Club Cobra - Stumped!

Quote:

Originally Posted by jhv48 (Post 1197435)

I'm having trouble wrapping my mind around this one.

So, engine rebuilt, total .60 overbore. Engine overheats but water is flowing correctly, thermostat is functioning fan is turning on at appropriate temp, radiator is shrouded. Now, the right bank plugs are white (doesn't necessarily mean a lean condition. Could be getting steam cleaned by water leaking into the cylinders), while the left bank show rich conditions. Dual plane intake should equalize, somewhat, the fuel distribution to both sides of the engine, thus ruling out the carburetor and you have eliminated a vacuum leak. Timing would effect both banks as well. Since the temps appear to be higher on the right side, I would borrow a laser temp thermometer and see how the right side header temps compare to the left side before I did anything else. My guess is that they're about equal. If the right side is significantly higher, then I agree, the head is coming off. Something is causing that side to reach higher operating temps. Either a water jacket is blocked by debris or a gasket moved during installation.

If you were losing any water, then I would suspect a head gasket leak, as the plugs could be getting steam cleaned by the water in the cylinders. That's why they still appear brand new.

My bet: intake or head gasket leaking on the passenger side. My first choice would be head gasket.

In many cases, you won't see actual water or clean plugs if the head gasket is leaking. It has to be leaking pretty bad for that to happen. What you see is exhaust gasses being pushed into the cooling system in small amounts thus superheating the cooling system beyond what it can cool. This was real common in certain smaller 4 cylinder cars like Escorts. As I mentioned in a previous post, we used the "bear bottle method" as it was 99% accurate. The high pressure exhaust gas would continuously pump into the cooling system and you would see a constant stream of bubbles from the overflow.