Morris Minor Owners Club

hi, i have had the car for 4 months, bought it and drove it from leeds, engine was spot on (1965 4 door 1098 )but now, even though the car pulls great and no smoke when driving there is a lot of mayo in the rocker cover cap, losing water in radiator and oil is also going down, i have the paper air filter, and when i take the rocker cap off there is fumes coming out, dont know if i need a new head gasket or if its something more serious or just a good service needed also when i come to a junction and take it out of gear the engine ticks over more than it should, if i use my foot and push up on the accelerator pedal it goes back to normal tick over had a look at the spring seems okay. cheers

When you take the cap off and rev up the hot engine - just how much fume comes out of the rocker cover ? A gentle stream - or a cloud of fug ?? I suggest you take the cover off (may as well check/set valve gaps while in there) and clean out all the mayo - and make sure the breather connection is clear - and the pipe running to the aircleaner. But it is MUCH better to connect that pipe to the brass tube on the side of a later HS2 carb. This is far better at removing the fumes (and burning them) - and should help. Also saves the filter getting plastered with oily sludge! May be an idea to do an oil and filter change too - and fit a higher setting (88C) thermostat so the engine runs hotter in winter - all helps to keep the mayo under control. The sticking throttle suggest a new throttle cable may be a good idea - get a nice long one with a nice gentle sweep from bulkhead to carb.

losing water in radiator and oil is also going down

This strongly suggests the head gasket needs replacing, while you have the head off you can check the condition of the bores.

With regards to the mayo... it can depend what sort of running you are doing. Short hops of a few miles or only occasional use in this kind of weather can lead to a build up as the engine does not dry out enough.

My main experiences with head gaskets going is where the compression sealing rings go allowing hot combustion gasses to escape which is VERY noticable

The oil goes down in most Minors......and the water should not be filled right to the top of the rad - let it stabilise a couple of inches below the top, but above the fins of course.

thanks to you all for the advice, when i rev the engine up there is not a great deal of fumes ,like you say probably needs a good service and will try and buy a carb with the brass end on will also buy a new throttle cable, have had the rocker cover off and cleaned out all the mayo, the airline from the rocker to the filter was just about blogged up never adjusted the tappets but will do when i service the car, thanks again for the advice

The cleaned out breather pipe can only help!

hi, i think i need a new head gasket can see water bubble out between the block and head, checked plugs 3 spot on 1 a little bit black. cheers

Hi.
Sorry to hijack your thread, I just wanted to get back to what bmcecosse said earlier in the post. My 1098 has the breather going from the rocker cover to the airfilter housing, it also has a pipe coming off the top of the float chamber on the carb which just has a long rubber pipe venting nr the bottom of the engine bay. Would I be better off connecting the vent from the top of the float chamber to the rocker cover? And if so would I just leave the unused stub on the airfilter housing open?
Thanks.
Neil.

What carb do you have? As far as I know there isn't a vent from the top of the float chamber that a pipe could be attached to.
The only pipe there (on a standard carb) is for petrol to go in.

I don't think that's the right pipe to connect the breather pipe to. It sounds to me more like a fuel vapour vent off the float bowl. If the engine breather pipe connects anywhere it must be to where the fumes will be sucked directly into the inlet manifold so they will burn with the air-fuel mixture in the combustion chamber. Venting from the valve cover to the air cleaner was considered good enough at one time but it does tend to soak the paper element with oil causing restricted air flow to the engine. Venting a little way down-stream from that saves the paper element and also creates a low pressure in the crankcase that will help reduce oil leaks elsewhere. Some late models, like my 1967, had a Breather Control Valve (PCV in North America) that connected to a side cover. (Page AAA 10 in the Shop Manual)

Any such device must have a restrictor to limit the amount of air being admitted after the carburetor or the engine will run much too lean.

Sorry about the "lesson in engine design" it's what I did before I retired

Darrell McDonald

To be safe I'll leave the rocker cover breathing into the airfilter and the float chamber top breathing into fresh air then

It's very much better to have the rocker pipe going into the connection on the side of the later carb - but DO NOT connect the float bowl overflow to anything except fresh air!

when at idle i was getting a high tick over, tried a new throttle cable ajusted the tick over screw still no difference, then noticed that the accelerator pedel was not as high as it should be ,wedged the pedal up pulled the slack through and now the tick over is spot on

Can't see how that would affect tick-over ?? BUT - what you must check now is - when the carb is at full throttle - is the pedal on the floor ? If not - if there is a gap under the pedal - then you will snap the throttle cable in time......

cheers bmcecosse will check that tomorrow

the tickover went back to high idle, have been tring to sort this out for 2-3 weeks, back out again today after renewing the head gasket yesterday , it runs great much better than before but still could not get the car to idle properly ,so having a good look around the carb area and noticed that the spring was not pulling the throttle far enough back to the closed position (brand new spring) then had a good look at the bracket on the exhaust to manifold bolt, it seems that who ever put the exhaust on fixed the bracket to the insde nut nearest the engine instead of the out side nut, so changed it over now sticks out further and gives a good pull on the throttle now tickover is how it should be, it just goes to shown a simple thing like that can have you running round in circles ,thanks to all who tried to help me find the cause. cheers

Don't have the spring set any tighter than necessary - the car is much nicer to drive with a 'light' throttle - and the heavy spring will wear the throttle cable - and the carb spindle bearings!!

I have renewed the head gasket, found a little v shaped grove in one of the exhaust values, ground in a new exhaust and inlet value tightened down head then again after a run, can hardly hear the engine at tick over much better, no fumes coming out of rocker oil filler now need to renew timing chain as the engine is that quiet i can hear it rattle. checked the bores while the head was off smooth as a babys bum, thanks all