pushrod length and base circle

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Nov 2, 2011 | 07:56 PM

rdkonkel

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From: Minnesota

pushrod length and base circle

just wondering if I could measure the base circle of my stock cam vs. my new smaller base circle cam and just minus the difference to get pushrod length.

I would have a 1.550 stock cam
new cam is 1.530
diff of .o20 (radius is .010 shorter)
Stock pushrod length is 7.4
minus .010
new pushrod should be 7.390
Correct? if not, what am I missing?
Seems a lot easier than anything else

Nov 2, 2011 | 08:02 PM

zipster

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From: Celina, Texas

Should add .010, if you are .010 lower in the lifter bore, you need to add .010 to the pushrod.

Nov 2, 2011 | 08:26 PM

rdkonkel

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From: Minnesota

Yeah, without having it pencil'd down and calculator'd i missed that. The few beers isn't helping with my math either. Thanks

Nov 2, 2011 | 08:57 PM

joecar

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From: So.Cal.

You will be told to measure for the required length.

Nov 2, 2011 | 09:38 PM

ZeeOSix

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Quote:

Originally Posted by rdkonkel

just wondering if I could measure the base circle of my stock cam vs. my new smaller base circle cam and just minus the difference to get pushrod length.

If nothing else has changed in the valve train and no head work or new head gaskets, etc; then it should theoretically work by finding the difference in cam base circle radius and doing the math (correctly

) - then adjusting the pushrod length accordingly.