can anyone tell me how to calculate horsepower using the block,head specs,cam specs,piston type and intake?
im just a guy thats been lurking around here in the shadows for a while trying to soak up the knowledge ive found here and enjoying the treads.
I suggest you consult "Internal Combustion Engine Fundamentals" by Dr. John Heywood (MIT...And that's not Mississippi Institute of Taxidermy.) It'll help you determine IMEP and BMEP. With thoses values, engine displacement, speed (RPM) and a few other things you can arrive at brake horsepower plus or minus a tad. Regards.
download this old DOS shareware program called Drag Strip Plus, and have fun! don't expect too much accuracy though...
i dont think you can calculate hp with the varibles you mention. if you know the wieght and a 1/4 mile time etc and speed there are formulas for the hp neccesary. i know some guys who add up all the hp you are supposed to get with each mod and think thats what you end up with.....
First find a Proney Brake Machine. Formula is; PLANK ------- 33,000 　 P - indicated mean effective pressure L - length of stroke A - area of piston head in square inches N - number of power strokes per minute K - number of cylinders
I just use the fact that all internal combustion engines are capable of producing a given amount of HP and/or TQ per cubic inch. This is based on engine design(stroke/bore/rod length/reciprocating weight/valve size/runner efficiency/total intake runner-vs-plenum volume/etc.) and are as follows: SBC: 2hp/ci BBC: 2-3hp/ci Early Hemi:1.25hp/ci Late Hemi: 1.75hp/ci SB mopar:1hp/ci BB mopar:1.125hp/ci SBF: .5625hp/ci BBF: .75hp/ci I do have the formulas for other engines as well, just email me at boydoiknowhorsepowerandasyoucanseeilikesbcnbbcmuchmorethananythingelse@imayahoo.com and tell me what engine you have and I will give you the correct formula.
you scared him off..... I still don't see an intro or I might share a tip about the free software from a major cam manufacturer that is probably the best bet in a shadowy world of optimistic bullshit and blind hope....
COME ON SCOTTY...Ok, fine I'll intro him. He is xronmowerx, he is a fng from Ohio. I think he is into mowers. He has a question about hp calculating and after lurking around here for some time he finally decided to join and ask for our/your help....now what is this free stuff you seem to want to keep secret?
could be the Comp Cams "Cam Quest" software that you can download at their web page http://www.compcams.com/camquest/default.asp
Hahahaha.... reminds me of the old flathead hop up books from the 50s and 60s. Carbs... 10-15hp Port and relieve... 10hp Cam... 10-15hp.... Heads.... 10hp Bore and stroke .... 10-20 hp etc, etc...... so simplistic, so easy, so a load of bollocks....
Take the intake port flow in cfm and multiply by 2 to get a rough idea of most engines HP 'potential'.
RON...there is definantly a way, but i don't know anyone on the planet who can do it accuratly. and neither do they...POP.
This is not exact of coarse, but it will get you in the ball park. http://www.speedwaybids.com/tech/ezonlinedyno.html Kevin Ooltewah Speed Shop
I always use head cfm x2 and multiply by a guess of volumetric efficiency (75% for stock heads, 85% for good aftermarket street, 100% for the hairy ones) and that should get you close, assuming nothing blatantly doesn't match. Another good one is to take what you think it makes and subtract 100hp, that's usually close......
SBC: 2hp/ci BBC: 2-3hp/ci Early Hemi:1.25hp/ci Late Hemi: 1.75hp/ci SB mopar:1hp/ci BB mopar:1.125hp/ci SBF: .5625hp/ci BBF: .75hp/ci You should really point out that "this is a political and sarcastic comment", lest you frighten some of the children.
Panic, look closely at the email address I put in that same post....read it slowly, seperating it into words....that should explain it all!!!
That's like trying to calculate how good someone is in bed based on their stats and measurements. Is it me or can you come up with a sex analogy for almost anything engine-related?
I use a program all the time in my engine business. We can alway come with in 2 /10 of a second in modeling a car and chassis set up and engine. Occasionally we have been right on the money. The modeling programs for engines are very accurate IF YOU DONT LIE to them. I will do you one of you like. Send me your specs by PM. By the way half evil, The day a sbc makes more hp per cubic inch than a hemi will be a frosty friday in that evil place. Probably you are one of those dudes who tells people the small block chevy was the first North American engine to be produced with more than 1 hp or more per cubic inch. WRONG!!!!!!!!!!! 55 Chrysler 300 A early hemi was. It takes a huge cubic inched BBChev to produce 800 plus hp. A superstock 426cu in say 69 cuda SS/A have been approaching that for several years. You chevy guys always have your bowties tied a little tight I think. Don If one just wants a quick idea you can use cam lift /500 X cu inches . It isnt super accurate but is a good ball park for street hp. (for cam lift use for instance 550 not .550) PLANK is theoretical hp and is not relavent to anything other than licensing by hp rating perhaps. HP = rpm X torque in ft .lbs divided by 5252 Torque and HP should always be the same at 5252 RPM
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