I went over to my buddies machine shop and we cc'd my head, i thought it was a 22cc head, turns out to be 19cc. I want to set the cr to around 11 to 1 or as high as possible to still run 93 octane. I think if i get a flat top piston it will be very close. Anyone else have simular results with newer hf motors?
At 19cc head volume is too large to get to the compression you want.
Mill the head OR go to a 14cc.
I think it would be easier for you to buy a clone 14cc head ( they cost 20 bucks ) and do some porting yourself. But If you have a friend with a mill then 19cc cut down is an alternative for you.
I am unfamiliar with a 19cc head but off the top of my head they best you can get with a flat top in that case is only around 9:1.
Mill the head OR go to a 14cc.
I think it would be easier for you to buy a clone 14cc head ( they cost 20 bucks ) and do some porting yourself. But If you have a friend with a mill then 19cc cut down is an alternative for you.
I am unfamiliar with a 19cc head but off the top of my head they best you can get with a flat top in that case is only around 9:1.
Check the compression ratio calculator on nr-racing.com, it will answer every question regarding heads,milling,and compression!
Use the excel file, as the pdf no longer works....
http://www.nr-racing.com/documents.htm
Use the excel file, as the pdf no longer works....
http://www.nr-racing.com/documents.htm
an 18cc head with a flat top puts you at 9.8:1 so you'll be less than that with your 19cc head. it'll do fine on 87 pump gas. i was running 87 on my old clone with a .265 modified cam, 18cc head, 1.3 rockers, flat top and all the other crap. basically the same shit you plan on doing.
links to screen shots of the shit from NR if you're feeling lazy.
http://www.oldminibikes.com/forum/a...66d1233487289-billet-rod-help-asap-chart1.jpg
http://www.oldminibikes.com/forum/a...gines/6867-billet-rod-help-asap-chart2-2-.jpg
links to screen shots of the shit from NR if you're feeling lazy.
http://www.oldminibikes.com/forum/a...66d1233487289-billet-rod-help-asap-chart1.jpg
http://www.oldminibikes.com/forum/a...gines/6867-billet-rod-help-asap-chart2-2-.jpg
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Every .010 off a 22cc head raises the compression roughly 9/10 of a cc.
Your head is different than a 22 so I am not sure what that all adds up too.
Measure your bump clearence . My older Lifan is .045 in the hole, and yours ?????
You want about a .035 or so ( this includes .010 for the head gasket ).
What this means is you might want to have the block decked to get the bump clearence dead on.
Your head is different than a 22 so I am not sure what that all adds up too.
Measure your bump clearence . My older Lifan is .045 in the hole, and yours ?????
You want about a .035 or so ( this includes .010 for the head gasket ).
What this means is you might want to have the block decked to get the bump clearence dead on.