The Stovebolt Site Forums The Shop Area Engine Shop 216 manifold

Hi guys,

I recently replaced the exhaust on my 1940 1/2 ton and noticed a manifold leak at the gasket. Took off the manifold,thinking it was a bad gasket, but on closer inspection noticed that the exhaust ports on the manifold were actually a little shorter than the others. I had another manifold laying around from another donor engine and checked it out--a bit better, but still when placing the manifold on a flat surface those ports are a little off the surface. I did a quick fix by doubling the gasket there, but there is still a very small leak. Question: is this normal wear and can the manifold be milled to fit tighter? Recommendations will be appreciated.

Thanks,
Jim

In short, yes. I do this often for engines ranging from Model A's to Studebaker flathead 6's to even aluminum marine exhaust manifolds. The cast intake and exhaust manifolds become distorted from all the heating and cooling cycles over the years and no longer form a single flat surface when bolted together. Disassemble them if you can, clean all the rust and crud off them, bolt them back together as best you can, and then have the gasket surface milled as a unit. Will be perfect then. Some shops also use what amounts to a large beltsander to surface these. Either way. Try NAPA in Northfield there, they do alot of tractor work and should be able to help.

Barry's right. One thing that I try before machining is to put a bead of ultra-copper RTV between the manifolds and the gasket to the head. Bolt on and tighten, then let set for 24 hours allowing the RTV to cure. In most cases this fix works, I've gotten to where I don't put a manifold set on the inline six without it.