coolant path through heads...blocking off rear two paths

[Will Reeve]

Just installed a offenhauser inlet manifold. The rear two water ways are blanked off; why is this and does it cause the rear cylinders to get hot?

[Blown v8]

Used offy's for years,never had any trouble with the rear cylinders over heating !

[ChrisJC]

Not a problem. All the inlet manifolds are like this.
The reason is the heads, not the manifolds.
The water runs from the water pump backwards through the block. Then it rises at the back into the heads and runs forwards. At the front of the heads it exits into the inlet manifold and to the thermostat where it either runs to the rad, or bypasses the stat back into the pump.

So there is no need on the heads for the water ports at the back. However, the heads are both the same, so to get the symmetry, you have to put a port at both ends. And then block it off with the manifold!

Chris.