Morris Minor Owners Club

Can anyone tell me please what the casting numbers CAM 4810 on a cylinder head purporting to fit a 948cc engine means. It has the later solid rockers. It has a 9 hole stud pattern, heater take off and temperature sensor orifice. It also has the by pass hose spigot. What engine will it be from.

That number refers to an A+ head, probably from a mini.

Thanks MT any problems fitting it to my 948cc minor, the valves are the same size.

No problems at all as far as I know. The only changes I am aware of on the A+ heads, was the fitting of proper type valve stem oil seals. Top hat type, with a spring around them. BMC eccosse is the cylinder head expert though, and may know of a few other changes.

Yes it has that type of valve stem oil seal.

It will fit perfectly well, the valve sizes may be the same but the porting is much worse and you will lose power. You would do better to fit a 1098 head with the slightly bigger valves and better porting

that's a shame Matt, its unleaded, and I got it cheap, is there anything I can do to imrove the porting.

Not a lot... if the unleadedness is important too you put it on and see how it performs.

I have put a CAM4810 down a refuse chute on the 9th floor (it made a nice noise when it hit the bottom) because its a poor head

Right Matt, whilst I am on a roll (in rubbish) I have another head a 12G 202 is this one any good?

Yes - it's the same as an original 948 head, no better or worse porting wise, but not as good as a 12G202 head - or a 12G295 - or a 12G940 in order of 'betterness'! As Matt says - if you want unleaded and not bothered about extra power - then it will be fine on a 948. Used on a 1098 there will be some power drop. I too have given these away - sadly no big drop to play with!

Oh bu@@er, the 12g202 isn't unleaded, I know I am flogging a dead horse, but how much power loss will the cam 4810 cause, I am only a fair weather driver, the furthest I will go will be to the National Rally in Leicester, I am just fed up of faffing about with additives. I am considering marrying a 1098cc box as well, will this make the situation worse. Lastly there is a company local to me who does unleaded mini heads at a good price, apart from the ones Matt mentioned which other ones would be suitable? Thanks for your advice, I am slowly working back through all the mechanical posts, fascinating stuff, a bit repetitive, including me.

If the engine is 948 there will be NO power loss. If it's 1098 then there will be slight power loss -but not significant if you are just trundling along. The 202 is a better flowing head - but needs skimming (60 thou) to use it on a 948 engine. Don't bother with 'additives' -really not necessary unless doing v high mileages and driving the car hard. I've never used any in 7 years - I don't do high miles but I do drive the car hard - and never had any problems. Worst that can happen is the exhaust valve gaps close up - so set them at 15 thou -and keep an eye on them, maybe every 3000 miles.

thank you, at least I have a couple of heads if the worst happens, 3000 miles about 5 years motoring for me. an annual check can be done at oil change time.

You DEFINITELY don't need additives!

as I said in a previous post, I am reading previous posts in the mechanical section. I have found one recommending changing a 948cc camshaft for a 1098cc one. I am taking my engine out, when its a bit warmer, and I have a spare camshaft. I was thinking of changing the oil pump. is it worth changing to the 1098cc camshaft as well, Your thoughts please.

Yes it is a better camshaft with extended valve period and higher lift. So if you have it and the engine is coming out anyway (although the cam CAN be changed in-situ ) then make the swap - especially if you also fit the 202 head after skimming it 60 thou - you will potentially have the same power as a 1098 engine (48 bhp) but of course at slightly higher revs.

Should have listened, I fitted CAM 4810 head to my rebuilt 1098 engine, the performance is worse than my standard 948. I am going to fit 12g202 head and forget about unleaded conversions.

Wise move - but a 12g295 will be better, a 12g940 much better! Don't worry about the 'unleaded' caper - it's much overplayed.

been trolling ebay and auto jumbles for either of those heads,nothing has come up yet.

The 948 camshaft is utterly miserable accorinding to BMC, I have an MG Metro cam fitted on my 948 as per BMC's recommendations. Give me a year and ill tell you how it performs!