[T3] Crate running better...

[Keith Park]

I don't have a boroscope but the motor has to come apart anyway due to a
bearing issue, and I get a good cloud of oil smoke when I start it cold.

In looking at the screw heads, this motor doesn't look like its ever been
apart, nothing else on it gave any indication that it was anything but
virgin and with only 32Kmi on the car, I believed it.  It IS possible though
that it came out of another car that had flat tops, this was a delivery
vehicle so it has many work hours but when I ran the 87 octane in it to move
it down the road a couple miles it would knock and ping VERY easily, much
more so than a flat top engine would so I suspect the domies are in it.

Your right though, domies generally have compression around 140-150

Keith


> Question, if the compression is low because the rings are worn, does the
> compression RATIO start to come down too?  In other words, are worn out
> domies as sensitive to gas octane as good ones?

The functional compression ratio also varies with the RPM and goes up 
as engine speed increases. This is because there is less time for 
leakage and less time for heat to soak into the head and piston 
crown. From the numbers you gave, however, my guess is that you have 
pretty normal P/Cs in there. Otherwise, I'd expect some of your 
pressures to be higher. They never all wear down together. 

What you show looks like a couple cylinders with normal pressure and 
a couple with poor compression.

Any chance you have a borescope at work that you could slip into a SP 
hole and take a look?

-- 
*******************************
Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
*******************************

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