I think you'll be fine with what you came up with. It isn't worth agonizing over a stock EEC spec cam off by a couple degrees...
Glen
--Previous Message--
: The contradictions you found do not
: surprise me. I was lamenting to a
: friend how British cam grinders seem to
: universally overlook providing complete
: data with their product which leads to
: different methods for setting and
: checking. Consider the Crane document
: you posted the link to earlier. Almost
: universally, U.S. cam grinders provide
: the type of cam card that is show in
: the Crane assembly instructions. The
: card specifies clearly at what angle(s)
: of crank rotation their specified
: 0.050" of lift occurs. If that
: were available with new cams for these
: British engines there would be no
: possibility of mistakes.
:
: 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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