Morris Minor Owners Club

I'd agree. It's the same dipstick that came with the engine. I have the plastic holder as well.

Doesn’t everyone add the designated amount of engine oil when refilling? I do - on fresh engines with unknown history. That way if a dipstick has been changed, it becomes obvious almost immediately. I’ve only found it once, but have had a choice of dipstick when an engine has lost its original...

One thing I can confirm is the reason why the alloy timing cover has leaked, is it has come from the oil seal. The supplier had it fitted the wrong way around. I didn't notice this when first fitting, error on my part.

I've replaced it and fitted it correctly now. Wire rope seal facing the oil thrower as stated in the mg midget manual.

so yesterday i fitted new seals to the alloy timing cover after the old ones blew with 100psi oil pressure. on the subject of that, i managed to removed the pressure relief valve and you would expect it to come out rather easy, well sort of. i replaced it with another i had and it went in smoother. measured length and it came in at 73mm long as per the manual. I spun engine over on the starter and the gauge got to 65psi and wouldn't go any higher. I think that may have resolved that.

On reassembling all the parts i removed, i did a compression test on all 4 cylinders and had readings of around 200 on each. Slightly high, but after shining a torch down the bores, there was some oil in each bore as suspected. I have not refitted the PCV valve this time. Instead i have just blanked it off and have a pipe from the crankcase breather just open to atmosphere now. speaking to another mate who fitted a PCV to his 1275, he had exactly the same issues. White smoke in abundance. He advised not connecting it.

I have got as far as fitting everything except filling the coolant as it was past 5pm when i realised i didn't have any. So the next chance i will have to start the engine might be in the week at some point.

Any comments before i take the plunge?

It may be worth considering fitting a hif44 carb to reduce any crankcase pressure and forgetting the PCV.

i have a hif44 carb fitted to a mini spares water heated manifold. it does have a crankcase breather connection, but i have that blanked off

yesterday i fitted new seals to the alloy timing cover after the old ones blew with 100psi oil pressure.

I thought you said that some dumbo had fitted the oil seal AAF (abbreviation of back to front)?

Re the oil pressure:

There may well have been extra restriction of oil flow if you stuffed everything tight with paste at engine start up immediately after the rebuild. That may well have exceeded the capacity of the PRV with stone cold oil. Oil pumps are positive displacement devices, so the oil flow (from the pump) should be fairly well constant (at constant engine speed) and proportional to the engine speed.

I very much doubt that oil pressure would have remained at 100psi for long and not for the duration of the initial run period before it started smoking, so a red herring I think. Further, oil gauges used in cars were never the best indicators over the whole range.

oliver90owner wrote: ↑Sun Apr 18, 2021 12:27 pm yesterday i fitted new seals to the alloy timing cover after the old ones blew with 100psi oil pressure.

I thought you said that some dumbo had fitted the oil seal AAF (abbreviation of back to front)?

Re the oil pressure:

There may well have been extra restriction of oil flow if you stuffed everything tight with paste at engine start up immediately after the rebuild. That may well have exceeded the capacity of the PRV with stone cold oil. Oil pumps are positive displacement devices, so the oil flow (from the pump) should be fairly well constant (at constant engine speed) and proportional to the engine speed.

I very much doubt that oil pressure would have remained at 100psi for long and not for the duration of the initial run period before it started smoking, so a red herring I think. Further, oil gauges used in cars were never the best indicators over the whole range.

yes your correct, the oil seal was fitted wrong. I replaced the other seals when i removed the cover as for the price of £5.38, it was an easy decision.

i'm agreeing that the paste didn't help to start with (oil is already black and i've not driven anywhere yet) so it didn't help. The oil pressure did drop after a while once warmed up so i'm satisfied thats a true reading.

I think the main issue is the PCV valve. as we know it creates a vaccum from the inlet manifold and the more i think about it, it's sucked excess oil and pressure straight from the crankcase and burned it in the combustion process. There will still be oil in there and the exhaust so may well smoke for a little upon running again. I'm not refitting it.

not sure about the pcv valve . any oil blown past the rings would be burnt in the cylinders ,any passing the valve stems would just run back into the sump. The valve is there to remove any excess crankcase pressure via blow past the pistons,and to prevent oil leakage from seals since in a good engine it draws air into the crankcase via the valve in the filler cap and the rear scroll/front cover so the oil can't run out . As to the high pressure....working though it logically where does that have an effect . the pressure ends up at the mains, big /little ends and cam shaft bearings,where the oil is released into the crankcase under no pressure . It has no effect on the pressure inside the case or front timing cover,If you have oil in the cylinders can.t see how that is because of high oil pressure, it has to be getting past the piston rings .
Not sure the valve or pressure is your problem unless 'I'm missing something.

pleased to say that i have resolved the heavy white smoke from the engine. Upon strip down and further investigation, i found the following
so the PCV valve was sucking oil from the crankcase and then going straight into the cylinder. I have binned the idea of a PCV valve. Not sure who suggested it, but it didn't work for me. The confirm now that the engine doesn't smoke at all.

on the subject of the high oil pressure. I removed the oil pressure valve and swopped springs with a new one and now on start up the pressure is at 70psi. When fully warmed, it idles at 45psi. I would expect slightly higher readings on a new built engine. all i have left to look at now is a small leak at the top of the timing case. Can't quite see where from, but near the water pump. maybe a loose bolt?

good news is it isn't rings or any other major issue.

thanks for input i'll keep you updated.

The oil pressure sounds about right to me, have a read of https://www.calverst.com/technical-info ... oil-pumps/

i've read that before, but defiantly a good read. i'm expecting strange readings as it's a tight engine to start with. With time, it should be normal readings. this is why i fit the pressure gauge.

i decided to fit a new oil pressure valve and switch this morning. I also found a small leak which was coming from the oil gallery plug where i hadn't screwed it in tight enough. (schoolboy error on my part).

so all seems good now. I have 70psi cold and 40psi hot. The engine is a little tight but i'm happy now. Zero smoke and it idles nicely. Over the coming weeks i shall road test it increasing the distances.