Master spreadsheet for calcuating engine performance?

[kenikh]

I have spent the last 2 hours rummaging through past posts by John, et al, trying to figure out the mathematics of calculating BALLPARK engine performance numbers from spec. It seems that torque/HP curves could be calculated by entering:

cam spec (lift, duration, overlap, etc. at 1mm)
bore
stroke
port size
valve size
static CR

It's just math (albeit somewhat complex math), right? Does anyone have a spreadsheet that I can punch these specs into and get a nice little virtual dyno graph? My end goal is to figure out what optimal port diameter is for a given cam and displacement.

Tell me if I am off base here.

[Steve@Rennsport]

There used to be a program called Desktop Dyno that was amazingly accurate IF you knew how to input all the necessary information properly.

Dunno if its still available but worth a look.

[kenikh]

Thanks, Steve.

Their product, DynoSim, does what I want:

http://www.proracingsim.com/purchasejac2.htm

Not cheap at $100, but worth considering at that price. Their Dynomation product is a gearheads wet dream, but over the top for most hobbyists and kind of expensive for just being a toy.

Does anybody have anything free before I drop the coin?

[Aurel]

Maybe play with this...

http://www.virtualengine2000.com/Calculator.htm

Aurel

[Steve@Rennsport]

Originally Posted by kenikh

Thanks, Steve.

Their product, DynoSim, does what I want:

http://www.proracingsim.com/purchasejac2.htm

Not cheap at $100, but worth considering at that price. Their Dynomation product is a gearheads wet dream, but over the top for most hobbyists and kind of expensive for just being a toy.

Does anybody have anything free before I drop the coin?

You are quite welcome,..

I have both Desktop Dyno and Dynomation and both are excellent pieces of work for the price, respectively. It looks like DynoSim is a hybrid of the two and for the $$$, thats a bargain (IMHO, of course).

Like all engine simulation, these are only as accurate as the data that get entered but they can produce useful information for the purposes of comparison.

[kenikh]

Originally Posted by Aurel

Maybe play with this...

http://www.virtualengine2000.com/Calculator.htm

Aurel

Tried it. Too simplistic.

[jcge]

Bosch Motorsport created Lapsim Toolbox to calc not only engine output, but vehicle dynamics simulation as well.....definitely not for the faint of heart

http://www.bosch-motorsport.com/content/downloads/Software/lapsimengine.pdf

[cnavarro]

Dynomation is a great piece of software. Equally good, but not as expensive (anymore that is), is Engine Analyzer Pro. I've used it for years and it's usually within 5% of actual output, if you enter EVERYTHING in properly. (it's usually low, which is a good thing). The best part of using such a program is to see differential effects of CR or cam changes. The actual number doesn't matter as much as the change it is reporting between different configurations.

[racing97]

Try Pipe Max by Larry Meaux it is about $50.00 and will give you everything you need to know to bring your project up to speed. It will give you specific design targets as well as the HP numbers.

regards

[turboteener]

Pipe Max is a good program. Many top head porters are using it.

[JohnJL]

Hahaha...virtualengine2000 has a "Loan Repayments" calculator embedded in it!