HP VS Torque

[fe66comet]

I was sure if I was going to step i do do on this one but here it goes. If I have a projected level of 675- 700 HP with fuel injection. Where would my torque level be with a 4.25 stroke 4.080 bore (445). My plan is 1175 cfm on the throttle body with a trick flow Cleveland Box R intake, runners flow 300 cfm.  Headers are 1.75 primary with 3" collectors, full length exhaust behind the rear tire. Camshaft has 594/598 lift,287/293 duration @112*. Cylinder heads are Edelbrock performer with a full race prep from Barry with stage x valves and 11/32 guides. Topping it of is a set of T&D race rockers with Beehive springs. Compression is 10:1 with a 1500-6500 rpm range. Any suggestions as to torque this engine might produce? Thanks Jon

[Joe-JDC]

Multiply cubic inches by 1.2, and you should be close(534).  However, camshaft and compression will affect that considerably.     Joe-JDC

[blykins]

I'm more curious as to how you're going to get 700 hp out of a 445 with only 10:1 compression, .600" lift, and only going to 6500.   Forced induction?  Spray?

The answer to that will also dictate the answer to your torque question. 

 

[LuxurySportCoupe]

X2 on what Brent says. I'm building a similar 445, with a slightly bigger solid roller, planning to spin it to almost 7k, and I doubt it will get to 600 hp.

[BH107]

His build has been discussed before.

http://fepower.net/simplemachinesforum/index.php?topic=1719.0

Should be interesting to see how it turns out.

[Lenz]

Came upon this info in Hot Rod credited to Westech Performance group:  Multiply cubic inches by 1.25, =556.25, this would be estimated peak torque.  Roughly 10% of this will be used up in the generation of horsepower, so multiply that figure by .9, =500.6 net torque.  Multiply this number by how fast you're gonna spin the engine.  I would imagine that with a range starting at 1,500 rpm you realistically would be looking at roughly 6,000 rpm if the setup is truly working hard at 1,500, so at that point you plug in the equation:  HP = TQ x RPM /5,252.  Therefore one could roughly assume that at 10:1 compression with all the right breathing, fuel and required goodies the thing should generate about 572 HP.

Now take that +/- a whole #%&@load of variables and you'll have the number you're looking for .

[Drew Pojedinec]

Yes but Lenz you are forgetting something
*waves the magic fuel injection wand*



hehehe

[fe66comet]

Never mind see ya at the track lol. I get 500 hp out of a vortech 383 chevy with iron heads. If I get that out of a 20,000 dollar engine it becomes a mailbox.

[BH107]

Don't let everyone discourage you. I for one would love to here more about this build as it progresses. I hope to be pleasantly supprised by your numbers when you get it all done.

[fe66comet]

I think it will work out as most builders are getting 1.5 hp per cube in a normally aspirated engine. It just takes a lot of attention to details. The camshaft is my only concern. Internally very little resembles a FE as everything has been modeled to modern standards with a roller cam, T&D race rockers, heart shaped chambers, 350 cfm intakes. 2.20\ 1.6 valves with swirl polished tulip head and undercut stems. The intake will be fully ported and polished to flow 350 cfm into one of Jays intake adapters. I am using an electric CVR water pump with Jays manifolds and electric fans. I am also adapting 351 Windsor accessory drive brackets for serpentine drive to save 15% frictional loss vs. V belt. Also a late model alternator for higher output with less frictional drag. Fuel injection will be handled by a 1993 Mustang reprogrammed ecm to handle emissions  duties also. The injection system can easily handle 700 normally aspirated HP on a 427 cubic inch SVO Cleveland block with 220 cc heads. As I said I am in the 350 cfm range and have larger valves along with a bigger displacement so that should get my peak HP from 7500 rpm on the 351 to 6200 on the FE.

[lovehamr]

Jon, I'm following your build with interest but I still haven't read how you're going to spin a hydro/roller to 7k?  I'm running a rather stout one myself and there's no way I could get 7k rpm out of it.

[blykins]

Torque will be somewhere around 1.2-1.25 lb-ft per cubic inch.  I wouldn't expect much more than that unless you were blowing or spraying. 

So what do the heads flow at .600" lift? 

If I were to make a guess as to how much hp you'll make, I would guess around 575-580.   I'm sure you have nice heads, but you don't have enough cam to take advantage of them.  Compression is too low, cam duration is too small. 

[ScotiaFE]

$20,000 seriously?
You can do a pretty stout 482 in the shed for a hell of a lot less.
I know I can.

[fe66comet]

Most my money is in the heads, cam,induction, electronics, mass air flow conversion port work and other stuff to make things work. The bottom end is about 4000 of my cost. That does not include the fuel system or cooling either. The intake alone is 700 plus the port work is 400, Jay's adapter 400, throttle body 500 with plate. Then the power train module 600, mass air flow conversion 1200, sensor kit 300, harness 600 and all the labor to dyno tune, gaskets and all that. That is just the induction that attaches to the engine. There is still all the ignition that I have to go with it, that is another 1500. It all adds up quick as we all know.

[sumfoo1]

not to be a jerk but i'm expecting my engine to be in the 650 range

This is on ported pond heads, edelbrock victor EFI, with .675 lift long duration (i think it was 262@.05) solid roller cam and on a 511 cid motor.

I will be impressed to see what you come up with.

Course... my engine is still yet to be seen... gonna have to make a phone call on that today.