How come gas vehicle engines don't burn oil?

[Passattdi]

. . .

Oil manufacturers make a difference to the amount of oil burned. Made the mistake of trying mobil 1 for diesels in my 2012 TDI Passat. For that 10000 mile change it burned almost a quart. Changed back to the dealer sold Castrol and went back to burning no oil between changes. Go figure.

 

[Passattdi]

Have heard of Bonami dumped into the engine intake to "hone" the cylinder walls. Bonami was a powdered abrasive household cleanser. Don't know if it's still made.

Years ago,, Honing typically created cross hatching in the cylinder wall that help to retain a miniscule amount of oil on the walls and since it is cross helps in retaining oil by the rings. It also allowed the rings to seat more easily. Today machining techniques hold tolerances significantly tighter than 50 years ago... provided it is done correctly.
Bonami would create slight verticle scratch honing that would allow both oil and compression to seap by.

 

[Grumpycat]

Honing does help hold oil on cylinder walls and provides a visual indicator of wear. Many high performance engines alloy aluminum and controlled cooling during casting. Cylinder bored, polished, then acid etch to remove soft aluminum leaving hard silicon carbide and whatever. This surface also holds a film of oil but would be destroyed if honed. Is not the kind of thing the local machine shop should attempt. There are several specialists nationwide to ship cylinder/block to be resurfaced by etching or more commonly plated.

The magic of machining tolerances is in creating round cylinders and rings which do not need to “break in”.

 

[5030]

Honing does help hold oil on cylinder walls and provides a visual indicator of wear. Many high performance engines alloy aluminum and controlled cooling during casting. Cylinder bored, polished, then acid etch to remove soft aluminum leaving hard silicon carbide and whatever. This surface also holds a film of oil but would be destroyed if honed. Is not the kind of thing the local machine shop should attempt. There are several specialists nationwide to ship cylinder/block to be resurfaced by etching or more commonly plated.

The magic of machining tolerances is in creating round cylinders and rings which do not need to “break in”.

Reminds me of the old Vega oil burners............

Actually, all internal combustion engines 'consume' oil, it's just the amount is so small in a modern engine that you won't notice the drop on a dipstick but they all do none the less.

 

[5030]

I remember that stuff.
"Hasn't scratched yet".

Any cleanser works actually. Kind of SOP on a high hour 2 stroke Detroit's where the bores got glazed. You gave them a shot of cleanser and they were good to go again. I've used everything including Comet with chloronol.

 

[radios1]

Honing does help hold oil on cylinder walls and provides a visual indicator of wear. Many high performance engines alloy aluminum and controlled cooling during casting. Cylinder bored, polished, then acid etch to remove soft aluminum leaving hard silicon carbide and whatever. This surface also holds a film of oil but would be destroyed if honed. Is not the kind of thing the local machine shop should attempt. There are several specialists nationwide to ship cylinder/block to be resurfaced by etching or more commonly plated.

The magic of machining tolerances is in creating round cylinders and rings which do not need to “break in”.

there's another trick too.. tapering the cylinder bores at the bottom so it makes a tighter fit..

 

[5030]

According to my cousin, who has worked on the railroad for 30 years, they use oil sampling to determine oil change intervals. Depending on the type of service, switcher or road unit, it can vary quite a bit. A big EMD or GE prime mover holds around 250 gallons of lube oil, and there is an oil sump drain with a quick connect fitting, usually above the fuel tank, for draining the oil.

Last winter a couple of SD40-2s were left running for a weekend on a siding in town. I walked out and looked them over, one unit was dripping oil out of the sump under the engine, obviously from an oil leak, probably leaked 5 gallons over the weekend. Both were built in the mid 70's, and were getting a little long in the tooth, but were still pulling their weight, so to speak.

Locomotives have always fascinated me, as they are amazing machines.

ConRail don't change the oil, they add instead. EMD's are basically 2 stroke Detriot's upsized.

 

[Grumpycat]

Reminds me of the old Vega oil burners............

Actually, all internal combustion engines 'consume' oil, it's just the amount is so small in a modern engine that you won't notice the drop on a dipstick but they all do none the less.

GM was too cheap to do what everyone else knew had to be done to cast an aluminum block. Porsche, Mercedes-Benz, the Japanese, everyone knew electric heaters were required inside the cylinders to slow the cooling and control the metallurgy of the formed grains. Done right produces a superior cylinder.

 

[fried1765]

The thread title is funny
Back in '74 I had a 1966 Dodge Valiant slant 6 (bought in 73 for $100) that I drove from Vt to Ca and back in '74. When I started out I was getting almost 200 miles/quart. By the time I got back about 6 months later I was only getting 40 miles/quart.
Some gas engines do burn oil!

The best explanation for that is: It was a Chrysler product:laughing:!

 

[fried1765]

^^^^
I've often wondered how that monitor would match up with an oil test... but I've never been curious enough to pay and find out.

I did oil samples on my boat twin diesels, and their transmissions.
The sampling saved my transmissions.