Guest V8ish Posted November 14, 2008 hey guys, 1st post! Long story short......running a standard 1.9 8v (as far as I know) with bike carbs. A RR session showed 122bhp at the fly. A little dissapapointed the operator said I should do a compression test, which I did hoping for at least 10 bar on each and a close grouping....the results surprised me. 1 - 14.5bar/210psi 2 - 14.5bar/210ps 3 same 4 - 14.4 bar Pleased that they are almost identical but worried it is too high...should I? I assume the head must have been skimmed at some point, what are the consequences of having such high compression. The next plan is a timing and fuelling set up, but a bit of work to lower compression if you guys think its too high (double head gasket as a bodge?????) Thanks Share this post Link to post Share on other sites
welshpug 1,657 Posted November 14, 2008 sounds spot on for a very healthy engine, I wouldn't be worried about them, was it running lean or rich at all? Share this post Link to post Share on other sites
Guest V8ish Posted November 15, 2008 sounds spot on for a very healthy engine, I wouldn't be worried about them, was it running lean or rich at all? Yeah it was, apparently it has the wrong jetting? Why you ask? Share this post Link to post Share on other sites
rapidcossie 0 Posted November 15, 2008 higher comp should give you more power, not less Share this post Link to post Share on other sites
Anthony 1,003 Posted November 15, 2008 Accuracy of compression testers, particularly cheap ones, seems to be somewhat variable so I wouldn't take the numbers too literally unless it's showing considerably higher compression than similar engines. Important thing is that all four cylinders have similar compression and that you're getting a high number - 180-200psi is what I usually see on a heathy engine. If accurate, 122hp at the flywheel isn't too bad to be honest, particularly if it's never had a rebuild and the carbs aren't jetted properly - it's generally accepted that they rarely left the factory with the claimed 128hp and if the carbs aren't setup properly either... Share this post Link to post Share on other sites
Guest V8ish Posted November 15, 2008 Thanks for the replys... OK, I have borrowed another tester....an expensive 1 which has showed much more reasonable results. these are dry/wet figures 1 - 10.4/11.3 2 - 10.7/11.5 3 - 10.3/12.1 4-10.1/12.1 sounds more like it. What are your thoughts on these results?? Just goes to show an £8 BIN on Fleabay wasn't worth a penny! Share this post Link to post Share on other sites
welshpug 1,657 Posted November 16, 2008 Veery even, certainly nothing to be worried about, seems like your RR operator didn't want to set your car up properly Share this post Link to post Share on other sites
