Patrick Golder states in a previous posting that boring out an engine will
not increase compression ratio.
Well, seeing as I have nothing to do but sit behind a PC, I ran the
math.
The compression ratio was increased in my model (Triumph 2000cc 6-cyl) by
.10, after a boring out of .030 inches. The cylinder head volume was left
constant.
Interestingly enough, if I bored out the cylinder head combustion chamber
along with the cylinder itself, the compression ratio remained the same.
As a note, work output of a piston cylinder is given by the theoretical
equation P*V, where P is pressure, and V is Total Volume. (heat and frictional
losses neglected). Increase either or both, and work output (Torque) will
be increased. From this it is evident that head milling is a compromising
modification, while cylinder boring is not. Practically though, the compromise
works, and head milling has been quite effective on motors that I have built.
Of course, so has boring.
I hope mentioning the word 'Torque' will not bring up more discussion
about Torque wrenches and extensions, for the sake of the non engineering-nerds
on the list. :-) However, mathematical discussions always have an answer,
and it's kind of fun to do the calcuating. Newtonian ones anyway; I'm not
talking particle mechanics here.
Greg Meboe MEBOE@wsuvm1.csc.wsu.edu
Dept of Mechanical and Materials Engineering
Washington State University Pullman, Wash.
'67 Spit-6 (Daily) '74 TR-6 (In Progress)
|