I'm in the process of buying an LPG dedicated F-350 (1982 460)

What oil will give the longest engine life? Local concensus seems to be a 20w-50 due to higher temperatures of a propane engine, but I'm not so happy about cold-start circulation.

In the 385 series forum, 10w-30 was favoured, but then this is an LPG, not gas engine.

What does everyone here feel? Thanks

 

wouldn't the LPG run cooler

my uncle uses 10W30 and I think the propane company he works for uses the same in there fleet trucks

Those engines run extremely clean too. The oil appears to stay cleaner a LOT longer.

 

No - hotter & drier. Often an upper-cylinder lube system is used, both for lubrication & also to help with valve & seat life.

But, yes, very clean, with longer oil change periods.

Chevron have advised me to use Havoline Formula 15w-40

Thanks for the reply

 

Pretty much any synthetic would work and give very long interval oil changes

 

I would also recommend the 15-40. I use it in everything I own except the modular motor. You might also try a 5w-40 synthetic, it would have high heat resistance and good cold flow.

I'll move this to the oil and lube forum.

 

A 15w40 would be best or if cold weather is a concern try 5w40.

 

Why would propane run hotter and drier, whatever that means, than unleaded gasoline or E10 with EFI? That sounds like "old timers" comparing LPG with leaded gasoline and a carburator. The 20W-50 recommendation furthers my theory that you have been talking to folks who havent looked at automotive technology since the 1970's.

EFI engines run "lean of peak" most of the time. That is pretty "dry", I guess. Unless you disable the EGR, combustion temperatures should not change significantly.

10W-30 or 5W-30 is the Ford recommendation for late 460's. Unless PROVEN otherwise, stay with that for maximum engine life.

Jim

 

A low ash oil if you can find one. Will this engine run 100% on LPG? Detergents are not necessary in a LPG engine. A low ash oil will keep valve deposits to a minuimum with these engines. If you run this truck on gas too then just stick with a detergent oil. My 460s are on irrigation motors out here. Run them in the summer an use Sae 40 low ash. I can only get that oil in single weights however. Id think a 20 wt oil would work good in the winter time. Or if you can get a 10w-30 oil go that route

 

Rotella 5w-40 is a very robust and hard to shear oil. Better so than it's 15w-40 dino brother.

 

Thanks for all the positive input.

The F-350 is unfortunately no longer for sale, so I'm hunting again - but whatever I buy will probably be LPG (sooner or later) anyhow.

Thank you

 

I like Chevrons suggestion for a crankcase lube.

The "Dry" part has to do with gasolene having upper cylinder lube/s blended in, where as LPG doesn't offer any upper cylinder lube.

The lubricant choice has a lot to do with the lubes ability to handel heat & the ash quantity & content, of the lube that gets cooked, so combustion chamber deposits & piston ring lands don't get clogged up with deposits that the lubes detergent/dispersants can't handle.

So many things need to be considered in lube choice, it isn't just one aspect, like viscosity, or ash, or base oil type, the whole lube recipe needs to be matched to the job at hand!!!!

Just some more thoughts for pondering.

 

LA or MA (probably the ma due to the higher speeds of the engine) natural gas engine oil. Straight 40 weight. Take your pick. Texaco GEO 40 MA, Chevron HDAX 40LA or MA, Shell Mysella 40LA or MA. This is what Compressco runs in their Ford 460 enginne/compressor package engine. Wellhead gas is much more volitale than pipeline quality gas, so there is alot of propane and ethane as well as butanes in the wellhead gas that poweres these engines. Shell did a very detailed (I made alot of money from it) study of cylinder heads and cylinder head failures on Waukesha VHP heads several years ago. They came up with the speed (1000 rpm, which is considered a high speed gas engine compaired to the 300-330rpm slowspeed gas intergral compressors) that the Waukesha, White Superior and Cat engines run, a medium ash oil was much better suited to 4 stroke head and valve life, where as the 2 cycle slowspeeds have no valves, the carboning of the ports was much more criticle to control, so low ash is what these engines benifit from.

 

Ashless oils also tend to lack ZDDP, not just detergents and buffers (TBN). That is probably why the four-strokes did better on medium ash oils. Two-strokes are a different animal and dont relate to a 460 at all.

How is wellhead gas treated before burning? It must have some moisture and acids.

Jim

 

Its not treated, until it reaches a midstream facility. Which dehydrates and strips all the other components out to get it to meet pipeline quality standards. NGL's Propane, Butane, Ethane, Hexanes, Co2, Nitrogen, and Heptanes. Your statement on 2 strokes is kinda loaded. Yes they do when it comes to oil and the fuel they are running. Big 2 strokes have oil ports in the powercylinders and use crank case oil. However if you want a rundown on what is in Chevron HDAX 40LA, which is what we run in our Cat Nat Gas engines, I'll type in some specifics.

moly 349 ppm
boron 6 ppm
magnnesium 4 ppm
calcium 1442 ppm
phosphorus 293 ppm
zinc 343 ppm

 

Roller cam? How else would they survive on that little barrier lube, even with the moly.

Jim