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[sedyna]

i was wondering what the compression was on my bike... i want to check it myself before i bring it back to the dealer for loss of power...again... i dont need the ratio just the factory specs of what the gauge should read... thanks alot... Jon

[skyhook]

Don't know what the factory spec is, but I ran the numbers through a compression calculator.  If you disconnect the compression releases, I'd expect the guage to read 180 to 185.

[grc]

Don't know what the factory spec is, but I ran the numbers through a compression calculator.  If you disconnect the compression releases, I'd expect the guage to read 180 to 185.

Actually, due to the cam timing you will find the cranking compression to be significantly higher with the compression releases deactivated.  That's the reason releases were added to the 110's.

Rough estimate:  200-220 psi with the compression releases deactivated, closer to 160 with the releases working.

Jerry 

[skyhook]

Yeah, I've seen those numbers posted on this board before.  I don't understand how it could be so high.  I'm using the calculator that I used on my last build, and theoretical was within 2psi of actual.  4" bore, 4.375" stroke, 0 deck height, .045" head gasket, 95cc chambers, 25* intake close, 2cc valve reliefs, around 9.3 compression.  Am I missing something?

[gremlush]

2007 {springer} CVO manual says 200-220 and 130-170 releases open. Have not check mine YET ,been very busy as usual ,John Andrews sent me the 32 cams and is sending the 54s in a week or so. They have not got them done ,YET .  Will be trying the 54s in a 2007 dresser ,bone stock {96"} except for slip-on mufflers. Dewey

[sedyna]

i checkd it as is with the compression releases in.. front jug 150 rear was 140.. plugs were really white..

[Dan_Lockwood]

i checkd it as is with the compression releases in.. front jug 150 rear was 140.. plugs were really white..

Make sure your throttle is wide open during the test.  Without the butterfly open there is no air to compress.

[skyhook]

Has anyone checked cranking pressure with acr's turned off?  The numbers in the manual seem high to me.  On the other hand, that might explain the high number of head gasket failures.

[grc]

Has anyone checked cranking pressure with acr's turned off?  The numbers in the manual seem high to me.  On the other hand, that might explain the high number of head gasket failures.

Probably not affecting the head gasket failures, but those high cranking pressures will sure eat up starters.  And I have seen cranking compression numbers posted somewhere on this forum with the ACR's bypassed, 200-220 psi is correct.

Jerry

[rednectum]

skyhook , to answer your question-----------early closing cams.

[Chief]

Has anyone checked cranking pressure with acr's turned off?  The numbers in the manual seem high to me.  On the other hand, that might explain the high number of head gasket failures.

I checked mine not too long ago. 155 ACR on and 213 ACR off.

[skyhook]

maybe I'm not using the right numbers...110", 95cc heads, flattop pistons, 25* intake close, .045" gasket...more like 185ccp...again I ask, what am I missing?

[rednectum]

maybe I'm not using the right numbers...110", 95cc heads, flattop pistons, 25* intake close, .045" gasket...more like 185ccp...again I ask, what am I missing?

the 110 has 95 cc heads and .045 gasket?  sounds like hd should be asking what they are missing!!!!

[skyhook]

A pro head porter named john sachs measured a set of cvo 110" heads and they were 93cc and the new screamin' eagle catalog lists 110+ and acr performance heads as 95cc.  That's why I thought the cvo heads were that size.  HD usually uses thick gaskets also.  Sorry if I come off as "know it all".  I'm just trying to understand the parts stack up that could equal 200+ ccp in these motors.

[rednectum]

A pro head porter named john sachs measured a set of cvo 110" heads and they were 93cc and the new screamin' eagle catalog lists 110+ and acr performance heads as 95cc.  That's why I thought the cvo heads were that size.  HD usually uses thick gaskets also.  Sorry if I come off as "know it all".  I'm just trying to understand the parts stack up that could equal 200+ ccp in these motors.

after that info, so am i!! its gotta be the cam. surely hd doesnt use domed pistons these days of EPA?  hey man, im trying to learn also, keep it going.

but look at that 25 intake close----- i think thats your answer. no bleed off, and i bt the motor make good tq early and falls on its ass around 3800 rpm?