The Stovebolt Site Forums The Shop Area Engine Shop Splitting the manifolds

Anybody heard of splitting the exhaust manifolds on a 235? If so how to do it?

I've seen it done. Basically, you cut the manifold into 2 parts, with one side keeping the heat riser (most I've seen keep the riser on the rear part). You would then weld a plate over the open ends to seal them, and on the part that doesn't have a exhaust pipe flange, you would cut an opening and add one. I've seen nicely done ones, you would almost swaer they were factory made, but most I've seen were rather sloppy.

Mine was pretty sloppy. I just blew a hole with a torch about 3 inches back of the front of the exhaust and welded a flange on it and hooked on a flex pipe. Probably a 1st class job for a 16 year old and it sounded GREAT! However it was a 216 in my 51, 210.

There are split exhaust manifolds for the 235s on ebay almost all of the time. As Longbox55 says, some are "rather sloppy."

Back in 1955, I bought a split manifold kit from Almquist for the 235 in my '53. The kit consisted of a short manifold for the aft three cylinders with an exhaust pipe flange, and hardware and instructions for modifying the original manifold to accept the new aft manifold. What I had to do was to cut-off the aft portion of the original manifold just aft of the heat riser and stock exhaust pipe flange, using a hand hacksaw. Instead of welding a plate over the hole now in the stock manifold, Almquist provided a plate, gasket, and jack-bolt that sealed the hole without welding. Has anyone else seen this type of split manifold? The one that i had is the only one that I have ever seen.

This system worked perfectly. However, I replaced it in 1957 when I heard about the Corvette six dual exhaust manifold. The Almquist split manifold kit cost about $30, and the new Corvette six manifold from the local Chevy dealer cost about $13. I would not be surprised if the Corvette six manifold might go for a little more than that now.

Very very few people are is interested in that. I would know.


https://www.stovebolt.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=460280#Post460280

Hey Curt,

I didn't see your offer for the split kit as I don't read the swap meet area very often. You might want to post it here to see if you get more results. Count me in if you can get enough participants. Your outlet flange is the nicest fitting I've ever seen. Finding a local welder shouldn't too much of a problem.

-Ed

I think Curt's split manifold is one of the nicest I have seen. So much so that I have collected the parts to make my own. The shop where I work plasma cut a flange and I got an elbow from McMasterCarr and a manifold off ebay for 10 bucks. I am ready to go, when I can find the time.

This is how I did it on a 302 GMC

http://oldgmctrucks.infopop.cc/eve/forums/a/tpc/f/633004236/m/7851087782?r=7851087782#7851087782