keithl1967

This is on my '67 Camaro, not my 'vette, but all the same, it is a bit perplexing:

On a whim, I decided to take the temp of my headers...what I found is a bit curious (to me--maybe someone on here can explain why)...

The left bank all read between 285 and 330 degrees (1, 3, 7 are 320-330, with #3 being the outlier)...
The right bank all read about 425-435 degrees (no outliers)...

I'm thinking that #5 could be a miss (although the motor runs fantastic...it's got a definite lope--it should on the Comp XR282HR--and nothing that would have led me to believe I had a miss otherwise)

Why would there be a 100 degree difference in primary temp form one side of the motor to the other?

I should note that the headers are patriot ceramic coated, and the motor is a 406...

Thoughts?

Thanks!

jr73

I had a similar problem on my 68 Camaro, it had a couple of tubes that ran cooler. Now this may not be the case at all on your car but I'll share it anyway. Apparently oil was getting sucked up into my pcv. and into my intake manifold where I got my vacuum from. It fouled a couple plugs and those cylinders by not burning right ran cooler. What I did is install a baffle in the valve cover to stop this. Reading your issue reminded me of this. Just a thought.

keithl1967

Thanks...I do have a baffle in my valve cover...I'll need to pull the plugs and take a look at them...

BlowAMouse

Just thinking out load here...

Plug check is in order...

Header coating thickness difference, maybe check temp right above the header pipe on the head itself...

If dual plane manifold, pull carb and check that the Plenum area is clean on both sides, maybe some blow back into the intake area, both sides should show the same pattern.....

Last but not least, don’t stop and drink a beer between reading the left side and the right side....

hugie82

Many things can cause this variation from cylinder to cylinder. Most of the time it's valve adjustment. If a valve is a little too tight, that cylinder will run coolers due to an inefficient burn. Next would be carb tuning. It appears you are within the normal range and pointing that lazer at the spark plugs directly on the ceramic will give you an exact, consistent temp. A half inch variation can be a 30degree difference in some spots.

keithl1967

You stated within range...what is the appropriate range for ceramic header tubes?