Crossflow heads

[RobStan]

Morning all

I've still not made a final choice about my engine rebuild. Can someone tell me what the difference is between the GT and the Mexico head?

Cheers in advance.
Rob

[Monkeythree]

No difference. They're one and the same thing.

[pumpkin]

There are two different heights of X-flow blocks and heads. When I put a short block with a short head on my Seven in the 70's the head gasket kept leaking until the head of one of the valves fell off! All the valves were touching all the pistons. In the end the engine with cut outs for the valves in the top of the pistons was really good, presumably with a significantly higher compression than normal. It happened because I exchanged the head and the block at different times for Ian Walker Racing parts. They did the machining of the pistons and other repair work to make up for their error.
I don't know whether this is relevent to your question or not but it is a good story!

[RobStan]

Cheers for the head info and the story. I was looking at getting the head and block done at the same time so it should be a problem, but I'll check the heights anyway.

What do we think of the Piper cam, bp285?

[heightswitch]

RobStan said:

Cheers for the head info and the story. I was looking at getting the head and block done at the same time so it should be a problem, but I'll check the heights anyway.

What do we think of the Piper cam, bp285?

The 1600 711M block and earlier GT block all have the same block height.

the 1300 711m block and 1100 Block are all approx 1" shorter

hence all bores roughly the same with strokes and blocks to make capacity. This is why you can fit 1300 pistons into a 1600 block, machine the piston crown for valve pockets and run higher compression.

N.