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Compression?


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Well I went and bought a tester. I checked mine and it was 115-120 on both cylinders. Way better than 90 psi with the other tester.

 

Will check my friends later tonight. They both said that your replies were wrong about 80 psi being too low. You have been right on everything else so far so I knew something was up.

 

Is 120psi better or should a head that is shaved .030 have more?

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Well I went and bought a tester. I checked mine and it was 115-120 on both cylinders. Way better than 90 psi with the other tester.

 

Will check my friends later tonight. They both said that your replies were wrong about 80 psi being too low. You have been right on everything else so far so I knew something was up.

 

Is 120psi  better or should a head that is shaved .030 have more?

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No offense but I think your friends don't have a clue as to what they are talking about if they say that

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Will check my friends later tonight. They both said that your replies were wrong about 80 psi being too low. You have been right on everything else so far so I knew something was up.

 

Yep, your friends don't have a clue and you were right to ask for help here instead of relying on them. A stock bore and port with a fresh top end should be in the 125-130psi range @ sea level. 120 psi sounds about right because of the elevation but I am not sure how much the .030 mill increases compression. I seem to remember (not positive here) that a .030 mill job is pretty close to an aftermarket head with 20cc domes. I might be off on that but I think I read is somewhere. I know my buddy with 20cc domes on a fresh top end, .060+ bore, stock port is running 165psi @ sea level. You might be a little low but I wouldn't worry about it, doesn't sound drastic enough for a rebuild yet. Now your friend that was running 80psi (should go up to about 105 with new tester if it was accurate) might need a rebuild sooner than later if that is stock port work.

 

If 80 psi were enough to run a Banshee, you could literally start it up by pushing the kicker with your hand instead of kicking it

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