Paint Burnt Off Valve Cover?

[AMXguy]

The paint has burnt off the valve cover  directly  behind the right HP manifold on my 440, is this normal?  it's a fresh rebuild and the plugs look perfect so I don't suspect a lean burn heat problem.

My other 440 didn't do it.

[nqkjw]

I'd say it's either too lean or too much backpressure from too restrictive an exhaust system.

[AMXguy]

Brand new TTI 2 1/2" system so I know that's not it.  I'm going to pull the plugs again but they were light chocolate brown last time I did.

[Grec]

Have to ask the obvious... what kind of paint was used on the valve covers? Is the discoloration concentrated all across the cover or just at one place?

As to temp, if you can get your hands on one of those laser or contact temp guages, you could check across all ports to verify that you're not running excessively hot.

Just did mine and seemed to be running about 375 average warmed up well on a hot day when measuring a header pipe right at the flange. It's actually very helpful to know the temps each cylinder is running at in it's own right.

As you said though, easy enough to tell if you've got a lean-burn situation from the plug(s).

[AMXguy]

I used Plastikote Ceramic , and the paint isn't discolored it's burnt off .

I pulled the plugs again and they are a perfect light brown. maybe it happened during my break in and I didn't notice it before.

[Grec]

"I used Plastikote Ceramic , and the paint isn't discolored it's burnt off ."

Ack! Yeah... that's not normal. :-)

I'm stumped as to how it would generate enough heat to do that without you seeing it in the plugs...

[Aussie Challenger]

Could the valve covers had a residual oil stain on them before painting?   

[mojavered]

Possible to post a pic?

[AMXguy]

It was blasted to bare metal, so it was super clean.

I already repainted it so no picture, I haven't driven it since so I'll have to see if it does it again.

It was just a little half moon right behind the closest area of the manifold, I'm hoping maybe it happened on break in before I got everything dialed in.

[Chryco Psycho]

it could be a break in issue , running at 2000 rpm with no air flow will create some heat , I have also seen some mainfolds with casting  flaws inside causing restriction that you would never see ... ever wonder why some cars were faster for no reason !
if you can get an infrared heat sensor you can read different temps in the manifolds , I have seen them as low as $45 

[AARuFAST]

My 383 Gran Coupe convertible runs hot in traffic.
The paint was burned where the exhaust manifold is closest to the valve covers.

I stripped them and painted them with hi temp primer and hi temp orange.

Found out the clutch fan was shot.

If u can hand spin the clutch fan more than 1 to 1 1/4 turn it is time to replace it.

Haven't driven enough to see the results since I only replaced the clutch fan on the 4th of July.

Heading to Carlisle all Chrysler Nationals this weekend will see if new clutch fan remedies the problem.