Zero Compression 164 (question: engine type?)

[JHertzman@xxxxxxx]

I am boggled by the Zero Compression 164 Arno Leskinen reported on in AD7-178,
and found Abe Kheraz' observations in AD7-179 interesting.

Abe's option #5, "Wrong cam timing, both valves on all cylinders are open in
the compression cycle (possible if belt slipped on both cam)" seems to be out
unless this is the extremely rare two-stroke 164, or possibly a three-stroke.
If it is one of the more usual four-stroke versions (suck, squish, pop, ptui,
suck, squish, pop, ptui-) I would think that unless the valve timing is very
radical having both valves open through the entire 'squish' stroke should have
both closed at the same time through at least part of the 'ptui' stroke,
giving some sort of reading.

The ethnic slur in the woodpile  (or chicken-coop, depending on where you
live) is that cylinder with twenty pounds compression. Except for that, the
obvious answer would be a defective gauge, very common with low pressure
reading problems on Alfas. The stated condition - "An inspection reveals no
bent or broken valves, everything turns as it should, and the pistons appear
to be in the correct relationship to each other" would match Abe's possibility
#3, Holes in pistons, but it would have to be a very small hole on the twenty
pounder. As Abe says, (not likely). Another possibility would be sheared
flywheel bolts- the starter motor spins the flywheel but not the crank- but
again, there is that twenty-pound cylinder. Another remote possibility would
be a broken crank, if the twenty pound cylinder is at the flywheel end. Or
five broken rods, but there should be an obvious clatter.

The mechanical question seems as odd as the possible problem source. "This
person wants to know if anyone has any ideas of what could cause this before
he starts pulling the heads off." That makes sense only if it might be a
problem which could be fixed without pulling the heads off- like the bad
gauge, I suppose.

If it IS true that "There is NO evidence of water in the engine!!!!!!!" then
the no-start could be an ignition or injection problem, but-

Ah- if it was a four cam engine (or a four-cylinder two cam) Abe's option five
is possible, one valve open through the entire squish stroke and the other
open through the entire ptui stroke but not, as he suggested, both open
through the entire squish and thus closed for the entire ptui. With the
standard push-rod V-6 164 one should not get both unbent valves on one
cylinder open at the same time unless half the cam lobes slipped on the
camshaft.

Abe's first line stands: "There has to be more to the story than what it was
revealed." And his last line: "Please report back on your findings." This
can't help being interesting.

John H.

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