Exhaust Manifold outlet port

Mon Oct 14, 2013 5:18 pm

Does anyone know if there are different sizes of the exhaust port, that is the hole that the exhaust pipe elbow screws in to? I bought a new manifold and it looks like the port is larger than my old one.

thanks,

The Riot

Re: Exhaust Manifold outlet port

Mon Oct 14, 2013 5:26 pm

the late model cubs used a larger fitting than the early ones, sounds like that is what you bought,to use it you will have to get a pipe bushing to make it fit the early pipe
Tim

Re: Exhaust Manifold outlet port

Tue Oct 15, 2013 7:05 am

Thanks, Tim. So using a reducer to go to the smaller pipe won't hurt the engine due to the restricted exhaust?

The Riot

Re: Exhaust Manifold outlet port

Tue Oct 15, 2013 7:50 am

no issues

Re: Exhaust Manifold outlet port

Tue Oct 15, 2013 8:19 am

I also have seen aftermarket exhaust manifolds with the larger outlet port. They actually came with the screw in bushing to adapt your original size exhaust pipe.

Jerry

Re: Exhaust Manifold outlet port

Tue Oct 15, 2013 8:27 am

In addition, the original is 1 inch pip thread, and the larger is 1 1/4 inch pipe thread. If you elect to use the 1 1/4 without reducing, they frequently have a clearance problem, also IH mufflers do not fit, but there is an AC muffler that will, though it looks different. Unless you have done all the other things to try increasing your horse power the reducer bushing is the way to go.