Morris Minor Owners Club

Just checked the oil on my daughter's minor and there is a white emulsion in neck to filler cap. I first noticed this at the weekend and cleaned the filler cap area but it has come back since then.
So that usually means head gasket to me.
Whilst it is off I would ideally like to change to unleaded head BUT in the near future I want to replace the 1098 with a 1275 and dont want to waste money on a 1098 unleaded head.
Question. Do any of the Minor parts suppliers do a 1275 unleaded head, I can give them an exchange 1275 head from the engine I intend to put in but then would that 1275 head work on the 1098 engine until I have time and money to change over engines.
Or should I just throw another head gasket on the 1098 and keep putting in additives till I get round to the change over later?
Problems, problems
Dave

The white emulsion is quite common and may not be the head gasket.
Is there water in the oil or oil in the water? Has there been loss of power?
If not the problem may just be condensation due to mostly short journies where the engine doesn't get hot enough.

Do some engine oils have a greater tendency to emulsify than others?
The problem has started since I changed oil / filter and put in GTX and a canister type filter. Could be coincidence but with the old filter and oil it was never there.
My daughter is normally doing about 60 miles a day in the car so it shouldnt be down to short journeys however since I cleaned out the filler cap last weekend up to today the car has hardly been used and has been in the garage and yet the emulsion had grown in the filler cap neck.
No sign of oil in the radiator.
Dave

Dave,

Just a thought, did you clean out the breather pipe to the air filter?

My engine (reconditioned) produces some emulsion at first, so I cleaned it all out, then remembered the tube from the rocker cover to the air filter - cleaning that out helps to keep the vapours moving!

Colin

Thanks Colin
I'll give that a try.
(If anyone notices that I was asking you to identify a "late" breather filter yesterday that was off a different Minor )
Dave

As Vernon says, this is quite common on the Minor and does not always
indicate head gasket trouble. It was once a theory that the air hitting the
front of the rocker cover was not hot enough to prevent the emulsion forming
and it went as far as to suggest making a shield which diverted the air away
from the rocker cover. I tried it and it made no difference! I had two Minors
at the same time, both used equally, and one always produced emulsion, the
other never did.

The engine is possibly running too cold - fit an 88 degree thermostat which will improve the heater no end - and probably chase away the emulsion. But engine breathing is very important too - so clear the vent pipes, and check inside the rocker cover - sometimes the breather on the top gets blocked with gunge where it leaves the rocker cover. Don't rush to change the head gasket - probably nothing wrong with it if there are no other symptoms - and while the 1275 head 'can' be fitted - it needs little 'pockets' let into the block to allow the ex valves to go down ! If you really want an unleaded head for your 1275 - just get one from ebay for less than £50. But it's quite safe to run the leaded head on unleaded fuel - nothing desperate is going to happen - if eventually the ex valves settle in to the head slightly then that's the time to have inserts fitted - but it may last 5 or more years, especially if it's being driven gently!!

Cleaned out the breather pipe to air filter, there was quite a bit of gunge in the vent pipe to rocker cover and also in the entrance to filter pan where there is a small hole at the entrance. I will keep an eye on developments for next few days, I have a head set so if all else fails it is a job to get me away from tv on Boxing Day!!
Dave

I have a head set so if all else fails it is a job to get me away from tv on Boxing Day!!

That really would be a case of wasting your time & money fixing something that isn't broke! This is my 7th Winter and every year I've had the mayo yet I've never had any head gasket problem. Believe me, you will know if the head gasket has gone because the car will barely go. The Minor tends to run cool due to the over large radiator and this is simply a consequence of that. Just clean the mayo out of the cap every now and then.

Get the engine temperature up! I forgot about the daft wee hole - i drill this out to 3/8" to improve the draft.

I have had this a lot over the years and its a characteristic of Castrol GTX I get it much less with other oils.

It doesn't seem to to do any harm and high speed runs with higher temperatures eliminate it.

I'd just clean it out now and again and otherwise not bother

Dave,

Don't get too enthusiastic drilling out the vent into the air filter base!

One Moggie I was driving hat an enormous hole in the vent, this resulted in a blocked air filter and coasting to a halt on the M4 hard shoulder. Then I had oil dripping out of the air-filter intake!

The suction through the full bore hole was so ggod that it was sucking oil from the rocker cover into the air filter (and it was a paper air filter - not an oil bath - well it was to start with).

Colin

Thanks everyone for your comments. I've learned the following:-
If it aint broke dont fix it
Next oil change dont use Castrol GTX
Leave hole in air filter as is but keep clean
Ordered 92 deg thermostat last night
buy plenty salad to use up mayo production
Thanks
Dave

Under no circumstances drill out the small hole in the air filter inlet tube.
If you do you will definitely have oil dripping from the bottom of the casing.
Leave it as designed.

But it don't half keep the fumes down on the engine - and no leaks. Yes - if the engine is well knackered then mucho fumes will be drawn through and the filter will get oil on it - never had it dripping out though! In fact I rememeber now that I also re-directed the pipe to come up inside the paper oil filter - and this solves all the problems.

The engine does not have to be in bad condition to give oil dripping from the
air filter if the original hole is opened out. This problem was aired some time
ago when it was found to be the cause of the excess of oil in a members car.
The hole should be approx 1/8" bore and should not be opened out. The size
was not picked at random by the designers and is perfectly satisfactory.

Maybe ok for new engine ! I found it much better - just passing on my experience. Take it, or leave it.

I also wrap a piece of cooking tinfoil around the thermostat housing and the front end of the rocker cover to warm the latter up a bit. Got to make sure the foil doesn't touch the front sparking plug or the fan, but its easy enough.
Incidently, I see you all call the gunge mayonaisse. In our house its called meringue after the wife's efforts which are much the same colour and consistency. Her's taste better of course, and the kids have grown up thinking that's what they should be like. And they called them meringoos. MikeN.