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Bug53 Samba Member
Joined: February 22, 2021 Posts: 743 Location: Pawcatuck, CT.
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Posted: Tue Feb 25, 2025 2:02 am Post subject: Cam Timing Question |
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I'm finnaly putting together my second car which is going to be a daily driver and not too exotic.
78 x 88 (1900)
Stock heads.
8.6 compression.
A pair of EMPI 40 IDFs.
Web 86a cam. Std. engle gear.
1:3 rockers (they are giving me around .456 at the valves.)
Just for the hell of it I threw the degree wheel on it and my findings are strange.
At .050 lift as prescribed the intake and exhaust valves are opening around 6-7degrees advanced but the puzzler is that following the same procedure by measuring at .050 lift the valves are closing right on the mark where they are supposed to be within 1 degree.
Spec.'s are 18 and 54. I'm getting 25 and 54.
My plan is to run it.
What are my pros and cons? _________________ Never blame lazy people, they didn't do anything. |
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bugguy1967 Samba Member
Joined: January 16, 2008 Posts: 4368 Location: Los Angeles, CA 90016
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Posted: Tue Feb 25, 2025 9:50 pm Post subject: Re: Cam Timing Question |
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Seems like you have base circle runout. If the .050” numbers are fine, then it matches well enough. _________________ "A petrol engine can start readily, run smoothly and give every appearance of being in good order, without necessarily being in good tune." - Colin Campbell, "The Sportscar Engine" |
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modok Samba Member

Joined: October 30, 2009 Posts: 27687 Location: Colorado Springs
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Posted: Tue Feb 25, 2025 10:34 pm Post subject: Re: Cam Timing Question |
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timing card data is at the lifter, not the valve.
I know it says valve on the cam card, but it always has said that and it's always been wrong. |
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Bug53 Samba Member
Joined: February 22, 2021 Posts: 743 Location: Pawcatuck, CT.
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Posted: Tue Feb 25, 2025 11:43 pm Post subject: Re: Cam Timing Question |
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| modok wrote: |
timing card data is at the lifter, not the valve.
I know it says valve on the cam card, but it always has said that and it's always been wrong. |
As always you have one of the logical solutions.
Thx. _________________ Never blame lazy people, they didn't do anything. |
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