Morris Minor Owners Club

Which Mini head do I ask for at the scrapyard to ensure a straight swop for my 1098 Minor (F reg) ?

Steve

the 12G295 head from the mini cooper is a straight swap and gives a good power increase. If you find one it is unlikey to be suitable for unleaded fuel though. a later 12G940 head from an MG Metro 1275 will be unleaded, but you may have problems with the valves hitting the block.

I have a 295 head minus inlet valves and also the rarer 206 head which is complete. This was fitted to the early MG 1100. See Parts for Sale.

I suspect the Mini 1275 will be like rocking horse S**t to find, so will a standard mini 1000 head fit ?

St4eve

The 12G940 head isn't that hard to find, although not as common as other heads.
The 12G295 is a very very rare find in a scrapyard (close to impossible unless it is a mini breaker!)

Standard Mini 998 head will fit - but it has smaller inlet valves so will lose a bit of power. The head for your 1098 is the 12g202 - very common lots of them about - slightly bigger inlets than the 948 head (and the Mini head !). The 206 or 295 head is the one to go for - however unless it has been skimmed already it will need about 80 thou taken off to raise the compression ratio - this will be slightly higher than standard which is worth a bit more power and economy. The skimming won't cost a fortune and will make sure the head is nice and flat. I think wanderinstar has heads for sale at the moment. If you go for the 1275 Mini head (12g940) it is the best head around - however the exhaust valves will hit the block (some say they get away with this - I don't like 'getting away' with things. So you can either grind little pockets in the block under the valves OR sink the exhaust valves into the head by 80 thou - which is not perfect for airflow but much easier than pockets. You also must use a 1275 head gasket and re-arrange the rocker gear so the exhaust rockers act directly on the valves. Rover cheated horribly on this with the later sintered rockers - these are so wide they still hit the valves, but well off centre ! Send me you email addy and I will send you pics of the head like this i have just done. A good advantage of the 940 head is that it does NOT need skimming on a 1098 engine. So for easy fitting - 206 or 295 - they are virtually identical - only difference i know is lack of location ring grooves on the inlet ports on the 206 head.

some say they get away with this - I don't like 'getting away' with things.

The don't 'say' they state it as fact - If the seats are well sunk already (as is sometimes the case if the valves have been ground a couple of times) then the valves clear the block. Hhowever the head needs to be checked, you shouldn't just stick it on! If the valves/seats are in nominal condition then you will need to either sink the seats or pocket the block.

I have to be careful what I say in case someone comes back and blames me for their ruined engine ! (I get enough hassle on here already). I made the measurements and the exhausts really do need to be sunk quite a bit for there to be clearance . Even then - I think it is still only a very few thou that are stopping the valves banging the block - could be just a thick head gasket giving the clearance ! So my firm advice is that it WILL NOT FIT without modification to the block or the ex valve seats. I decided 80 thou sinking would give me good clearance - and still hold my compression ratio at a worthwhile figure without skimming the head. BTW - a 206 or 295 is NOT a straight fit on a 1098 engine - the combustion chambers are bigger and so the compression ratio will be down. So these heads DO need skimming before they are worth fitting.

This may seem daft, but how do I tell which head I am looking at ie 12G940, 12G295, 12G206 etc. ?

Steve

It's cast into (onto) the head, just under the rockers.

Casting number on the top surface - under the rocker cover. Seriously - get in touch with Wanderinstar and grab his 206 head from - they are hard to find in good order these days. Check if it has already been skimmed - heads were all 2.75" thick when new - and if not get it your local machine shop and have 80 thou off the face. De-burr the edges, grind in the valves - and you will have a useful improvement in performance.