[DeTomaso] Valve cover sound, strangest question of the day?
Boyd Casey
boyd411 at gmail.com
Sat Apr 12 17:03:14 EDT 2014
Aside from contact issues or something actually being broken , Stamped
steel valve covers or covers made from aluminum sheet metal will not
insulate the sound as well as thick walled cast aluminum covers. You can
use a mechanics stethoscope to listen for and pinpoint any metal on metal
sounds. It's relatively simple to change the valve covers and is certainly
worth the trouble if you think there is even a remote chance that there is
contact with the valve train and the cover. Back when I had an old Harley
Pan Head they had felt pads that you put inside the valve covers to reduce
the valve noise. They made a very substantial difference in reducing the
noise. I think they have felt or rubber pads for auto engines valve
covers. It's something you could look into if there is nothing mechanically
wrong.
Boyd
On Sat, Apr 12, 2014 at 12:15 PM, Mike Thomas <mbefthomas at comcast.net>wrote:
> 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
>
>
> _______________________________________________
>
> Detomaso Forum Managed by POCA
>
> DeTomaso mailing list
> DeTomaso at poca.com
> http://poca.com/mailman/listinfo/detomaso_poca.com
>
>
> _______________________________________________
>
> Detomaso Forum Managed by POCA
>
> DeTomaso mailing list
> DeTomaso at poca.com
> http://poca.com/mailman/listinfo/detomaso_poca.com
>
-------------- next part --------------
Aside from contact issues or something actually being broken , Stamped
steel valve covers or covers made from aluminum sheet metal will not
insulate the sound as well as thick walled cast aluminum covers. You
can use a mechanics stethoscope to listen for and pinpoint any metal
on metal sounds. It's relatively simple to change the valve covers and
is certainly worth the trouble if you think there is even a remote
chance that there is contact with the valve train and the cover. Back
when I had an old Harley Pan Head they had felt pads that you put
inside the valve covers to reduce the valve noise. They made a very
substantial difference in reducing the noise. I think they have felt or
rubber pads for auto engines valve covers. It's something you could
look into if there is nothing mechanically wrong.
Boyd
On Sat, Apr 12, 2014 at 12:15 PM, Mike Thomas
<[1]mbefthomas at comcast.net> wrote:
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:[2]detomaso-bounces at poca.com] On Behalf Of
Mikael
Sent: Saturday, April 12, 2014 8:49 AM
To: [3]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
_______________________________________________
Detomaso Forum Managed by POCA
DeTomaso mailing list
[4]DeTomaso at poca.com
[5]http://poca.com/mailman/listinfo/detomaso_poca.com
_______________________________________________
Detomaso Forum Managed by POCA
DeTomaso mailing list
[6]DeTomaso at poca.com
[7]http://poca.com/mailman/listinfo/detomaso_poca.com
References
1. mailto:mbefthomas at comcast.net
2. mailto:detomaso-bounces at poca.com
3. mailto:detomaso at poca.com
4. mailto:DeTomaso at poca.com
5. http://poca.com/mailman/listinfo/detomaso_poca.com
6. mailto:DeTomaso at poca.com
7. http://poca.com/mailman/listinfo/detomaso_poca.com
More information about the DeTomaso
mailing list