One other comment for the guys with gasoline engines and in particular carburetor engines.

When cold the choke is full on and there will be a lot of gasoline going into the engine. This will wash down the cylinder walls and collect in the crankcase during a start in cold weather. If warmed sufficiently, the gas will evaporate from the crankcase fairly quickly but if not, and repeated starts occur, the oil will very quickly become contaminated and thinned with gas.

When I was in the cold country (Chicago area) I repaired many engines that were repeatedly started and not driven during the cold. The oil in the pan was always a couple of quarts higher then normal and it was very thin from all the gas that accumulated there. Bearing and rings were gone in no time.

Another tip that we used on our diesel heavy equipment that was stored (and I even do this in California when I leave the Barth sit) for 30 days or more, I disconnect the fuel solenoid and crank for a brief period to get a show of oil pressure before I allow it to fire.

quote:

Another tip that we used on our diesel heavy equipment that was stored (and I even do this in California when I leave the Barth sit) for 30 days or more, I disconnect the fuel solenoid and crank for a brief period to get a show of oil pressure before I allow it to fire.

A diesel tractor I had had a manual fuel shut-off. After turning on the glow plugs I always cranked twice for about five seconds with the shut-off out before starting. That also heated the cylinders and helped the cold start.

Most of our equipment at work would not light off until oil pressure had been satisfied. Some had pre-oilers. A while back, in cold places, some had oil dilution systems where gasoline thinned the oil so it would flow better until warm. Then it cooked off. I have a pre-oiler, but have not installed it yet. So, I just do the crank thing, too.

An old Wright engineer told us that 90% of engine wear is on cold start ups.

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Originally posted by bill h:
An old Wright engineer told us that 90% of engine wear is on cold start ups.

Back in my old Navy days as an aircraft mechanic and flight engineer, we were taught to turn over the engine until we had positive oil pressure and fuel pressure before we even turned on the magneto.

Nick

quote:

Originally posted by Nick Cagle:


Back in my old Navy days as an aircraft mechanic and flight engineer, we were taught to turn over the engine until we had positive oil pressure and fuel pressure before we even turned on the magneto.

Nick

I guess they didn't have shotgun starters then, huh?

If they were round engines, the rotation assured that there was not hydrostatic lock, as well.

Speaking of round engines, I got to see and hear a radial diesel aircraft engine last weekend.

Bill H, Mainly 3350's 18 cylinder, 2 row radials. Aircraft P2V, EC-121, AD-5 (changed to A1E) All had 3350's.

Nick

Wow. Neat airplanes. I never learned to love that engine, though. Kind of a P&W guy. Jug changes on on flight-interrupted 3350s provided a lot of field trips and overtime, though.

Sorry to get in late on this thread. I agree that we need to get the engines loaded and up to temp on all engine parameters to be helpful in keeping seals and engine happy. In my studies over the years, high quality synthetic oil (read pure synthetic, or high percentage syn) however does make a difference in that the pure synthetic oils will not emulsify with the water in the engine from condensation. There are many studies done on this that can be found on the web. Essentially if you have a high quality syn oil and -don't- get your engine up to heat to cook the water out of the engine, it will just lay on top of the oil with out much if any emulsification. Petro oil will emulsify or 'blend' to a small amount with the water. And that emulsified oil loses much of it's lubricity.
Sorry for the long post but this is important for those in high humidity areas. The syn oil is very expensive however with by pass filters and oil analysis you can mitigate the extra expense.

quote:

Originally posted by Stratosurfer:
Essentially if you have a high quality syn oil and -don't- get your engine up to heat to cook the water out of the engine, it will just lay on top of the oil.

Is synthetic oil heavier than water?

The base stock, whether synthetic or dino, doesn't cause emulsion; the additive package does. Contemporary motor oils may have additive packages >30% by volume.

The emulsion has the base stock as the continuous matrix, so that water is kept from contact with metallic parts. (An ashless detergent-dispersent also coats the metals for further protection). In a well-formulated additive package, the water degrades the lubricating properties insignificantly, especially since the viscosity is higher when cold, when the water is present. Gross contamination, of course, cancels all bets .

I know of no general-use lubricating oil denser than water, so the water would sink; in many applications (such as steam turbines), this is desireable, as the water can be drained off.