Just curious if some of you could help me do a little math.
If I took a stock 302 crank, rods at 5.310" long, and pistons for a 331 stroker engine, what would I end up with in cubic inches at .030 over bore?
Also, would my compression ratio be different with stock 64cc(I think?) heads? how about if I shaved .010 off them?
Sorry to be difficult with the questions here.
"Christopher Wall" wrote
You gotta tell us the pin height for the piston. Is it a stock 302 piston, does it have a raised wrist pin? Which brand of piston? Still missing some info.
Stroke and bore are the only two variables that matter here for displacement. Go here for some good calculaters
As for compression ratio, you need to know things like piston pin height, deck height, gasket thickness, piston dish, etc. Calculating compression ratio is a little difficult. Unless you assemble it and measure everything, you'll only come close, not exact. You'll probably be off by .2-.4.
Kinda makes those classes you skipped look a little more realistic????? Bore/stroke... google up volume of a cylinder...... pay attention to the formula and you will never be someones slave again. Add CC volume plus squish times 8 = displacement. I really don't understand your piston/rod choice...... you may run into some spendy problems if the numbers don't compute. Bottom line is that you will have a 302 bored .030" and questionable geometry.
If it makes you feel any better, I only went to grade 8........but I was lucky enough to realize that math and geometry play a big role in our daily lives. Learn this stuff... it will serve you well.
In part: ">If it makes you feel any better, I only went to grade 8........but I was
These are very important words! Everything on a car, from the French Curve used by the stylist to the slide rule (for the early engineering) is math related...as is much of life in general.
bradtx
Well, to be honest, I don't know the piston pin height. As I mentioned, they're pistons for a 331 stroker (Hawk racing I think), the ones that don't intersect the oil ringlands. Flat top, or a 10cc dish. The rods I found (5.315") are shorter than the usual 5.4 inch stroker rods I see for the 331 and 347 kits. (stock is 5.090" form what I've read?) How about just using a 331/347 stroker crank with stock rods and pistons? ( I know, Why not just buy a whole stroker kit and KNOW what I'm getting, right?) I'm just curious what kind of workable combinations I can come up with, if they'll even work.
I'm not hugely concerned with CR as long as it's under 10:1 as it is a street build-up. But the heads are going to be worked (ported, bigger valves) and shaved a little.
Any books out there with a whole bunch of different engine math stuff so I don't have to keep bothering you all with these rediculous questions?!?!
--Chris
Yeah, I just wish they had offered a mechanics class in highschool! Would have defenately had me more interested in learning math and such. I'm getting to know all this stuff on my own now, and with the help of people like you! (Geeze, did that really sound like a PBS advertisement?) I slacked in highschool, and now in college I'm having to try to keep up. I'll get there though.
--Chris
Or, you could make use of these. I found them somewhere on the internet at some point long ago....
Ok... That seems to have failed Horribly.. send me an E-mail to denlspe (at) gmail.removethispart.com
Erimikos
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