[DeTomaso] Asa Jay's 1985 built 351C Forensics part II
Asa Jay Laughton
asajay at asajay.com
Sat Nov 27 21:52:26 EST 2010
Today in Asa Jay's garage, we take a closer look a the weirdness we
found in number 2 cylinder yesterday. My focus was -only- on cylinder
number 2. I did not disassemble any more of the engine that just this
cylinder. The rest will come later. For today, I inspected the head
surface, intake gasket, head gasket, removed the two valves from the
cylinder, removed the piston and inspected both it and its bore.
The photos are here:
http://www.351c.info/gallery2/v/asajay/1985buildforensic/
You'll probably want to pick up the story at this point:
http://www.351c.info/gallery2/v/asajay/1985buildforensic/PB270022.JPG.html
The intake gasket shows that it was totally sealed against both the
intake and the head. The seal is a type that also blocks off the
exhaust gas recirculation port.
As Doug Braun pointed out, he thought he saw some deterioration between
cylinder 1 and 2. I closely inspected this area and he was correct.
On the head, there is a thin buildup of carbon in a small triangular
area between the cylinder sealing rings. On the gasket, there is a
corresponding depression. It very well may be there was a cylinder to
cylinder leak between 1 and 2. But if that were they case, why would
only one cylinder show the nasty carbon buildup? Could it be due to the
firing order?
Next I removed the intake and exhaust valve on cylinder number 2. They
both look fine. No indication of leaking past the valve guides, which
by the way have a positive seal on them (forgot to take a photo). A
nominal amount of carbon buildup on the intake and the exhaust appears
good as well. The ports in the head are also clean.
The piston appears to be in one piece, no cracks I can see. The
compression rings also appear to be in good shape, they both still have
spring left in them though they are very shiny on the edge. They do not
appear to be broken. The lands on the piston appear to be okay though
I've not removed the rings yet. The oil seal has a lot of carbon on it
and is nearly stuck in place. It does not appear to be broken and does
move some, but you can definitely tell it has some buildup.
The cylinder wall looks good. No cross-hatching visible anymore. Very
shiny. I can't perceive any cracks though it may take a dye or
magnaflux test to know for certain. This block was originally bored
.030" over so I most likely won't use it again for anything. I may try
to find a machine shop to hack it into sections for me for illustrating
other internal stuff. :)
One thing to note is the condition of the rod bearings. I've only
removed one mind you, but it looks terrible. It appears to have taken
in some very small debris, the kind that can get through the pump and
bypass the filter when cold.
Alrightly, take a gander at the photos and see what you think.
Asa Jay
Asa Jay Laughton, MSgt, USAFR, Retired
& Shelley Marie
Spokane, WA
******************************
http://www.racingagainstautism.com
http://www.teampanteraracing.com
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