Bob;
You may be right about the T-stat....the motor runs very cool with none.
Regarding my temp gauge, I have compared the readings with an infra-red
thermometer, and the gauge seems to be pretty accurate in the 200-220
deg. range.
I have heard conflicting stories about the effect of over-boring these
motors on operating temperature. The thick-walled early block like mine,
the story goes, ran cooler when bored up to 100 thou, due to better heat
transfer to the water jacket. It would be nice to have an experienced
engine builder comment.
Best regards,
Dave
Subject: RE: [Fwd: Re: Tiger Temp] UPDATE
Jim,
Just a few words in defense of a "breathed on" engine. Most of the
things
done to raise HP output also actually improve thermal efficiency, which
tends to reduce the waste heat the engine has to get rid of. For
example,
increasing compression ratio - at least up to a point. I tend to believe
that most of the reasons for a modified engine running hot are due to
friction caused by, as you suggest, stiffer valve springs, too little
piston
and bearing clearance, etc. Also, it is commonly believed that thin
cylinder
walls from over-boring the cylinder walls makes a motor run hot - which
is
not implausible.
With respect to your alleged heating problem, I surmise from your
experience
so far that you will find that either a) it's the thermostat making your
engine run hot, or b) your temperature gauge is wrong.
Bob
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