power calculations

[roverman]

Jim or clan.I don't have chart for comparative coefficient of friction for various materials/coatings. I have been quoted .05 for a proprietory, hard anodize process. Anybody? Thanks, roverman.

[bashby]

To estimate the size of carb needed I am pretty certain that the calculation is:
 Street Carb CFM = Max RPM multiplied by Displacement (in cubic inches) then divide this by 3456, then multiply by 0.85 (volumetic efficiency). for Race multiply by 1.1 instead of 0.85.

Air Capacity (in cubic inches per minute) = RPM x Displacement (in cubic inches) divided by 2.
Air capacity (in cubic feet per minute) = RPM x Displacement (in cubic inches) divided by 3456.
Cylinder volume = pi/4 x bore squared (in inches) x stroke (in inches).
Stroke = displacement (in cubic inches) divided by : pi/4 x bore squared (in inches) x number of cylinders.
Bore = the square root of: Displacement (in cubic inches) divided by: p/4 x stroke (in inches) x number of cylinders.

This is old school (and I am sort of old) but it should be pretty close.
There is an "Auto Math" book that was published back in the early 90's that showcase these calculations

[MGBV8]

Lots of easy to use automotive calculators:

http://www.avenger-valkyrie.org/techinfo/calculators.htm

[BlownMGB-V8]

Thanks Carl, Those will probably be real helpful. The hard part is putting together the right formula so that the results make sense. Luckily there are smarter people than me who are willing to help with it, and at this point it looks like the math is worked out. Now it's down to material compatibilities. Never easy.

Jim

[roverman]

Jim, I'm wondering, will the frictional coefficients be a factor in the calc's ?

[BlownMGB-V8]

I doubt it Art, we've left some leeway in the figures and in the end the unit will be instrumented to see how it performs. Coolant flow can be adjusted up or down to optimize cooling on that side so the limiting factor appears to be evaporator size and air flow restriction and we've gone as big as we can go there. Right now we're looking at n-hexane as a coolant and need to pump about 6 gpm (360 gph) through the core. I'll be running a test in the next day or two to see if that is practical or not.

Jim