BMC 1.8 using oil

[Cheshire cat]

My understanding is that running in oil provides basic lubrication but doesn't have the complex molecules of modern additives. As a consequence bore glaze doesn't occur and everything beds in thereby avoiding excessive oil consumption.

 

http://www.millersoils.co.uk/commercial/tds-commercial-vehicle.asp?prodsegmentID=741&sector=Fleet

 

I'm not recommending any particular product. I just knew Millers would do one.

[Tony Brooks]

So. Would you put some kind of filter in the bottle. Thinking about a bottle with 2 tubes. One in and one out, and some kind of filter to catch the oil

 

If you want to link the bottle to the outside world then you will have to d=seal both pipes into it. Otherwise the fumes will just escape from any gap between bottle and pipes. This is why i said just stick it in a bottle.

 

The wire gauze if used acts as a mist trap and also a flame trap in case of a back fire igniting the oil mist in the breather. It would be exceptionally unusual for a diesel to back fire. I would say given a tall enough bottle you do not need a gauze. The early 1.5s only had a baffle (and the 1500CC B series petrol engine). A one serving coke bottle or a 2 pint &above milk carton will be fine.

 

I am at something of a loss on this one. You are using a lot of oil, there are no leaks, the oil in the filter suggests it coming from the breather system yet you said there are not many fumes. There has to be back pressure to blow oil out of the breather., mots back pressure comes from piston blow by, so I would expect lots of fumes.

 

[jimfin]

 

 

 

I am at something of a loss on this one. You are using a lot of oil, there are no leaks, the oil in the filter suggests it coming from the breather system yet you said there are not many fumes. There has to be back pressure to blow oil out of the breather., mots back pressure comes from piston blow by, so I would expect lots of fumes.

 

Thanks for the input Tony. When I say there are not many fumes, the breather pipe goes into the air filter housing and sucks fumes and oil into the intake.

[Tony Brooks]

So as a vital part of the diagnostic process how many fumes are there when the breather has been removed from the air cleaner or when you take the oil filler cap off? My guess is that it will be a lot of gasses moving. If that is the case its almost certainly piston blow by and that would be cause by either the piston, bores and rings being OK but not yet run in or a problem with the pistons, bores and/or rings.

 

As the cylinders were not re-bored, the rings were not the correct ones, such honing that was done was not with a professional honing machine and I do not remember any references to you either using ridge dodger top rings or removing the cylinder ridge I suspect running in with running in oil may well turn out not to be enough but that must wait until you have tried running it in.

[Flyboy]

When you did the overhaul, did you check the bores for 'ovality'. If they are not round they will never bed in.

[Tony Brooks]

Or for taper come to that. If they are barrel shaped then just as with ovality the new rings may never seal.

[jimfin]

I did not check for ovality. I had not got an oil problem before the overhaul, and this was with piston ring gaps of 3mm!!!

 

To help running in I was thinking of using high revs when starting from cold. I usually run at about 1500 rpm.

[RLWP]

I did not check for ovality. I had not got an oil problem before the overhaul, and this was with piston ring gaps of 3mm!!!

 

To help running in I was thinking of using high revs when starting from cold. I usually run at about 1500 rpm.

 

The usual method for making rings bed in is cruelty, so yes - more revs

 

Richard

Edited September 7, 2016 by RLWP

[Tony Brooks]

I did not check for ovality. I had not got an oil problem before the overhaul, and this was with piston ring gaps of 3mm!!!

 

 

All that really means is that the cause of the oil in the breather can not be isolated any more until you have tried running the engine in. Although a cylinder/piston problem is most likely you do get pulses in the inlet tracts that MIGHT blow oil leaking down the valve stems back into the air cleaner but it is less likely on a diesel.

[jimfin]

Was just thinking about my problem over the weekend. As you do.

 

With the oil / crankcase fumes been sucked into the inlet this would give lubrication to the bores and slow down or prevent the bedding in!!!

 

What do you guys think?

[RLWP]

Was just thinking about my problem over the weekend. As you do.

 

With the oil / crankcase fumes been sucked into the inlet this would give lubrication to the bores and slow down or prevent the bedding in!!!

 

What do you guys think?

 

Unlikely. It usually just blocks up the filter and makes them run black. Compared to the oil coming up past the rings the stuff through the inlet will be trivial

 

Richard

[David Mack]

 

Would that be 30 pints of oil?

Nobody has picked up on this. If you really have lost 30 pints of oil since the rebuild, then regardless of exactly what is hapening inside the engine, you either have the best part of 30 pints of oil in your bilges, or it has gone up the exhaust in blue smoke.

[Tony Brooks]

I did but as I think he said there were no leaks, did not reply to the question about blue exhaust smoke and has not mentioned the exhaust leaving an oil slick I rather discounted it as a degree of misinformation.

[jimfin]

There is no oil in the bilge. Looking out the back as we motor along, looking at the smoke I would say it is mostly white.

 

I find it hard to tell the colour. On a scale of 1-10, White to black, I would say I am down around 2

 

Is it possible to show you guys a vidio? How would I do this?

[David Mack]

Put it on youtube and post a link.

[cereal tiller]

There is no oil in the bilge. Looking out the back as we motor along, looking at the smoke I would say it is mostly white.

 

I find it hard to tell the colour. On a scale of 1-10, White to black, I would say I am down around 2

 

Is it possible to show you guys a vidio? How would I do this?

White smoke can only be caused by poor compression or late timing

 

Should an Engine start well from cold it is likely that Compression is good

 

If timing is late the oil film in the Cylinder Bores will be diluted by unburnt fuel and cause excessive Blow by

 

Suggest advancing Injection Pump by a degree or two .

 

CT