Thread: Olds 455 intake sealing question.

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Ever since we got my Son Dan's rpu running we have had a slight issue with the two front plugs on the drivers side (#1 and # 3) getting oil fouled. It runs fine, but it has been getting progressively worse. The fix was easy, we just kept clean plugs and would swap those two out every so often and the car would run fine again. We kept thinking it was the rings not seating yet and that it would stop eventually.

I took compression readings and all were exactly the same at about 210 lbs each, and a leakdown test showed only about 10% in each cylinder, so all seems well there. We replaced the valve seals on those two intake valves, but the old ones looked great and it made no difference.

Spoke to a very helpful tech guy at Mondellos the other day and he said he sees this all the time. Asked if we were using that large tin valley pan gasket and I told him we were. He said that one doesn't work well with the Olds W30 tripower intake and that what was happening is that oil is being sucked into the intake port of the head out of the lifter valley. Makes total sense. I ordered a composite gasket set from him and it came in yesterday.

When we pulled the intake off there was evidence of oil being sucked in, as he had said. The intake ports on those two were oily and sooty and very little rtv sealant was on those ports. Got everything cleaned up, installed the composite gaskets (which he told us to seal all over with rtv silicone) and torqued down the intake. But I noticed the rubber front seal that goes across the block seemed not squashed down like it should and I was able to put a feeler gauge between it and the intake.

We pulled everything back off, and are going to have to order a new set of gaskets tomorrow as they got destroyed taking them off. Here is my question. On some Olds forums I have read that people toss those rubber end seals and use rtv instead. Is that what some of you who build engines would do?

Don