Don,
you probably have a regrind and the cam profile may not be stock. The "M13"
is most likley a designator indicating the grind, but it means nothing to
me. Perhaps someone else may have a clue.
You can find out what profile you have if you set it up in the block, and
"map" the lobe with a dial indicator. Plot the readings against the
crankshaft angle about every 5 degrees (closer at max lift) and you will
find the duration and lift of the grind. You can also find the lobe center
angle if you reset and check the exhaust lobe on the same plot.
Hope this helps
Chip
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From: DLMAssoc@aol.com[SMTP:DLMAssoc@aol.com]
Sent: Monday, December 01, 1997 4:36 PM
To: FOT@autox.team.net
Subject: TR3-4 camshafts, what do I have here?
Was the 83mm TR3 camshaft different than the shafts in the 86mm engines?
I have a cam that came with a load of TR3 parts, including a complete 83mm
engine that was apparently ready for reassembly (new piston set, gaskets,
crank, redone head, etc), so I assume the cam was part of that project. I
also have two other cams, one of which I know came out of a TR4A engine,
the
other was probably TR3.
Anyhow, the odd cam came in a cam-sized shipping box marked "M13 / TR3" on
it. The end of the cam is also stamped "M13". It does not appear to have
been in an engine, as the shaft and lobes are still black (bearing areas
are
shiny). It seems to be exactly the same as the other two except that all
the
lobes are approximately 1/8" shorter than the lobes on the other two
shafts.
Neither of the other cams have anything stamped on their ends.
Incidentally, the cam came wrapped in a page from a horse racing results
form from December 4, 1982. That's about the same timeframe the receipt in
the head indicates it was redone. Was anyone selling an "M13" model cam in
the early '80s? Anyone want to bet a grand on Princely Hope to win in the
first at Hawthorne on Dec 4, '82?
Anyway, I'd always thought that TR3-4 cams were all the same. Were the
cams
for the 83mm engines different? Any ideas as to what I have here?
Thanks,
Don Marshall
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