Head Gaskets.
François has had two head gaskets fail on him with 365 heads,
and we've been working on finding a replacement that works. We're still
collecting data, and if you have anything to add, please e-mail me. Collecting this
information will help others before they encounter the same problems,
and may force the suppliers to take note and make changes with their
products. No one wants to pull a head again on a V-12 Ferrari engine
because of inferior head gaskets!
There are three different designs of head gaskets available out there,
but we've had two of them fail on us.
Here's a gasket that cam off of a 365GTC/4. It looks original, and does
not have a silicone o-ring type gasket found on some of the modern head
gaskets.
Upon closer inspection, however, we found an old engine builder's trick
at work on this gasket. Yarn was laid on top of this head gasket
surrounding all the water passages. François was taught this
trick at the factory, and I've seen him use this technique on gaskets
before the silicone o-rings were introduced in the modern head gaskets.
Seeing this yarn has led us to believe this engine may have been apart
once before. Whoever assembled this head knew the same tricks as
François, whether it was at the factory or in some other shop is
anyone's guess.
This gasket was purchased from an Italian manufacturer. It measured,
and looked very similar to the "original" one pictured previously.
It, however, failed to seal the water passages when the head was
torqued down. There was not enough "crush" between the cylinder walls
and the gasket to seal the water passages. Ferrari cylinder walls sit a
couple thousands proud of the block deck, and crush the head gaskets a
little more at the gasket's fire ring. The fiber portion of the gaskets
should seal sufficiently once the cylinder walls seal against the steel
rings. These Italian gaskets did not. After the first failure, we tried
spraying a second set with spray RTV with little improvement. The
coolant still leaked out between the head and the block without any
pressure to the system.
On another car, a 365GTB/4 Daytona, a recently installed headgasket
failed. This gasket is another design with a modern o-ring impregnated
around the water passages. The symptom was finding water in the oil.
This gasket is widely available from parts suppliers in the States, and
I've seen them before at other shops, but we're surprised this one
failed. You can see the RTV residue on this gasket along with the
flattened silicone o-ring that was supposed to seal the water from the
oil passages. François has probably installed thousands of
gaskets, so i would doubt operator error in this failure. Besides, if
there was a mistake in the installation, the gasket would not have
taken several months to fail.
A third gasket was purchased to try on our 365 engines. This gasket
comes from Australia and although has the silicone o-ring, its seal is
more thorough.
The silicone o-ring in this gasket surrounds more of the water
passages, and may do a better job at sealing the head. We've installed
this gasket on the C/4 and so far, have not seen any leaks. The Daytona
is next, and we'll see how things go. Hopefully we'll get to the bottom
of this and will find a gasket we can all rely on!
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