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MG MGB Technical - head casting interchangeability

Hi All,
I bought a cyclinder head thinking it was for an MGB. The casting number is 12H1670 which turns out to be for a 1622cc MGA engine(I think). The head is for modifing for fast road use for a 1860cc with unleaded seats and bigger valves.
Will this casting fit on the block or do I need to find yet another casting. The 1st casting was cracked around number 3 plug up to rocker cover gasket face.
Many thanks for any help.
s page

Hi Simon

I don't know if it is compatible with an 1800. If it turns out that it is, you will need to check that the rocker oil feed lines up OK, as some 1800s had an offset oil feed.

Just changing from one 1800 head to another can cause an issue if you don't have the appropriate rockers.

I'm sure Peter Burgess (and others) will be able to advise on suitability for the application.
Dave O'Neill 2

Hi Dave.
Many thanks for your imfo.
Simon
s page

The valves are smaller. Was your old head an early or late one? The early head uses a 43 cc combustion chamber, while the later one uses a 38 cc chamber. You need to match the pistons to the head or you'll gave too much or too little compression. RAY
rjm RAY

Other incompatibility issues aside, if the oil feed to the rear pedestal is offset you can get a pedestal with the appropriate offset. A pal has just had to go through that process when replacing a cracked head.
paulh4

Simon
If you are correct and the casting is for a 1622cc MGA it may be worth more to the MGA owner than the head you need for a 1798cc B. NTG would probably want it but as Dave suggested, Peter Burgess will advise on suitability,
Roger
Roger Walker

1670 casting not extra valuable it is seen more on the Morris Oxford/ Austin Cambridge 1622, the 432 1622 is the rarey one. With 1.56 inlet and 1.343 ex it would be ok as an Econotune spec head with a min skim it should be around 38cc. For Fast Road I think I would prefer an 1800 casting as a starting point.
Peter
Peter Burgess Tuning

This thread was discussed between 29/12/2016 and 01/01/2017

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