Engine loading

FF said:

"Even with water temperatures close to 45F (spots in Glacier Bay) the coolant and oil temperatures are in the same ranges."

This is probably good for the engine maintaining its machined shape,
But has is no help for an under loaded engine that may begin to slobber

Click to expand...

You've lost me FF.

sunchaser said:

I shoot both the oil filter and oil pan. The filter runs about 5F more than pan. The coolant temperature, at 175F, is about 20F less than filter once everything hot.

Click to expand...

My coolant tank runs 155°, top of the oil filter about the same.

Make sure to take the temp within a foot of your target. The IR beam spread is about 4 to 1, so that means at 1 foot, you are measuring an area of 3" in diameter.

As far as loading my engine, a Ford Lehman SP135, it has confided in me, that it is quite happy at 1500 to 1800 rpms.
And that if I want to continue crossing oceans, just keep doing what I'm doing, because oil is cheap.

Military Power is reserved for those situations like the inlet at Depoe Bay, when it's Do or Die.

Lastly, I've broken far too many things pushing them to full power for the hell of it.

"This is probably good for the engine maintaining its machined shape,
But has is no help for an under loaded engine that may begin to slobber'
"You've lost me FF."

Slobbering is the result of poor ring sealing due to not enough load to properly press the rings to seal.

Temperature is not the problem, many properly loaded sea water cooled (about 140F) engines work fine , no slobbering , until the block finally rusts thru.

Slobbering?

Well my old car has 297000 miles on her (Nissy’s her name being a Nissan) and compression is down enough to be minus 25% of her power and she likes to shift at a slower pace because rpm dosn’t come down fast like a newer car w full compression. Smoke? .. yea a little. Never noticed it while driving though.

Thought of feeding her a little SeaFoam. In the cylinders for a few hours or overnight to penetrate the rings and desolve or otherwise deal w the deposits in the ring lands to free op the rings and thus restore much of her lost compression.

The whole point is that many old FL’s and similar engines may benefit from such a treatment. A little more difficult w a diesel w/o heaters. Such engines would need to pull the injectors to put in the SeaFoam I’m think’in. Is that true or is there another way? And then w the depression on the piston crowns the SeaFoam may just sit in the depression in the piston and not reach the rings.

And one would want to change oil after to insure there wasn’t too much SeaFoam in the oil. Things like oil seals (such as on crankshaft ends) would need to be considered to avoid trading a smaller problem for a bigger one.

Any thoughts or opinions?

The old car.

Nomad Willy said:

Slobbering?

Well my old car has 297000 miles on her (Nissy’s her name being a Nissan) and compression is down enough to be minus 25% of her power and she likes to shift at a slower pace because rpm dosn’t come down fast like a newer car w full compression. Smoke? .. yea a little. Never noticed it while driving though.

Thought of feeding her a little SeaFoam. In the cylinders for a few hours or overnight to penetrate the rings and desolve or otherwise deal w the deposits in the ring lands to free op the rings and thus restore much of her lost compression.

The whole point is that many old FL’s and similar engines may benefit from such a treatment. A little more difficult w a diesel w/o heaters. Such engines would need to pull the injectors to put in the SeaFoam I’m think’in. Is that true or is there another way? And then w the depression on the piston crowns the SeaFoam may just sit in the depression in the piston and not reach the rings.

And one would want to change oil after to insure there wasn’t too much SeaFoam in the oil. Things like oil seals (such as on crankshaft ends) would need to be considered to avoid trading a smaller problem for a bigger one.

Any thoughts or opinions?

The old car.

Click to expand...

I did this exact treatment on a Lexus RX300 that started burning oil like crazy around 170k miles, it was ~30-40% down on compression on two cylinders and burning oil like crazy. Some engines have a reputation for sludging up the oil passages between the head and the block, I first thought it could have been the culprit and oil was being pulled in through valve stem seals until I did the compression check. I was using 1 quart / 100 miles. It made all of the difference in the world, I was able to get another 75k miles out of the car. I'm not sure why the rings gummed up in the first place, it received frequent oil changes and is a sound engine design but I figured it was worth trying as the engine was practically a lost cause at that point. Complete overhaul parts exceeded the value of the vehicle. A vertical, inline engine would be easier to soak the rings than an slant or v configuration. Small doses added periodically and rocking the crankshaft back and forth to help free the rings was my approach. Seafoam is safe to run in the crank case oil up to a certain percentage. I was essentially working with a lost cause so I ran it with about 2 bottles of seafoam in it for a few hard miles to heat things up.

Ski in NC said:

Often the glazing is not really wear on the liner, but the hone grooves get packed with carbon. Oil control gets sloppy. Often a good hard run will burn the carbon out of the grooves and all is well. An hour or so at 75% should do it.

A 2liter engine at 1800 and making 40hp is not going to have a glazing problem. Even at 20hp at 1800 it will be fine.

It can be a real problem on gennies that run all night and all day at almost zero load at 1800, day after day.

But the issue still is rare. Running a Yanmar JH at hull speed is NOT going to have this problem.

Still good to run it hard once a day. But no need to go to full power, 75% should be fine. Even 50% should clean it up.

CD, don't worry about this.

Click to expand...

Since what I wrote the article that started this I'll chime in.

Tony Athens, a man for whom I have great respect, and I have a difference of opinion on under loading, it may be a result of the engines we see, I suspect many of the ones he works on, because of the coastline and lack of protected waters, are run hard and are commercial, most of my work is with displacement vessels, recreational, that are over-powered and operate often in sheltered waters on the East Coast and PNW.

I have seen engines suffering, if not dying, from the effects of under loading, there are photos of them in the article, generators in particular, especially when used to charge batteries, sometimes running at 10% load. I often go aboard new boats that are being commissioned and in many cases the genset is running, it's powering some lights and little else if it's not in a very warm or cold climate. I look at the hour meter and it has 50 or 60 hours on it, running like this, it's a great way to improperly break in a genset. https://stevedmarineconsulting.com/properly-breaking-in-your-generator-and-why-this-is-important-2/

I also agree that WOT is wholly unnecessary to properly load an engine periodically, running it hard enough to raise oil temp above 180F is one of the goals.

Ski you are very right to point out the that glazing isn't wear, it's a filling in of the cross hatch.

Glazing refers to the appearance, which is smooth, and shiny, ice-like, however, a coating or “filler” of sorts does form. The actual process is broken down into two sub-groups, glazing and polishing (some call it burnishing). In the former, combustion byproducts, as well and oil and fuel, combine and oxidize to fill in the valleys between or grooves in the cross hatch pattern, creating the smooth finish. The effect is usually uniform and it sometimes has a yellowish appearance.

In the latter, carbon deposits on the rings and piston ring lands prevent the rings from floating, and self-adjusting during piston movement, as well as inhibiting expansion and contraction during heating cycles. This leads to excessive and uneven pressure being placed against the cylinder wall by the seized ring, which leads to wear (as opposed to the deposits in the case of glazing). The effect is often localized vertically on one region of the cylinder wall.

The terms are often used interchangeably, and I confess I’m guilty of this, strictly speaking, however, they are different.

I had a 3208NA in my commercial salmon troller that also ran my freezer all night at about idle. Obviously the engine wasn't load too much between nights running the freezer and days trolling at around 1300 rpm. I eventually pulled her and had her rebuilt. Her hours were up towards 20,000. Not sure on total as second hour meter?

Put in the three ring pistons on rebuild. What a difference in oil consumption and smoke on running up the rpm leaving the hook in the morning. Once each day I would run her up to 2400 rpm to load her up.

If I ever had a 3208 again in my vessel I would go for the three ring pistons as soon as a rebuild was indicated through these engines run so well, so long, that might take a long time to get to rebuild time.

On our way to our anchorage today I made note of of the loading on our Cummins QSB 5.9L engine. The engine says that it was running at 29% load (36% max rpm). We typically run around 1450 rpm. I probably should check to see what my oil temps are. Any idea where is a good place to check oil temps with a laser temp gun?

I check two places: side of oil pan and oil filter. I think the filter is downstream of the cooler so it will run a little lower than the pan. Oil temp at your load will run a little higher than coolant as the pistons have oil cooling jets aimed at the bottom.

I'd figure at your loading, with coolant at 175F, pan temp will be about 185 and filter 180. Somewhere around that.

Ski in NC said:

I check two places: side of oil pan and oil filter. I think the filter is downstream of the cooler so it will run a little lower than the pan. Oil temp at your load will run a little higher than coolant as the pistons have oil cooling jets aimed at the bottom.

I'd figure at your loading, with coolant at 175F, pan temp will be about 185 and filter 180. Somewhere around that.

Click to expand...

Thanks Ski. I will try to check on the way home today. Coolant temps on my engine always seem to stay locked on 172-174. I think that the temp sensor likely only displays in 2 degree increments because it will bounce back and forth between 172 and 174 and never sees 173.

Under way, the oil pan is a bit of a pain to hit well with the temp gun, the oil filter is easy. I’ll see if I can compare the two today.

Ski in NC said:

I check two places: side of oil pan and oil filter. I think the filter is downstream of the cooler so it will run a little lower than the pan. Oil temp at your load will run a little higher than coolant as the pistons have oil cooling jets aimed at the bottom.

I'd figure at your loading, with coolant at 175F, pan temp will be about 185 and filter 180. Somewhere around that.

Click to expand...

Oil filter temp is 180 degrees. The side of the oil pan is 192 degrees. That is at 28% load.

Dang, I was 7F off on the pan side!!

Ski in NC said:

Dang, I was 7F off on the pan side!!

Click to expand...

Wifey B: Ski needs re calibration.

dhays said:

On our way to our anchorage today I made note of of the loading on our Cummins QSB 5.9L engine. The engine says that it was running at 29% load (36% max rpm). We typically run around 1450 rpm. I probably should check to see what my oil temps are. Any idea where is a good place to check oil temps with a laser temp gun?

Click to expand...

All the Cummins units I have worked on that had oil temp sensors we're in the oil pan. I've done a good bit of load banking and the Cummins always seemed to run hotter than cats. I think it was mainly because of the sensor location. On cats we always have them reading oil temp from the a oil galley.

Ski in NC said:

Dang, I was 7F off on the pan side!!

Click to expand...

I was pretty dang impressed that you pegged it so accurately.

BIG CAT said:

All the Cummins units I have worked on that had oil temp sensors we're in the oil pan. I've done a good bit of load banking and the Cummins always seemed to run hotter than cats. I think it was mainly because of the sensor location. On cats we always have them reading oil temp from the a oil galley.

Click to expand...

I red the temp on the side of the oil pan mid-way between the front and back. It was hotter than I would have thought.

So anyway, my engine oil stays hot even at a low load level. This may lend more support to the idea that the common rail Cummins engines may not suffer harm from long periods at a low load.

dhays said:

So anyway, my engine oil stays hot even at a low load level. This may lend more support to the idea that the common rail Cummins engines may not suffer harm from long periods at a low load.

Click to expand...

Does your engine have a coolant heated/cooled exchanger? As discussed in previous posts these units do a great job in keeping oil temps up at low loads and cold PNW waters. My engines are not common rail and at low loads oil temps are above 185 likely due to these exchangers.

sunchaser said:

Does your engine have a coolant heated/cooled exchanger? As discussed in previous posts these units do a great job in keeping oil temps up at low loads and cold PNW waters. My engines are not common rail and at low loads oil temps are above 185 likely due to these exchangers.

Click to expand...

Good question. I don’t believe so.

BIG CAT said:

All the Cummins units I have worked on that had oil temp sensors we're in the oil pan. I've done a good bit of load banking and the Cummins always seemed to run hotter than cats. I think it was mainly because of the sensor location. On cats we always have them reading oil temp from the a oil galley.

Click to expand...

That's the preferred location for an oil temp sensor, as rare as they are.

Unless I'm mistaken, some Cummins models are among the few that have an oil temp thermostat for the cooler, so your results don't surprise me. Perhaps Ski can comment.

There’s a new coolant out now that has a really high boiling point.
May be a good coolant for Old FL’s w a plugged up water jacket aft.
They say you don’t need to worry about boiling. I guess it just dosn’t boil at any thinkable temperature. I would be tempted to run it w a 230 (or so) degree thermostat .. if available. Never heard of such a thermostat. Should/may eliminate the underloading issue by keeping the lube oil quite warm. May be good for all or most engines. Should burn less fuel.

Also may not be able to do this w/o running higher system pressures that may/would require special hoses that could deal w the higher pressures and temps. Blow head gaskets???

Steve .... comment?

i would be tempted to run it w a 330 (or so) degree thermostat

Click to expand...

330 f ?

Yes Jay

OPPS ....
230 degrees!

Edited the mistake.
Thanks Jay!

Steve DAntonio said:

That's the preferred location for an oil temp sensor, as rare as they are.

Unless I'm mistaken, some Cummins models are among the few that have an oil temp thermostat for the cooler, so your results don't surprise me. Perhaps Ski can comment.

Click to expand...

I don't think there is an oil temp thermostat in the Cummins, but could be wrong. I know a good bit about these engines, but have not been deep into that system.

What I do know is this: The oil cooler is at the discharge of the circ water pump. At light load and during warm up with coolant tstat closed (or just cracked slightly open) the coolant circulates through the engine (and oil cooler) and this actually warms the oil. While in this light load mode, the coolant into the oil cooler is about the same temp as the coolant leaving the cyl head. A few degrees of delta, not much more.

At higher loads, most of the coolant entering the circ pump is from the coolant HX so the coolant temp going into the oil cooler is now a good bit cooler than during light load running. And at high load the piston cooling nozzles put a good bit of heat into the oil, so the added cooling is a benefit.

A nice self-regulating system, really. No need for a thermostat

Ski in NC said:

I don't think there is an oil temp thermostat in the Cummins, but could be wrong. I know a good bit about these engines, but have not been deep into that system.

What I do know is this: The oil cooler is at the discharge of the circ water pump. At light load and during warm up with coolant tstat closed (or just cracked slightly open) the coolant circulates through the engine (and oil cooler) and this actually warms the oil. While in this light load mode, the coolant into the oil cooler is about the same temp as the coolant leaving the cyl head. A few degrees of delta, not much more.

At higher loads, most of the coolant entering the circ pump is from the coolant HX so the coolant temp going into the oil cooler is now a good bit cooler than during light load running. And at high load the piston cooling nozzles put a good bit of heat into the oil, so the added cooling is a benefit.

A nice self-regulating system, really. No need for a thermostat

Click to expand...

Thanks for the detailed description of how this system works, I was unfamiliar with that routing.

While I have not held one in my hand, a Cummins rep told me at some point that some Cummins engines have oil coolers, but I could not tell you which models. A quick Google search yielded this Cummins part https://highwayandheavyparts.com/i-...83CQG6WRMYjXkXSivyn1YZgvn60gKtQRoCHfwQAvD_BwE Says it's 215F, which sounds right.

Perhaps it's a result of the routing you described, or an oil cooler t-stat, but I find Cummins engines tend to not exhibit unusually low oil temp once warmed up, usually above 180F.

Nomad Willy said:

There’s a new coolant out now that has a really high boiling point.
May be a good coolant for Old FL’s w a plugged up water jacket aft.
They say you don’t need to worry about boiling. I guess it just dosn’t boil at any thinkable temperature. I would be tempted to run it w a 230 (or so) degree thermostat .. if available. Never heard of such a thermostat. Should/may eliminate the underloading issue by keeping the lube oil quite warm. May be good for all or most engines. Should burn less fuel.

Also may not be able to do this w/o running higher system pressures that may/would require special hoses that could deal w the higher pressures and temps. Blow head gaskets???

Steve .... comment?

Click to expand...

Norm:

I believe you are referring to "waterless" coolant. If so this is the most popular brand https://www.evanscoolant.com/ I own a classic car and if you want to ignite an online firestorm mention this in one of those forums, it's controversial to say the least. I don't use it.

If your cooling system is in good condition, and you replace the coolant every two years (or at the very least have it analyzed), the elevated boiling point established by conventional coolant, and a pressurized cooling system (that pressure raises the boiling point three degrees for every pound of pressure, as well as decreasing cavitation erosion) provide all the cooling and corrosion and boil protection you need. Some engine manufacturers recommend the periodic addition of a coolant supplement that further decreases cavitation (my International 7.3l Ford diesel calls for this) erosion, particularity for wet liner engines. Part of your cooling system service should include regular inspections of the pressure cap, remove it when cold and inspect the rubber gaskets, there should be two for systems that use a recovery bottle, as well as the check valve. More on that subject in this photo essay https://stevedmarineconsulting.com/photo-essay-may-2015/

On the subject of cooling systems, here's a brief column on he subject of coolant recovery bottles, how they work and their importance as a troubleshooting tool https://stevedmarineconsulting.com/the-benefits-of-coolant-recovery-bottles/

Where coolant is concerned, I strongly recommend using the latest recommendation from the engine manufacturer. Today there are a wide range of coolant types, using the wrong one can create costly issues.

Thanks Steve,
I’m not that high tech. My “tech” for coolant is to use orange newer stuff for engine systems that have aluminum that comes in contact w the coolant and old school green for all else. My trawler has green.

I posted the “waterless” info mostly for higher up gearheads than me here on TF but all this kind of mechanical “lore” is usually very interesting to me. In the old days I had a big old Buick with a carb and thought to modify the cooling system eliminating all the hoses and sub pipe to create a system that would run at 250+ degrees. Re-jet the carb (lean) and get Toyota mileage w a Buick V8. Had another Buick 350 that ran on propane.
Many elements of a super hot cooling system like gaskets and things running hotter than designed for may cause problems. Could be unsafe as well. How much heat and pressure will a heater core take .. or a trans oil cooler ect? Just thoughts.