Club Cobra - How much horsepower & torque

Club Cobra (http://www.clubcobra.com/forums/)

- Shop Talk (http://www.clubcobra.com/forums/shop-talk/)

- - How much horsepower & torque (http://www.clubcobra.com/forums/shop-talk/41139-how-much-horsepower-torque.html)

How much horsepower & torque

Has any one built a 429 or 460 using details out of the Ford Performance book by Pat Ganahl? I had a set of '69 heads machiened with 2.245 in. and 1.725 ex. valves hardened ex. seats, 3 angle valve job 30 over 11.0 to 1 trw piststons, custom comp cam .585 in. .610 ex. lift with 253 in. 260 ex. @.050 duration 108 degree lobe centers, Performer RPM intake 850 CFM Holly carb. What would be a good estamate on Horsepower and Torque for this combo?

I ran those specs through Desktop Dyno at 460 cubic inches and came out with 475hp at 6500 rpm and 466ft/lbs of torque at 5000rpm. This should be somewhere in the ballpark.

Glenn

Thanks Glenn, I was hoppeing for between 500 and 600.

JP - I have an almost identical motor to that in my other car. Only difference was that I have 10.25:1 comp. It made 530hp at the flywheel.

Do you really want 11:1? It seems like it's too much compression for pump gas, but not high enough to make the extra power to justify Avgas....

That was the c/r for the original factory pistons accoriding to Pats book. I could install a thicker head gasket to lower this number. Was there any other differences in your build up?

You're testing my memory now, but I'm pretty sure that my specs are the following:
D0Ve heads ('70)
Same valve sizes
Another .010" on the exhaust lift
JE inverted dome pistons
Edelbrock Victor manifold
850DP Holley
MSD dist and 7AL
Roller rockers

I also bought some Eagle rods when I bought the JE pistons. They don't make you any more power, but they're nice for peace of mind.

My manifold is to suit a Dominator 4500 series carb, and I used an adaptor turned upside down to fit my 850. The motor used to have 13:1 pistons in it and I had an 1150 Dominator on it then. I'd say that I lost 60 or 70hp when I dropped the compression. The difference in throttle response was unbelievable. Don't get me wrong, the motor is still a lot of fun, and the pump gas side of things is nice, but the added compression was great.

I used to run the L2443-F (from memory) TRW dome top pistons in the high-comp motor, with my small chamber heads. These same pistons were supposed to give around 11:1 comp on larger chamber heads. If you have these pistons, you can safely mill some material off the piston crown to drop you compression to pump-gas levels.

I beleve the piston's are L2366-F's from TRW. Do you think that this cam is to big for this motor and might be keeping h/p down? How well did your motor hold up and is it streetable?

Nothing can compare to high compression - I'm running 12:5.1 and you hear it immediatly- and smell it too ;) Love that race fuel...

That cam is fine for your combo. In a 302, it might sound a bit radical, but with 460 cubes, it'll give you a nice lopey idle with total streetability.

My motor's going fine - I could never be accused of babying it, and I haven't even had to reset the rockers in the last 3 years.... With the good rods and pistons inside, and the mild ported heads, it makes power to 7000rpm, but in the interests of keeping it all together I don't go over 6500. Believe me, that will be all the noise you need to make in a Cobra. :3DSMILE:

If you aren't going to spin the motor to the RPM where the cam is designed to make power, why not run a less duration cam? You'll get more torque and often more HP with a smaller cam, especially if you don't turn 7000+ rpm. Big duration cams NEED higher compression to work right.