Calculating Horsepower

Venom S · #1 (**permalink**) 01-09-2002, 11:15 AM

Can engine horsepower be estimated using all the engine specs (bore, stroke, compression, cam lift)?

Venom_S

CobraEd · #2 (**permalink**) 01-09-2002, 11:20 AM

Yes, there are computer programs now for PCs that have all the product info for most stuff with formulas for the gain they provide. You plug in all your specs and info and the program gives you your hp and torque. These have proven to be consistantly within 5%. HoundDog has one of these programs, maybe you can give him your info, and he can run it for you.

Ed

Hotfingrs · #3 (**permalink**) 01-09-2002, 11:27 AM

I have DesktopDyno and EngineJr and they both do a pretty good job. The EngineJr program is a little more detailed. But the DesktopDyno is probably easier for you to find. Summit, Jegs etc have it.....

Venom S · #4 (**permalink**) 01-09-2002, 11:36 AM

Thanks

hound dog · #5 (**permalink**) 01-09-2002, 11:47 AM

Venom S,
I've been using Dyno 2000 and from all I've heard it is supposed to be an excellent and accurate program. You can run horsepower, torque, engine vacuum, efficiency, etc. for just about any engine you desire, even 4 cylinder rice burners and bowties. Don't have the URL, but just run a search for Dyno 2000 and you should find where to buy it. If you're going to build an engine it is well worth the $40.00 or so you'll spent on the software. How much would you spend just on a cam swap?
h dog

CCX33911 · #6 (**permalink**) 01-09-2002, 11:53 AM

They also have Drag 2000 and a added disk with ~3500 cam shafts. The company is motion software and they have a web site. They bundle all three disks for a discount. The dyno data will transition into the Drag simulation. The Drag software is nice but does not account for driver feathering the throttle or allowing clutch slip in first gear to keep from smoking the tires, etc. Otherwise seems nice. You definately get trends, etc.

Venom S · #7 (**permalink**) 01-09-2002, 12:24 PM

I just ran enginepro demo using all the engine specs. It calculates I will have 741 horsepower and 644 pounds of torque at the flywheel through headers with mufflers.

Not a bad little snake

Venom_S

Dave Samson · #8 (**permalink**) 01-09-2002, 02:30 PM

Venom_S,
How do you expect to put all that torque through a TKO ?

Venom S · #9 (**permalink**) 01-09-2002, 02:31 PM

Dave -

Very gently

Venom_S

Dave Samson · #10 (**permalink**) 01-09-2002, 02:39 PM

Suggest you use 1" wide bicycle tires at the back and just enjoy the wheel spin.

Hotfingrs · #11 (**permalink**) 01-09-2002, 03:05 PM

Venon S

Go to Radio Shack and get a torque splitter....Then you won't have any problems

Venom S · #12 (**permalink**) 01-09-2002, 03:13 PM

I think the solution is to remove 4 spark plugs and make it a 370 HP 4-cylinder

Venom_S

Dave Samson · #13 (**permalink**) 01-09-2002, 03:16 PM

take out the crown gear from the diff.

cobish · #14 (**permalink**) 01-19-2002, 08:09 AM

venom s,
there is a book on the market "HPBooks" AutoMath Handbook by John Lawlor ISBN 1-55788-0204-4 about $17.00 US.
it is all in there.

crillyiv · #15 (**permalink**) 01-19-2002, 11:38 AM

I am just wondering how many people have broken TKOs, or similar, transmissions driving on the street or on a road course. It seems to me, in my ignorance perhaps, that you are not going to break the trans because you couldn't hook up that much torque and hp on the street if you tried. Unless of course you were running big drag slicks. I also think that without the shock loads of starting from a dead stop the trans should live. Banging gears at speed would produce some pretty high shock loads too so maybe that should be avoided as well. I dunno.

Bottom line: I know the TKO II is rated for something like 490 ft lbs of torque. Heck I am getting almost 700 ft lbs from my engine and running it through a regular TKO. I believe that not drag racing and not banging the gears really hard while on a road course should allow my trans to live. Then again if you can afford a better/stronger trans, go for it.

I can't wait to see the engine with those Webers and see how it all works out. Yes, I sometimes dream of running Webers.

Added by Jim: 591 ft lbs at the rear wheels at 3500 rpm, assuming 17% loss through drivetrain yields 692 ft lbs at the flywheel at 3500.

Dave Samson · #16 (**permalink**) 01-19-2002, 02:26 PM

Jim,
Just a small correction for you. If you take the calculated 692 lbs/ft. and subtract 17%, you find that you do not get the dynoed 591 lbs/ft. What you need to do is take the 591 / 83 * 100 = 712.
Now you're smiling eh ?

crillyiv · #17 (**permalink**) 01-19-2002, 03:34 PM

Dave,
Yeah, I'm smiling. Laughing at myself too. Sucks to be human sometimes

You were correct of course. That also raised the hp to 607 at 5500 rpm. That was the highest rpm the engine was run on the chassis dyno. We were just trying to get an idea of where the engine is now.

Thanks for the correction.

Venom S · #18 (**permalink**) 01-20-2002, 09:18 AM

Jim -

Where did you ever find an aluminum 460 block?

Venom_S

crillyiv · #19 (**permalink**) 01-20-2002, 09:55 AM

The Al block was in the car when I bought it used. The original owner, David Sugg, started with a SB stroker. He bought the car from the Olthoffs in NC. They got the Al block, from Ford I believe, and offered it to David. They then built and installed it in #239.

They are hard to find and very expensive. I never would have been able to get one had it not been in the car. I have the info on where you can get one if you want it. They are not that much lighter than the regular cast 460 blocks. They are built for strength and being bored/stroked to ridiculous dimensions.

Venom S · #20 (**permalink**) 01-20-2002, 10:01 AM

Seeing that my engine cost has already surpassed $11K, I think I will just go with the iron block. Thanks anyway.

Venom_S

PS - you have mail