Morris Minor Owners Club

Hello everyone,
I have just completed a restoration on my moggy and have spent a small fortune on the mechanics and just when i thought
everything was running well i have been having problems when starting from cold. After a mile or so the exhaust blows out
clouds of blue smoke really thick,then after two or three minutes it will clear! The trouble is it's burning oil and chucking it
out of the exhaust as the tailpipe is wet with oil!
I have since taken the head off and had it checked by the engineer that did the work on it for me. It has had new guides and stem seals and quite a bit of port work done and as far as he can see it all looks fine. Can anyone think of anything else that could cause this to happen? as i'm a bit stumped!
Thanks
Andy

You have to run it in which means taking things easy for the first 500 miles (no labouring in any gear, no revving or hard driving) and changing the oil after 500 miles.

Is it actually using any oil (based on the dipstick)?

I cannot give you any more advice as I have never had a rebuilt engine, but it might be worth mentioning that on a Morris Six I went to see, which claimed to have had its engine rebuilt, also smoked a great deal.

Also what grade engine oil are you using? It should be a quality 20/50.

Was the engine rebored or honed? Has it had new rings?

I'll ask the obvious first..... You are closing the choke aren't you?

"Quite a bit of port work done" - hopefully not cut into an oil passage ?? What head is it? Were new valves fitted as well as new guides? What other work was done to the engine??

Hi everyone,
Just got home and am just answering your replies. Thanks again everybody,i don't get much of a chance to reply quickly as i'm usually working away, so please don't think i'm ignoring anyone!
I have started with the block which at some point has been bored out to 60 thou,so have had the bore honed and have had cooper s pistons fitted, (the engineer fitted the rings) then i fitted the pistons but had a few problems as they didn't want to go in easily, so may have broken a ring in the process? who knows. I was talking to Rod taylor who runs the mini place at southam and he said that on some engines the timing chain breather pipe needs to run to atmosphere as in some cases they do not like running to the carb......... so thinking this might be my problem i have re fitted the head without the breather on the carb,but just a few hundred yards down the road realised that it was chucking the new oil straight out the breather all over the engine!! so to get home i replaced the pipe back on the carb but the engine refuses to tick over now,looks like a more serious problem,hope somebody can help!

Thanks again
Andy

" Cooper S " pistons will only fit a 1275 engine.....is that what you have ? Does sound like HUGE pressure in the block. Take the oil filler cap off and rev up the engine - is there a plume of smoke/fume from the filler hole?? You still don't say which head it is ??? That advice about the breather is just nonsense..... you MUST breathe into the carb - or direct into the manifold.

Rod should be able to sort your engine, however my side valve was a new experience for him.
I assume that you only asked Rod for advice and that he did not do the machining.
My money is on you breaking the piston rings, did you have a good piston ring compressor?

Hi,
Yes it is a 1275 with the standard head that has been gas flowed and has had new guides plus hardened valve seats, i ran with the same sort of engine last year and had the breather running to the carb and it ran with no problems. Rod told me that a lot of their mini engines had the breather running to atmosphere but mine just chucks the oil out,and when it's put back on the carb the engine has a job to tick over. am thinking of getting a compression test done, what do you think?

Andy

It can't hurt but Bmcosses' advice is easier and doesn't need a gauge.
How much force did you use getting the pistons in?

A couple of pistons were a little difficult to push down in to the bores,and maybe i did some damage,but why would that
cause the pressure in the crank case?
Andy

Pardon my ignorance but
What is bmcosses??
Andy

You haven't told us the engine size - is it a 1275 engine? And broken rings means the combustion gas will be blowing straight down into the crankcase - causing pressure there - which in turn will blow oil up past the broken rings on other pistons and cause the heavy oil consumption. My 'test' is described above.......

Sorry bmcosses wasn't thinking straight,i've got a spare take off from manifold,what if i connect to manifold then block
off the carb inlet?
Andy

Yes as i've said it is the 1275 from mg midget
regards Andy

Do the filler cap test......it only takes two minutes. Noted - 1275 engine - so crankcase breathing will be very important, bothe from the timing cover and from the rocker cover. But if there is pressure in the crankcase - no amount of 'breathing' will fix it. I would pull the pistons for inspection - asap........

I will do the test you have suggested tomorrow and will connect to the manifold then start from there,and will let
you know what happens.
Andy

What do i do if it does smoke and what if it doesn't?
Thanks

Connect to the manifold won't work.....unless you have a restrictor with a 1/8" hole. But it's not a cure for broken rings - pull the pistons - either way - you must check the rings are ok.

then i fitted the pistons but had a few problems as they didn't want to go in easily

Did you check/adjust the end gap on the rings before you installed them?