Inliners International Forums General Discussion Tech Tips Offy intake manifold with water heat

I found out that if you use hot water heat with an Offenhauser 2x1 or 3x1 on 216, 235 or the 261 Chevy, that you need to pull out the two small metal plugs from the bottom of the Offenhauser intake manifold and weld an aluminum slug it their place. The Offy pressed in metal plugs are not water tight and they will end up dripping water.
I don't know if the later 250/292 intakes have these plugs or not, but if they do they will also leak.
The aluminum slugs that I used were .125" thick by .850" diameter and fit real well after I had drilled a 3/8" diameter hole in the Offenhauser stock metal plugs and pried them out with a screwdriver.
If anyboby needs a couple of aluminum slugs to weld in, contact me as I have a few extras at no charge.

Ed,
I have been trying to heat my Offy on a 230 for a month now. Each time it ran for about 5 minutes and then leaked like a sieve! I kept working with different gasket material hoping to cure. When I took the manifold off last night, I found two plugs with little holes in them on the bottom. Is that what you're talking about? If it is, I sure could use some plugs! I'd be glad to pay for them.

Thanks,
Bob Dale
631 Forest Park Drive
Newburgh, IN 47630

I now have some pictures of how I removed the steel plugs from the Offenhauser 2x1 and 3x1 intake manifolds for 216, 235 and 261 intakes. I don't know how to post pictures here on the forum, but I would be glad to send the pictures to anybody who request them. I also still have some free aluminum slugs that can be welded in to stop any leaking for those who run their intakes with hot water heat and wish to weld them in.

I have just one that just a single 4bbl put water on it and it has not leaked yet..