Morris Minor Owners Club

Hi, I’m new to this site, and call me a heathen if you will, I own a Marina, which I know few of you will have broken up for your Minors, but I digress, my problem is with my Marina, 1275cc A series engine, and I have an oil burning problem with it that is driving me crazy, it’s had the head refurbished, new guides, seals, etc.., new BK450 head gasket, the bottom end has never been touched as everything looked fine, I’m getting 160-165 psi dry on all 4, and 175 psi wet, breathers seem clear, tested by blowing through the seperator on the chain cover, no smoke coming from either dipstick or oil filler hole and healthy suction at the filler hole as well, yet I’m getting fairly heavy smoke out of the tailpipe, drive it gently and it’s ok, give it some welly and the smoke starts coming, I realise despite the apparently decent compression that my oil rings could be toast, but I was looking for a fresh pair of eyes that could maybe think of something I’ve missed or something glaringly obvious that I’m not seeing, TIA. Just to add, driving wise it pulls great and has plenty power.

I've had two smokey 1275 Marinas. Both a long time ago. One was a '72 with 80,000 on the clock. That one was a rings problem. Ran great most of the time but occasionally died on me and then would turn over very fast on the starter as if there was no compression. Leave it fifteen minutes and all fine again.
The other was a '76 with 60,000 on the clock. That one was a breather issue which I never managed to cure. Clean the breather. Fine for a few miles, then smokey again.

I don't think its unusual. Having worked for a British Leyland dealership in the 1970s I recall Marinas often using great quantities of oil even when they were brand new We were regularly fitting replacement "Gold seal" engines to them under warranty. I had at least 2 as company cars and checking/topping up the oil was a weekly job on most BL cars back then. If they didn't drop oil they probably burned it - or both. We used to say that if they weren't dropping any oil you'd better check the dipstick because the sump was probably empty
The cars in the showroom still had a driptray underneath the engines in those days.

If you've had the cylinder head rebuilt properly, it is almost certainly time to think about the bores/pistons/rings I'm afraid.

First, remove the crankcase breather pipe, to wherever it goes, and then check for crankcase breathing.

Is the smoke blue or black? What colour are the plugs after running? Same on all pots?

How much oil does it consume? Used less leakage, so not including any leaks.

Seems as though the rings may be oil pumping - possibly the scraper ring(s) stuck. What oil is being used - detergent or non-detergent?. It can make a difference.

Possibly the compression ring grooves are worn badly - either need new pistons, a repair job (and wider rings or inserts) or a rebore if the bores are oval.

If all the work was done to alleviate this problem, it might appear that either the claimed work was not carried out (or done properly), or was not actually needed in the first place. There are too many places that simply jump to unsubstantiated conclusions and carry out unnecessary work, then disappear or deny any responsibility for charging without curing the initial problem.

I would suggest that the oil control rings are stuck or shot.
As a first stab at the problem I would change the petrol engine oil to diesel engine oil which has a high detergent content which should after a period of running loosen and remove any stickiness of the oil control rings.
If that does not work I am afraid it means the head and sump off and the pistons drawn and examined for faults.

Yeah, you’re all confirming what I was thinking, which is a real bummer, as I’ve only just put the head back on after getting the guides and seals done, they were bronze manganese guides that were put in, and was all done right, the thing is, the heads been off twice, first time because the head gasket had failed, and it started smoking then about 50 miles after, but I discovered that the head gasket was leaking oil into the cylinders by means of an endoscope through the plug hole, so I’ve changed it again, this time it’s sealed right, still smoking, it didn’t smoke before the head was removed the first time, which is what is really puzzling me. But as you all say, my oil rings are probably stuffed.