Clifford's original and early style manifolds did not have provisions for exhaust or water heat. I have an early 230-292 2 x 4 no provisions. What they did sell was a carb base plate that they called "thermo" something or other. I will have to dig out one of my old catalogs. Ran hot water through the spacer to provide heat, something akin to how Edmunds did it with their manifolds (copper tube cast into the manifold for hot water in and out. Clifford did it via spacer). Some later original era manifolds may have had a small chamber under the manifold cast in, no holes drilled or tapped, you made a plate.
Clifford changed its castings at some recent point (and may have done so with input by Tom Langdon). So my new style Clifford 235/261 2 X 2 has a hot water chamber built into the casting so no need to use the spacer plates. There is no provision on that manifold for a plate for exhaust heat. Other new style Clifford manifolds for other motors may have both, I have no knowledge of that myself.
Other manifolds of the era were cast so that they could be bolted to the stock exhaust manifold. Fenton, Weiand, Offy are examples. Others did not have any provisions. for those with the exhaust heat chamber, you could make a plate up and bolt it to the bottom of the manifold to cover the exhaust chamber and run copper lines from the exhaust manifolds if they had a provision for that, or run hot water. On my Weiand set up, I ran hot water. It always eventually had a small leak but it worked way better then the exhaust tubes.
One caution here, a lot of the vintage manifolds had a large core hole or two on the bottom, presumably to get the sand out after the casting, like one or two holes about an inch wide or so. After the sand was vibrated out, steel core plugs were staked in place. A good example is the offy intakes. These core plugs worked fine to keep exhaust gas in the chamber, but are prone to leaking when water is plumbed into the chamber so you have to weld aluminum plugs over them to keep it from leaking. So if you have a manifold like this, and are welding the core plugs shut, you might just weld a plate for the exhaust chamber (for the stock exhaust manifold) an eliminate the potential for a leak at that spot (which I always had, a little leak, constantly taking it apart and new gasket and silicone sealer).
Last edited by mdonohue05; 02/21/18 06:15 PM.
