Gentlemen,
Over the course of many years on this and other modeling forums the discussion of carburetion, ignition and compression ratios has come up in regard to miniature engines. We have some very skilled and educated members who are very forthcoming with very valid information in regard to ignitions but not much on the other two.
The purpose of this thread is to relate information in regard to compression ratios versus compression pressures. I know I have added my uneducated but practical knowledge more than once so for the sake of clarity I just did a search on the internet of this subject.
My short answers over the years were that compression pressures are altered by so many factors that taking a compression reading doesn't give a true picture of the static compression ratio numbers.
In my search I found these 3 articles which shed some very informative light on this subject.
http://kb-silvolite.com/article.php?action=read&A_id=36http://www.type2.com/library/engineg/comrat.htmhttp://www.ntractorclub.com/howtos/pdfs/Compression-Testing-Tutorial.pdfLong story short, build your engine as well as you can, fits and finishes, and don't get too wrapped up in compression ratios or pressures. In my opinion they are the the least critical of the 3 operational factors, ignition being the most important followed by carburetion.
gbritnell
