12G295 Head

Post by **hamford14** » Thu Oct 01, 2009 3:24 am

Hi,
I am thinking of fitting a 12G295 head to a 948cc motor and was wondering if that is a straight fit or not? I thought I heard that the head had to be skimmed but I'm not sure.

Any help would be much appreciated,
Thanks Todd

Post by **Peetee** » Thu Oct 01, 2009 7:52 am

Yes it is a straight fit and yes it does need skimming to bring the compression back to comparable. I had 60thou taken off mine and it went like a train! It makes for a very nice engine. My 1275 might be faster but it's no where near as smooth.

Post by **bmcecosse** » Thu Oct 01, 2009 10:44 am

I would say 80 thou will make the compression nearer the mark. But to get best benefit you will also need a larger carb - and look for the MG Metro alloy inlet manifold - that's where the greatest power gain lies !

Post by **Peetee** » Thu Oct 01, 2009 4:15 pm

As ever, check it hasn't been skimmed already. Memory fails me but someone will come along and tell you the depth of the block so you can check.

Post by **bmcecosse** » Thu Oct 01, 2009 6:39 pm

All heads (not block!) start out at 3.750" thick. Anything less means it has been skimmed - and by how much.

Post by **les** » Thu Oct 01, 2009 10:09 pm

I think that should be 2.750'' thick!

Post by **bmcecosse** » Thu Oct 01, 2009 10:10 pm

Sorry - yes -2.750 " slip of the mind!

Post by **Peetee** » Thu Oct 01, 2009 11:58 pm

With a 1" skim you could probably run it on diesel.

Post by **hamford14** » Fri Oct 02, 2009 3:09 am

Just checked and it hasn't been skimmed,
Thanks for the help,
Todd

Post by **bmcecosse** » Fri Oct 02, 2009 3:07 pm

Good! Have 80 thou off it - and be sure to take the sharp edges off the rim of the combustion chambers - see another thread where the car has 'running on' problems.