Thread: Wanted: Advice on Filling Exhaust Crossover

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Question for group.

I want to completely fill in the heat crossover passage in some old cast iron stock intake manifolds. Is there a ceramic slurry, or mix that can be poured in to accomplish this?

Thanks ahead of time.
Jeff

I'm wondering why?

Usually using the stainless steel block off plates works well. The big advantage is they can be removed. My own experience on street engines with crossover block off is they are a royal pain to drive in cool/cold weather because the car becomes very cold blooded.

If it's an early style manifold where the crossover actually runs inder the front of the carb and seals with the carb gasket, (which can really erode the base of an alluminum carb) I usually drill and tap the holes in the intake under the carb for pipe plugs to close them off.

Just because, that's why
I've done the blockoff plate thing and even machined 3/16 plates to put in there.
Not a winter problem here in Florida.
I am just looking for a compound to use.
Jeff

Originally posted by Mike P
I'm wondering why?

Usually using the stainless steel block off plates works well. The big advantage is they can be removed. My own experience on street engines with crossover block off is they are a royal pain to drive in cool/cold weather because the car becomes very cold blooded.

If it's an early style manifold where the crossover actually runs inder the front of the carb and seals with the carb gasket, (which can really erode the base of an alluminum carb) I usually drill and tap the holes in the intake under the carb for pipe plugs to close them off.

I have seen the heads plugged with lead before. It was on a odd race motor and they didnt have any other options. they had to use stock heads.

I've used a piece of a stainless butter knife to block the crossover on a Ford FE intake. You can use a die grinder to bevel the intake to fit the plate flush snugly. Then some hi-temp sealer to hold it in place till intake is installed. Some will just use sealer and not seat the plate but I like it to sit flush. Also heard of drilling a small hole in the plate to release any buildup of heat but have never tried that one myself. BTW the butter knife trick is really old school. LOL, G.

i guess you could use block filling compound like people use for filling water jackets on drag race motors