A complete rip off of my original super dooper Excel engine calculator, but it's a worthy successor (and the only one since I lost mine in a drive crash! :)
Cheers, - Tom Craig Overend wrote: > David, > increasing the piston pin height (the distance from the piston > pin centre to the top of the piston) will bring the piston closer to > the cylinder head and therefore increase the compression ratio by > reducing the area available for combustion. > > What you may be encountering is the way in which the program > interprets "below deck". If a piston is below the block deck a > negative measurement may need be input. for example a standard L18 > piston sits 0.5mm below deck so you may need to enter -0.5. > > If you didn't get my last post get > http://www.ozdat.com/members/uploads/datsun_engine_calculator_v1.0.xls > it includes block deck height, piston pin height with automatic > calculation of piston to deck clearance or the option to manually set > the piston to deck clearance if you don't know the block deck height > rod length or stroke. > > Hope that helps, > Craig. > > David Costello wrote: > >> Guys I'm having trouble getting my brain around something to do with >> calculating compression ratio's. I know the formula I'm using is >> correct, I've tried using figures for motors I allready know the >> compression ratio of and it's been spot on every time. the thing >> that's got me stumped is if you increase the piston height value, the >> final compression ratio decreases. I'm having trouble understanding >> how that works, shouldn't it increase compression since it's bringing >> the piston closer to deck? I've tried using 2 compression ratio >> calculators as well, and exactly the same thing happens. The >> compression ratio calculator doesn't have a "piston height" option, >> but it does have "piston below deck" field, and if you bring the >> piston closer to the deck then exactly the same thing >> happens....compression ratio DECREASES this has got me stumped >> :(maybe I should stop trying using mathematical formulae at ungodly >> hours of the morning :) hehe Dave >> >> >> --membersozdat------------------------------------------------------- >> OZDAT Mailing List Please Note:- >> Send (un)subscribe requests to [EMAIL PROTECTED] >> Send submissions to [EMAIL PROTECTED] >> No unauthorised redistribution of this email >> http://www.ozdat.com/ozdatonline/index.htm >> http://www.ozdat.com/ozdatonline/listindex.html >> http://www.mail-archive.com/[email protected]/ >> --------------------------------------------------------------------- >> > > --membersozdat------------------------------------------------------- > OZDAT Mailing List Please Note:- > Send (un)subscribe requests to [EMAIL PROTECTED] > Send submissions to [EMAIL PROTECTED] > No unauthorised redistribution of this email > http://www.ozdat.com/ozdatonline/index.htm > http://www.ozdat.com/ozdatonline/listindex.html > http://www.mail-archive.com/[email protected]/ > --------------------------------------------------------------------- --membersozdat------------------------------------------------------- OZDAT Mailing List Please Note:- Send (un)subscribe requests to [EMAIL PROTECTED] Send submissions to [EMAIL PROTECTED] No unauthorised redistribution of this email http://www.ozdat.com/ozdatonline/index.htm http://www.ozdat.com/ozdatonline/listindex.html http://www.mail-archive.com/[email protected]/ ---------------------------------------------------------------------
