bansheefreak Posted March 6, 2009 Report Share Posted March 6, 2009 how did your sqiush test turn out... still not right 157 is too much for stock (22)cc... where you live in kc??? in in so,joco.. Quote Link to comment Share on other sites More sharing options...
badshee1998 Posted March 6, 2009 Report Share Posted March 6, 2009 how did your sqiush test turn out... still not right 157 is too much for stock (22)cc... where you live in kc??? in in so,joco.. hey bansheefreak, i have almost the exact same setup as dustinp except i have fmf sst and he has toomeys and im only bored like .10 over and hes bored .80 over, im running 20cc domes and im at 165psi, and i used acually the same tester he did. will the bore have anything to do with it? oh and i have stock carbs and he has 33s. thats it, what do you think? Quote Link to comment Share on other sites More sharing options...
bansheefreak Posted March 6, 2009 Report Share Posted March 6, 2009 well he got it down some with diff domes but i would wanna know why its so high with stock sized domes.. is he in gardner too??? know how to do a sqiush.. Quote Link to comment Share on other sites More sharing options...
DustinP Posted March 6, 2009 Author Report Share Posted March 6, 2009 well he got it down some with diff domes but i would wanna know why its so high with stock sized domes.. is he in gardner too??? know how to do a sqiush.. I'm in KCK, I went to do the squish, but the soder I had was too thick. I'm gonna get some thinner stuff and try it. Quote Link to comment Share on other sites More sharing options...
DustinP Posted March 9, 2009 Author Report Share Posted March 9, 2009 Did the squish test today - 0.043 in or 1.09mm Quote Link to comment Share on other sites More sharing options...
AWR Posted March 9, 2009 Report Share Posted March 9, 2009 Did the squish test today - 0.043 in or 1.09mm was the exhaust hieght even touched? these numbers are high for a motor that was dune ported(maybe his dune port carries very little duration)not bad mouthing just curious.that thing will pull like mad and layover tuff on bigend.i would be happy with that head to piston clearance though. Quote Link to comment Share on other sites More sharing options...
TPhillips Posted March 9, 2009 Report Share Posted March 9, 2009 was the exhaust hieght even touched? these numbers are high for a motor that was dune ported(maybe his dune port carries very little duration)not bad mouthing just curious.that thing will pull like mad and layover tuff on bigend.i would be happy with that head to piston clearance though. Can you elaborate or explain that? I have cylinders with the same port work and same squish. Quote Link to comment Share on other sites More sharing options...
sredish Posted March 9, 2009 Report Share Posted March 9, 2009 I'm running 21cc domes, FAST Racing dune/play port, bored .080 over, +4 timing in Kansas City around 900 ft. I tested my compression and Im at 175 psi. I heard 165 was cut off for race gas. Has anyone else had similar setup and what was their compression? Jeff thought this was high for my set up but didnt know why. He said to throw some octane booster in and I would be fine. Just wanted to get some other opinions. Has anyone else ran octane booster and at what compression. I am thinking of putting in 22cc domes so I can just run 91 octane. Any Ideas? absolutely, the ONLY octane booster that works for what we need it to... tried and tested on many thumpers, including my 15:1 stroked 450r.... Kemco Octane Booster "Octane boost-fuel additive that really works. 2-16 point increase on octane. Turn a 93 Octane fuel into 101 with 8 ounces per gallon. CONTAINS LEAD! Fouls O2 sensors and plugs cats. Off road use only. " Quote Link to comment Share on other sites More sharing options...
dajogejr Posted March 9, 2009 Report Share Posted March 9, 2009 Sorry if this is already answered.... What brand of compression tester are you using? Does the threads on the compression tester match the length of the threads on a spark plug? Quote Link to comment Share on other sites More sharing options...
2003LimitedBanshee Posted March 9, 2009 Report Share Posted March 9, 2009 I put 22cc domes in it last night and it measured 157. I was told there is suppose to be 10psi difference per cc which should have put me at 165. The compression tester we are using is a snap on, before I used a craftsmen and it said I had 170 with the 21s. Can worn reeds affect your compression? My reeds were about 6ys old and seemed like they didn't have enough resistance. One of them was chipped where the bolt goes through. I put new replacement reeds in it last night(same time I changed to the 22s) I am lower than what I thought I should be. A chipped reed should actually serve to lower your compression. On compression the reeds get "pushed" closed, think of it as the intake valves on your car or 4-stroke. So, if you have a valve hanging open, or chipped, you will not be able to develop the same compression as if you were completely sealed. There is so much debate about dome size and compression. I have a Snap-On compression tester that I trust religiously and I have not kicked below 170 on cold cylinders with 20cc domes at 1982 feet elevation. As far as gas goes, I would recommend mixing also. I ran a mix of Trick race gas and premium for quite a while, ran straight Trick last year because I could buy Trick for within a dollar of premium when I bought it buy the 55 gal. drum. Quote Link to comment Share on other sites More sharing options...
TPhillips Posted March 9, 2009 Report Share Posted March 9, 2009 Sorry if this is already answered.... What brand of compression tester are you using? Does the threads on the compression tester match the length of the threads on a spark plug? The gauge is a SNAP-ON, and the threads are the same lenghts. Quote Link to comment Share on other sites More sharing options...
AWR Posted March 9, 2009 Report Share Posted March 9, 2009 Can you elaborate or explain that? I have cylinders with the same port work and same squish. whats your compression?too much compression dosent allow a motor to rev as high.i try to get 165lbs. of compression with a 17cc dome.thats the combo that seems to work the best for me.cranks seem to last alot longer under 165lbs. also.I built a motor along time ago that had 115lbs. of compression(YOU COULD START IT WITH YOUR HAND)but it would detonate without race gas.ihad the head cut all wrong-too narrow of a squish band and too big of a combustion chamber.it ran decent(just an experiment gone wrong)it was harder to gather information before the internet was available!!so there was much more trial and error. Quote Link to comment Share on other sites More sharing options...
wesw Posted March 10, 2009 Report Share Posted March 10, 2009 (edited) you need to find out if those are jeff specs or noss spec domes. you either have a dome that not cut right for your set of pistons or something you should be pushing that high of psi with 21s. ask what the squish band was cut at and what velocity they were cut at. you dont want to self destruct your motor cause of something really simple. i run 19cc domes on my cub yeah its different motors but get 175 your getting more than me with 21. one more thing you might have a set of cases that are a lil thicker on thiner and throws your stuff off but you have a decent squish so that might be true. bansheefreaks motor the cases are different or something you have to cut the squish narrow to get it to be right it was a pain in the ass. Edited March 10, 2009 by wesw Quote Link to comment Share on other sites More sharing options...
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