[DeTomaso] Valve cover sound, strangest question of the day?

[Mike Thomas]

If you are talking about the cast aluminum valve covers with DeTomaso on the
top, and you are running a set of aluminum roller rockers, you may be
experiencing interference between the rockers and the baffles in the valve
cover.  When I had my motor built in '07, I had my builder install a set of
aluminum roller rockers (don't recall the brand without digging out my build
sheet) which were a rather blocky casting.  Mine are blue (not sure if that
means anything, FoMoCo?), but have seen the same from other manufacturers.
There was quite a loud ticking that I thought to be much more serious than
the truth.  What was happening was that the corners of the rockers were
contacting the angled portion of the oil fill and vent baffles in both valve
covers, and I had to remove the covers, remove the baffles, relieve that
area of the baffle with a slight peening, and reinstall them (never just
take them out and toss them!!).  You can check easily by removing the valve
covers and looking at the baffle, or the corner of the rocker, and you'll
see a wear spot.

The strange part about this one is that you don't hear the noise at first,
likely because the rocker doesn't leave contact with the baffle until there
is a little wear in the softer aluminum material on the rocker, and the
baffle is scratched a bit, then the noise is much like a stuck lifter or
bent push rod as it's coming from the top of the motor.  Also, trying to
peen or relieve the baffle while it is still in the valve cover is very
difficult as it is very easy to bend the baffle so it no longer stays seated
in the cast lip in the cover meant to keep it in place.  You could possibly
do this with a Dremmel tool with a small grinding head.  I'm not sure if
polishing off the corner of the rocker is a good idea for balance or
strength issues with the rocker.

One local member recently had a bunch of us up to pull his motor.  Said
there was this horrendous whacking noise coming from his brand new build.
The builder, located in California, told him the only way he'd check it out
was if the owner pulled the motor and shipped it back to him.  So, we have
the motor out an on the pallet, just before we were going to strap it down
and wrap it, and I mentioned to the guy "let's pull a valve cover and take a
look".  Sure enough, that was all it was.  He pulled the manifold later to
be sure there were no valve lifter issues or other obvious problems, but all
else seems to be in good order.  He was completely embarrassed to have had
pull his motor for such a simple fix.

Good luck.
Mike Thomas
VP, POCA
VP, Panteras Northwest
Yellow '74 #6328



-----Original Message-----
From: DeTomaso [mailto:detomaso-bounces at poca.com] On Behalf Of Mikael
Sent: Saturday, April 12, 2014 8:49 AM
To: detomaso at poca.com
Subject: [DeTomaso] Valve cover sound, strangest question of the day?

This may seem like a strange question, but has anyone experienced a change
in the mechanical sound of an engine by switching valve covers? I replaced
the Ford Racing chrome covers this winter with fabricated alu valve covers.
Man, they look good. But at idle, now I hear more valve train noise than
exhaust noise. Can this be? I can of course have a valve train issue, but I
don't think so.

Mvh/Regards
Mikael


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