While my engine is out of the car, I've taken the opportunity to address my exhaust problems. You may recall from my previous reports on the car that my rear exhaust manifold is cracked. It seems to be home-made, and I don't think that it was made quite right. When the cross-over pipe is attached and tightened, it seems to put stress on the manifold, which, I think, caused the cracks. I welded the cracks (again), but I'm afraid that the stress could cause more cracks. So I found another manifold on Ebay. The picture below shows my manifold with the one I bought.
Rather than doing any cutting or welding on the "new" manifold, I just plugged the O2 sensor hole, and made a plate to cover the outlet. (My O2 sensor is on the other side of the engine.) I cleaned the manifold and sprayed it with high temp silicone exhaust coating.
I also cleaned and coated the front manifold, which, by the way, is cast, and not cracked. And just in case I have to use it, I cleaned and coated the old rear manifold.
The instructions on the can of exhaust coating say to bake the sprayed parts at at least 400 degrees to cure it. So I set my oven to 425 and put the pieces in. And, of course, my smoke alarms went off after a while, so I had to open some windows and clear the air. But at least, the parts are coated and cured now.
You may recall in my earlier report that I had found the rear manifold to have been installed with no gasket. Well, the front one also had no gasket, and i think it was leaking slightly. Thay may explain why the vacuum line to the transmission modulator kept melting. I'll use a gasket when I put it back on.
