has approx power with that cam/mnfld and heads. Look in their catalog.

With the right stall and gear and tune it'll go 11's.

Mine was 11.6 to 11.7's on the motor and mid 10's on 150hp.

Now I'm down 2cyl and run 10.3's @ 133mph on 93oct on Drag radials and get 20mpg!!!
Nothing like a Buick Turbo V6!
Good luck with the build,
Scott~