 Rocker Geometry Questions |
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| tornik550 |
 Sep 22 2011, 09:09 PM
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Senior Member  Group: Members Posts: 1,248 Joined: 29-January 07 From: Ohio Member No.: 7,486 Region Association: None  |
I have read Jake's valvetrain geometry article however I want to be very clear a bout a few things before I proceed.
The advertised lift of my cam is .503. I gone through the steps in the article many times, adjusting the pushrod length however the closest that I can get to the advertised lift is .478. That' right on the edge of the 5% rule. I have not checked my exhaust lift cause my cam does not have a split duration. Since I am on the very edge of 5% rule on the intake valve, I will surely be out of 5% with the exhaust valve. Are my numbers acceptable? If the numbers are not acceptable then what do I do since I cannot get the lift any closer to the advertised numbers. |
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| Jake Raby |
Sep 22 2011, 09:17 PM
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
Even if you don't have split duration you still have to check the exhaust side because you never assume anything in engine building and yiou quantify everything.
Check lift at the lobe and multiply that times the rocker ratio. That will be the highest possible number that you can attain lift wise. This cam sounds like an 86C, if so it should be .507 at the intake valve, you'll be hard pressed to see more than .490 out of the exhaust. |
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