Lets talk Cold Cranking Pressure
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Tourer
Joined: Apr 2010
Posts: 461
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From: Yale, MI
Lets talk Cold Cranking Pressure
I rebuilt my top end this year. CCP seems to be very important with Harleys in getting them to run correctly with specific cams. I never checked my CCP untill I had a problem and wished I would have before my oil pump broke. Every one talks peek CCP but what about the 1st stroke and the 2nd stroke pressures, I peeked in 3 strokes.
1st stroke 140
2nd stroke 165
3rd stroke 192
Both cylinders were spot on same.
Are these pressures good, normal for my cam and Compression aprox 11:1? Pressures didn't seem to change whether the motor was warm or not.
Jim
1st stroke 140
2nd stroke 165
3rd stroke 192
Both cylinders were spot on same.
Are these pressures good, normal for my cam and Compression aprox 11:1? Pressures didn't seem to change whether the motor was warm or not.
Jim
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Joined: Feb 2007
Posts: 7,663
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From: Northeast Ohio
It is only perfect if that is what the cam wants. 192 is a good number for an easy starting engine, and for the cams you are using at 11:1 it is just where you want to be.
My 120 had ccp of over 220, which was perfect for the cams and build. My 107 had a ccp of 205 which again was perfect for the cams and what I wanted to get in the way of torque from the build. My 103 has a ccp of a little over 190, again perfect for the build and cams.
You could put cams in you engine with less duration and overlap and drive ccp higher getting more torque earlier in the rpm range, or go with bigger cams and lose ccp and end up with a dog on the bottom end.
190 is a nice round number, but the point of all this is for those still learning - the ccp will vary depending on what your goals are.
My 120 had ccp of over 220, which was perfect for the cams and build. My 107 had a ccp of 205 which again was perfect for the cams and what I wanted to get in the way of torque from the build. My 103 has a ccp of a little over 190, again perfect for the build and cams.
You could put cams in you engine with less duration and overlap and drive ccp higher getting more torque earlier in the rpm range, or go with bigger cams and lose ccp and end up with a dog on the bottom end.
190 is a nice round number, but the point of all this is for those still learning - the ccp will vary depending on what your goals are.
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Joined: Dec 2007
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Wholeheartedly agree with Dalton.
9 times out of 10, we are in the 195-200 psi range here.
We check via battery charger in place, and 8 complete cranks, and we key in on how the first strike sweeps the needle.
Scott
9 times out of 10, we are in the 195-200 psi range here.
We check via battery charger in place, and 8 complete cranks, and we key in on how the first strike sweeps the needle.
Scott
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