how are ''big rig diesels'' so durable? - Page 2 - PeachParts Mercedes-Benz Forum

rickjordan · #16 12-17-2003, 12:45 AM

As it has been mentioned, alot of wear and tear happens from constant cold starts, and shutting the enigne off, before the engine gets up to operating temp. It's not so much from "stop and go" driving. Look at taxis, in NYC there are Lincoln Town cars with 400,000 miles on them. These eninges are always running or shut off for very short periods of time. These are gasoline V-8s.

leathermang · #17 12-17-2003, 10:37 AM

"Would one of those devices that circulate the motor oil before starting extend the mileage enough to make it worth the cost of installation?"---DCM

It depends on the cost of the installation and the attitude of the owner towards his car...
I have long wanted one on my cars.... but the ' bought' ones I saw were like $500 ...
Then on some cars there would be a concern as to the " plumbing' .... you don't want it to negate good features of the system you already have...
But a system which makes sure the bearing surfaces of your engine have oil pressure to them before any load is put on them sounds like a good thing to me.... lots of aircraft and industrial engines have one....
To me it would seem that this group of people would be prime candidates for a pre-oiler... but many argue when I mention them....

#18 12-17-2003, 10:57 AM

I definitely don't want to get an oil discussion going, but are you all familiar with the AMSOIL system? I don't know anything about it much, except a buddy of mine installed on on his old Ford F-350 diesel.

Any insight or experience about that system, I'd appreciate. Wondered if it made sense on my 300SD.

sohj · #19 12-17-2003, 12:32 PM

GoWolfPack: I thought AMSOIL only did oil and synthetic and other similar type products. I've never seen a "system" from them.

Of course, as most here know...there's a lot I don't know.

leathermang: If I could fit it in the engine compartment, I'd put in a pre-oiler. In a heartbeat. Any small ones out there?

prb51 · #20 12-17-2003, 12:36 PM

I have a seven year old cummins 5.9/12 valve head. Another reason for longevity is the valve train is operated by gears run off the crank - no internal belt or chain. These run in an oil bath and I've never heard of anyone having a prob with valves or the gears. Don't stop it let 'er run.

BoostnBenz · #21 12-17-2003, 12:57 PM

Funny the preoiler topic came up I was mentioning this idea to my uncle, he paused for a moment and said back when he worked at pontiac he was going to market one but people seemed to think it wasn't a worthwhile idea so he dropped it. I thought about it a little bit but I don't know how it could be plumbed in. Easiest place would be a oil cooler line but that'd make a pressure drop which isn't good. Really we should wait for the glow plugs to go anyway so why not let an oil pump get everything else ready at the same time?!? I wonder how it'd work if attached to the oil filter housing, hmm....

I presume by amsoil system that you mean a bypass filter, yes those would help quite a little bit for wear when the motor is going, but mainly it helps the oil last longer. However I don't believe they have any sort of preoiler, I've never actually seen one.

Wow that is a pretty interesting fact there prb51, I never knew that the CTDs did that. Are the 24V versions the same?

#22 12-17-2003, 03:09 PM

There is nothing WRONG with a preoiler, but there seems to be no practical benefit. The reason I say this is that only the crankshaft, its bearings, and the camshaft bearings and journals benefit. The pre oiler really does nothing significant to prevent cylinder wall wear during cold start.

Since the reason an engine usually is taken apart is cylinder/piston/ring wear, valve related problems or head gasket problems, the preoiler really does nothing for the portions of the engine that usually cause the need for overhaul or repair.

This is the reason that I've never pursued a preoiler.

Have a great day,

sohj · #23 12-17-2003, 03:13 PM

Quote:

Originally posted by LarryBible
... The pre oiler really does nothing significant to prevent cylinder wall wear during cold start....

silly question #8679: Is there anything that would prevent it?

Gilly · #24 12-17-2003, 05:09 PM

We have some buses at work that we are turning over to the charter department, where they actually will get LESS miles put on them than doing "line run" work. The reason? They are approaching 500,000 miles, and the lease is up at that time, we have to pay a per-mile penalty when they go over 500K. They are only about 4 years old. Our highest mileage coach is at about 1,750,000 at this time. It's an 8-71 Detroit, originally had a 5 speed manual, got converted to an Allison automatic. I think it was made in the early 80's. Doesn't get used much now, it was converted to an "Executive Coach".
For buses used for line-run work, they'll accumulate about 150,000 per year. I'm sure some of these long haul semi's get more on than that.

Gilly

BoostnBenz · #25 12-17-2003, 05:55 PM

Leaky injectors could lube up the cylinder wall.

leathermang · #26 12-17-2003, 05:56 PM

Yes, there are small ones ... a google search should bring them up... I think JcWhitney even carried them at one time...

Larry,,, this is one time when your statement may not be correct... with the oil squirters in the turbo units.. I wonder if the oil might get to the cylinder walls... if the oil system is pressurized before start up...

However, your regular na-saying with regards to the value of preoilers leaves open the question as to why aircraft and industrial engines have them....

BoostnBenz · #27 12-17-2003, 06:07 PM

I guess it would vary where the piston is on the stroke, if it is near the top I'd imagine the oil squirters would help things out but if at bottom it probably wouldn't do anything. Then again there will also be no delay in the oil pump sending oil out since it is already there.

I wonder if I could make one with my talon's old fuel pump then wire it to go on with the GP relay.

OhioMercedesBoy · #28 12-17-2003, 07:49 PM

Quote:

Originally posted by Gilly
We have some buses at work that we are turning over to the charter department, where they actually will get LESS miles put on them than doing "line run" work. The reason? They are approaching 500,000 miles, and the lease is up at that time, we have to pay a per-mile penalty when they go over 500K. They are only about 4 years old. Our highest mileage coach is at about 1,750,000 at this time. It's an 8-71 Detroit, originally had a 5 speed manual, got converted to an Allison automatic. I think it was made in the early 80's. Doesn't get used much now, it was converted to an "Executive Coach".
For buses used for line-run work, they'll accumulate about 150,000 per year. I'm sure some of these long haul semi's get more on than that.

Gilly

Shoot, we have 2 routes here at school where we rotate busses off of because it is so long. We average across the board.. probably 75-100K per bus a year. Depends on if it is in the shop a lot... our mechanics aern't the fastest in the world.
~D.J.~

kerry · #29 12-17-2003, 08:34 PM

In a previous discussion, I think a pre-oiler without a pump was brought up. Apparantly they are used on some stock cars. There is a container, pressurized when the engine is running. It stores the pressure and releases it on demand prior to starting. Seems simpler than the expensive pump systems.

BoostnBenz · #30 12-17-2003, 09:34 PM

I don't know if that'd be simpler, it would probably take a bit more room for the air tank to hold the oil, then how do you get the right amount into the drain pan? Also when you changed the oil you'd have to drain it as well.