Bob,
Painted on the rough degree lines on the crank pulley on Friday night
(thanks for the idea Glen!). On my 1275 at least, the circumference was
38cms, or 1.05cm per 10 degress, and given it was hard to get my tiny paint
brush in there, I'd say my lines are close, but not perfect. Anyway, fired
it up and found my new 23D was running nearly 40 degrees advance over 4000
rpm. No wonder the little bugger was really pulling hard!! I then set the
static timing back to about 1-2 degree advance, which gave me about 28-30
degrees max advance at the high end. It doesn't pull quite as hard as
before, but the engine will probably last much longer! Since my longblock
is 1974 original, I figure my compression is probably 8.0 to 1, so I should
be okay. Thanks again, I would not have thought of checking it on my own,
and a few months down the road, probably would have gotten the chance to
price new pistons!
Coastie Bob
'74 Midget
'90 944S2 Cab
>Yeah, do check that out, just for peace
>of mind. It's too easy to run around
>"overadvanced" at the top and not realize
>it or run around with the wrong spring in
>the SU, due to increased "breathing" over
>stock, as provided by "tuning" changes for
>increased VE at higher rpm which normally calls for a reduction in
>"total"
>timing. Repairs for such errors, should
>they go undetected over time, are as you know, not inexpensive. I am
>also assuming the dizzy's curve was designed
>for the "stock" engine's VE curve as dictated by the stock camshaft
>profile, etc.
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