[panhead59]

I have a 455 with 6X heads. 1966 Tripower. Getting ready to send carbs out for restoration as car won't "keep" correct idle. Carbs need to be set up for 455 anyway. I thought this would be a good time to do the fill-in of the upper heat crossover on heads. Just "small hole" of course. I have been relying on that Fel-Pro 1233 intake gasket (which seems to work-200 miles on motor)) but might as well do the job "right" as long as there will now be some down time. Any Opinions on doing the Stove & furnace cement fill-in ? I just know it will be permanent once done, or at least very hard to remove. Any downside to doing it ? The directions call for "layering" the cement for applications thicker than 1/8". Should I layer it a little at a time or fill it up all at once ? Also, it says to heat gradually to "heat cure". Not a problem I guess if necessary. Whatta ya'll think ? Thanks in advance.

[WDCreech]

No heads have upper and lower heat crossovers. I think that you are talking about a dead hole. Filling not needed unless you are going to use a manifold gasket that doesn't cover it.

[panhead59]

OK Ok. The dead hole above the crossover. Many say the gasket is not enough. That is the main issue/question here. Obviously, Bill, you think that it is enough. Thank you. This is a street car that has to not smell like gas in the garage. I just don't want that exhaust leak and the lip from you know who!!! The cement seems like the permanent fix without checking/worrying about it in the future. Really just wondering about any bad or undesirable effects of filling it in.

[DeanBenson]

I did this on a set of 6X heads a couple months ago. In the end it worked. I haven't fired the engine yet.

You definitely have to layer it in slowly over a week or 2. I screwed up the first time. I packed the blind hole full of the stuff from Lowes that comes in a caulk tube. I had it all perfect. It didnt say or i forgot about the part of slowly heating it. I thought Ma's oven at 350 would cure it. The stuff expanded and flowed out out of the hole. Reminded me of 4th of July ash snakes that kids play with. Ma wasn't happy.

After I got all that crap out of the hole I got some premixed in a tub chimney stove cement from Ace. I layered that in a little at a time 1/8 inch or so. I used a small screwdriver as a spatula. I always tried to keep a large hole at opening so I could get the next layer in the next day. I used a propane torch to heat the cast iron then let it set overnight. It took at least a week to fill it all in. Then I baked it in the oven again at about 225.

I sanded it smooth and it looks great. I started with a file then sandpaper. I still plan to use the Felpro 1233 gaskets with my 65 tri-power intake.

Layer it slow. I learned the hard way.

[steve25]

Use Hydrualic cement to fill it!

[panhead59]

The cement I bought is " Imperial Hi-Temp Stove & Furnace Cement ". It says "resists temperatures up to 2700 F ". This is not the best stuff to use?

[steve25]

No, that will work for that useage if you have it already !