NickisGod Posted December 21, 2009 Report Share Posted December 21, 2009 I was reading on the noss website about compress and elveation and the chart, somehow it dosnt make sence. I live in clarence center ny, we are about 594.01 ft above sea leave my dome size is at 19cc. According to noss i would land in the 175psi+/-. My compression is only 140psi on both sides and i was wondering what others cubs owners run? Last summer i was running c-12 in my bike and it ran great, later in the fall i used 93 and run just as strong. Sea Level 1000' 2000' 3000' 4000' 5000' 18cc 197 178 171 170 165 145 19cc 183 167 160 158 152 137 20cc 169 156 149 146 140 129 21cc 156 145 138 134 128 121 stock 130 125 118 112 106 100 so, what are you guys running? Quote Link to comment Share on other sites More sharing options...
wacko2000 Posted December 21, 2009 Report Share Posted December 21, 2009 Sorry alittle off topic but where is clarence center ny?? When was the topend built last on your shee? Quote Link to comment Share on other sites More sharing options...
NickisGod Posted December 21, 2009 Author Report Share Posted December 21, 2009 its a suburb of buffalo, and the engine was build in august of 09 Quote Link to comment Share on other sites More sharing options...
RadarRacing Posted December 22, 2009 Report Share Posted December 22, 2009 You didn't say bore size or what motor size. If you have a 65mm bore stock stroke cub you might have 140-160 psi with 19s. I've ran 18,19,20 cc domes all in a 68 bore cub dynoed those, raced them and I will tell you going from 140 psi to 180 is a big jump in power. There are numerous ways you could read low. Too thick of a base gasket is a common one, poor gauge reading from an auto parts store gauge is another one that's common, engine needs to be warmed up. U Need to use a good snapon gauge if you can and hold the throttle wide open and kick hard a few times on a fully warmed up motor. I rarely use a gauge, I go by my trapped volume measurement. Quote Link to comment Share on other sites More sharing options...
bansheeseat$$ Posted December 22, 2009 Report Share Posted December 22, 2009 Those numbers you got are for a small bore reading.I am at 4500 feet with 18cc domes on my 68mm bore cub and my compression is 185 psi and at sea level I am at 215 psi. Quote Link to comment Share on other sites More sharing options...
rubberneck Posted December 22, 2009 Report Share Posted December 22, 2009 As stated earlier, that chart only estimates compression for stock stroke and bore motors. My 421 i ran 20cc domes and kicked 185 psi at sea level. Quote Link to comment Share on other sites More sharing options...
No Limit Powersports Posted December 22, 2009 Report Share Posted December 22, 2009 Those estimates are for stock cylinders not cubs. A cub motor has a completly different transfer, intake and exhaust setup. A 19cc dome should make more than 140 on the smallest cub motor I would like to know how exactly you are doing the test and what kind of gauge you are using, then you need to do a squish test. Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted December 22, 2009 Report Share Posted December 22, 2009 Stock port cub 20cc domes 185 kicking sea level 68mm bore,I have also had custom cut domes that gave weird readings did you purchase everything as a package or pick the domes up seperate or special.Did you check the squish Quote Link to comment Share on other sites More sharing options...
dajogejr Posted December 23, 2009 Report Share Posted December 23, 2009 bansheestang hit the nail on the head. I run 20cc domes in my 10 mil cub with an HJR drag port, mid to high .050's on the squish and I still get 185 Cranking PSI on a good quality Snap On gauge. Quote Link to comment Share on other sites More sharing options...
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