How much horsepower & torque

JPCobra · #1 (**permalink**) 05-02-2003, 12:30 PM

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?

SSSnake · #2 (**permalink**) 05-02-2003, 12:44 PM

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

JPCobra · #3 (**permalink**) 05-02-2003, 12:50 PM

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

750hp · #4 (**permalink**) 05-03-2003, 07:42 AM

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....

JPCobra · #5 (**permalink**) 05-03-2003, 11:34 AM

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?

750hp · #6 (**permalink**) 05-04-2003, 05:35 AM

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.

JPCobra · #7 (**permalink**) 05-04-2003, 05:00 PM

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?

agro1 · #8 (**permalink**) 05-05-2003, 12:27 PM

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...

750hp · #9 (**permalink**) 05-05-2003, 03:52 PM

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.

Mr.Fixit · #10 (**permalink**) 05-09-2003, 09:25 AM

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.