Thread: Oil consumption (history)

psuedo two stroke?

I have a tech. college text book from 1960 on internal combustion engines and it states that acceptable oil consumption in a passenger car used in light to medium duty service as applicable to a private or family car was from a pint to a quart per 1000 miles. Any usage greatly in excess of this it said, should be investigated as this level of consumption was a sign of a worn or faulty engine.
Oil change intervals ( passenger cars) then were usually 1000 miles for engines and 5000 miles for transmissions and diffs. Grease jobs were recommended variously as either 500 miles or 1000 miles, with some items having a service recommendation of weekly. Oil filters in the cars that had them, were usually changed at 5000 miles. This is why all service stations had lubritoriums.
Engine design, materials, filters, fuels and oils had come a long way by then since the start of WWII. I well remember the cars of the 20's through most of the 50's that had the heads off just about every 10,000-20,000 miles for decarbonising and often a valve grind at the same time. Rings and bearings often done at 30,000 to 50,000 miles. My father and uncles would recommend never to buy a car that had done 100,000 miles as they were generally badly worn throughout by then unless the car had been carefully and extraordinarily well maintained.

JD, the big Wrights, P&W's, and Merlins that I worked on in the early sixties were prodigious burners and leakers of oil. I never had anything to do with the Bristol sleeve valve aero engines, but ex-navy types who did reckon their oil usage was amazing. The diesel engined trucks we had also used a good bit of oil and were expected to as lube oil and distillate are closely related fluids. I remember those de Havilland engines as being reputed oil burners but never had anything to do with them that I can remember. Maybe something to do with the piston rings of the time and the engines being "upside-downers".

When in duispute with a Rover dealer about 2 years ago over our engine I recieved a reply from Land rover Australia that they considered up to (I think from memory) 1L per 1000km's as normal.

Mine uses about half a litre between oil changes and works between them so I'm happy but what they considered acceptable was a bit scary at the time!

While to underside of my 215,000km diesel get a bit moist it does not drop oil and it doesn't use oil between changes.

Interestingly the jag V12 engines are considered to be relatively high tech yet its main rear crankshaft oil seal is still made of rope and needs to be run regularly to keep the oil in it so it will not dry out - if it drys out, then the engine is started, the friction burns out the seal.

Gazzz

Nothing wrong with rope rear main seals, provided they are installed correctly. I had a Holden 308 with one which did at least 100 000km after I rebuilt it (in my ownership) and never leaked a drop out of the rear main seal. I still keep in touch with the current owner and he has never mentioned a leak either (in some 5 or 6 years).

About 45 years ago I think I was told by a mechanic that Austin A40's oil consumption was considered acceptable if it was below a gallon/1000miles.
My first car was a second hand Austin A40. It had used oil from new and when it got to a gallon/1000 miles at about 40,000 miles, the original owner had rings and bearings fitted just before I bought it and from that day on to about 70,000 when I sold it, the oil consumption (Castrolite I think) in 1000 miles was not even enough to show up on the dipstick. I often wondered why it improved so much. Was the original manufacture or assembly shoddy? Had oils improved in the 20 years? Was it just a fluke or was that sort of improvement common?

Originally Posted by vnx205

Austin A40. Was the original manufacture or assembly shoddy?

And you need to ask??

Originally Posted by Brian Hjelm

I have a tech. college text book from 1960 on internal combustion engines and it states that acceptable oil consumption in a passenger car used in light to medium duty service as applicable to a private or family car was from a pint to a quart per 1000 miles. Any usage greatly in excess of this it said, should be investigated as this level of consumption was a sign of a worn or faulty engine.
.............
Engine design, materials, filters, fuels and oils had come a long way by then since the start of WWII. I well remember the cars of the 20's through most of the 50's that had the heads off just about every 10,000-20,000 miles for decarbonising and often a valve grind at the same time. Rings and bearings often done at 30,000 to 50,000 miles. My father and uncles would recommend never to buy a car that had done 100,000 miles as they were generally badly worn throughout by then unless the car had been carefully and extraordinarily well maintained.

JD, the big Wrights, P&W's, and Merlins that I worked on in the early sixties were prodigious burners and leakers of oil. I never had anything to do with the Bristol sleeve valve aero engines, but ex-navy types who did reckon their oil usage was amazing. The diesel engined trucks we had also used a good bit of oil and were expected to as lube oil and distillate are closely related fluids. I remember those de Havilland engines as being reputed oil burners but never had anything to do with them that I can remember. Maybe something to do with the piston rings of the time and the engines being "upside-downers".

A good example of the changes you mention in my experience is the Citroen D series engine. I have been closely associated with these since 1962. They redesigned the engine in 1967. The older engine was lucky to do 80,000 miles before needing pistons and sleeves, although interestingly they rarely needed the crankshaft reground at this time. When the new engine came out a friend of mine who was a specialist Citroen mechanic, based on his experience with the earlier engine, stocked up with a set of pistons and sleeves. He still had them when he retired in 1995, having never had to even take the head off one of those engines - 200,000+ miles is not uncommon for them. They are basically the same engine but shorter stroke and five bearings and an oil filter. (cross-flow pushrod valve gear, wet sleeves, alloy head).

The De Havilland engines you refer to - the oil useage is perhaps partly due to the inverted design - for example the rocker boxes fill through the pushrod tubes, but have no scavenge pump, just an overflow! But you need to realise it is a very old design. The original Airdisco engine was half a WW1 Renault V8 with a new crankcase. When supplies of this ran out De Havilland started building a copy of it, the Gipsy. This was later turned upside down and enlarged as the Gipsy Major, leading later to the six cylinder Gipsy Queen and twelve cylinder Gipsy Twelve - but they were all ultimately derived from the Renault of about 1916. The four and the six continued to be fitted to new aircraft into the sixties and possibly even the seventies. The Gipsy Major is the aeroplane engine built in largest numbers in Australia, about ten thousand from memory, to fit the Tiger Moth (1035 built here - extra engines were for replacements). I believe these engines were built mostly by General Motors Holden (certainly the one in my plane was) and smaller numbers by the Tasmanian Railways.

John