In my case, such a card would probably not help as there is either something wrong with my cam OR it is not a factory cam. My confusion is that there is a discrepancy between the LCA for intake #1 and setting the "straight up" overlap as described in the factory manual and explained by you.
You'll remember that I created the lift chart for my cam. When the data is mirrored horizontally and superimposed it is immediately apparent that this can does have a symmetric profile. Therefore, finding LCA for intake #1 as I did is a valid checking method... if you know where the LCA is supposed to be positioned. As you pointed out, if the LCA is properly positioned, the straight up overlap should occur at TDC. My underlying frustration is that with my cam it is not possible to achieve that setting.
You will remember that earlier I also posted a link to Paul Geithner's list of cam data. On that list is a possible answer to what I am seeing. Isky's HR-8-003 cam is supposed to be a regrind of the factory profile. However, there are some differences. Paul's value for the lift does not match the value Isky lists which is the same or slightly less than the OEM cam. More importantly, the Isky cam lists intake #1 LCS as 112 degrees, not the OEM 110 ATDC. After tinkering all yesterday morning I found a setup where the I have the LCA at 110 ATDC resulting in overlap at 2 BTDC... a 2 degree difference from straight up. If I have the Isky cam (possible) then moving the LCA to 112 would put the straight up overlap right at TDC. Thus, the measurements I took yesterday along with the lift measurements made earlier are consistent with this cam being a regrind from Isky. I did not observe any marks on the cam that indicated a regrind.
I have decided that if I do not receive contrary responses from people I emailed directly, I am going to stop spending any more time on this and leave things set for the LCA at 110 and overlap at 2 BTDC. That will be close and once the chain stretches it will be almost spot on. This will retard the cam a couple of degrees from where it was before the engine work so the engine is likely to feel different... but it was going to feel different after the rebuild anyway!
Doug L.
--Previous Message--
: Now in another later edition Autobook I
: found listed the same event specs,
: measured @ a ROCKER clearance of .050,
: which is very much different than .040
: tappet rise...
: FWIW
: Glen
:
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