47 head & 51 engine block - amazing mismatch

[Robin (UK)]

Guys,

Today, ordered a cylinder head gasket and was asked whether or not I needed the early, or late style water porting.

I checked, and discovered that my car, which runs a D42 motor, is fitted with the earlier cylinder head.

I read a thread recently, regarding that extra water port at the front of the engine and I was amazed to see that, in my car, the block has the water port and the head doesn't.

I've had the car three years and not noticed.

I've also run it for thousands of miles - no problems.

My guess is that someone must have capped that port on the block.

I'll find out for sure when the head comes off.

It's crazy, the stuff you can find on old cars!!

[BobT-47P15]

Guess I should sometime check on mine. Has a '57 model Plymouth motor with a '50 Dodge head. No apparent problems with overheating.

[james curl]

The hole in the front of the block is covered by the water pump. If you have the old style cast iron thermostat housing and the by pass elbow then the hole should be blocked by the water pump gasket. If you have the straight steel thermostat housing and no provision for a bypass then you need the head with the bulge over the hole for the water to by pass the thermostat and the hole behind the water pump needs to be open. If you have the later block and the earlier head I guess you could run it without the by pass with the water pump gasket covering the hole that goes to the top of the block.