Its a good news/bad news day. The bad news - I got out
my compression tester to confirm that my Mazda
parts-for-Triumph-hauling truck does in fact have a blown
head gasket. Rats...and I was getting ready to blow my money
and time on a front-end rebuild. Anyway since the tools and
sun were out, I tested the compression on the Triumph. The
good news - measured 185 lbs/sq.in. on all four cylinders -
no deviations, which is good, but why so high? The manual
lists 9:1 as the compression ratio. Tell me if I'm figuring
this right:
Atmospheric pressure at sea level about 15 lbs/sq.in.
9:1 compression ratio, so up to 135 lbs/sq.in. Add a few
additional lbs for the volume of air drawn in by the inertia
of the air mass filling the cylinder, and I figure 150 should
be about right.
When the library opens Monday, I think I'll go educate myself
on this.
Cliff Hansen
1966 TR-4A CTC 64615L
Red, rough, running
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