Engine Pre-Lube kit

[Neziak]

I'm thinking of installing a pre-lube kit for my low hours Yanmar 4JH3-HTE. I have read that most of the wear on the engine is from the first 10 or so seconds after engine start - before the oil pressure builds and oil starts to flow.

I have found a few online:

AutoEngineLube Pre Lube System Reduces Engine Wear Up To 60%
https://www.cpperformance.com/produc...e-pre-lube.htm

Are there any others I should consider and has anybody had any experience fitting one to the above engine? Is it a simple job and have there been any problems afterwards?

[model 10]

Of the 2 you listed, the one with the pump could be plumbed to change the oil using that pump. The other kit with just the accumulator is much more simple and will have fewer leaks in the long run.
You don't usually see this stuff on regular engines. Racing engines and really large radial aircraft engines are an examples that do.

[Dockhead]

Are you solving a problem which doesn't exist? Do yacht engines fail because of worn out bearings?

In my experience, they fail much more from lack of use, rusting out, sea water backing up through the exhaust system, overheating. In fact I'm not sure I ever heard of a yacht engine which needed a rebuild because of bearings.

You'll be adding a bunch of plumbing in the crucial pressure side of the lube system. If any part of it ever fails, then you WILL have failed bearings.


I do understand why you want to do this, however. I also have a 4JH3 HTE and absolutely HATE to start it up after an oil change, and hear it rattle for those seconds. I tried cranking it with the stop solenoid closed, but just blew breakers. I thought about it for a long time and finally decided not to mess with it.

[Smokeys Kitchen]

Our stop solenoid failed and we had it replaced with a mechanical pull fuel shutoff. Now we just crank the starter a couple of times for @ 5 seconds with the fuel shutoff pulled out and then push it in and then start the engine.

[a64pilot]

Pre lubers were all the rage back in the 70's. Logically you would think they would prevent a lot of wear, however they don't. My belief is the myth of most engine wear occurs in the first ten seconds etc is just that.

The other thing is only very rarely does bottom end wear trip an overhaul, it's almost always worn cylinders and rings, something a pre luber won't help.

Big ole aircraft Radial engines are a different animal, pretty much one bearing for say a 9 or larger cylinder engine.

[a64pilot]

Turning one over without fuel doesn't really pre lube well, reason is you still have high compression which loads the bearings.
However if you have decompression levers, then if the engine has sat a long time, it might not be a bad idea to turn her over with no compression until it gets oil pressure.

[Maine Sail]

Originally Posted by Neziak

I'm thinking of installing a pre-lube kit for my low hours Yanmar 4JH3-HTE. I have read that most of the wear on the engine is from the first 10 or so seconds after engine start - before the oil pressure builds and oil starts to flow.

I have found a few online:

AutoEngineLube Pre Lube System Reduces Engine Wear Up To 60%
https://www.cpperformance.com/produc...e-pre-lube.htm

Are there any others I should consider and has anybody had any experience fitting one to the above engine? Is it a simple job and have there been any problems afterwards?

The guy who my daughter takes archery lessons from is an owner/operator long haul trucker. His current Cat engine has 1.6 million miles and has not been rebuilt nor even re-sleeved. He runs Shell Rotella and now has an Espar bunk heater (many states no longer allow idling) so he does do many cold starts.. He does not run a pre-lube system yet has manged to rack up 1.6 million miles since he bought this rig...

[Pauls]

There are a couple who have cruised for decdades on a 40'er that used to post regularly on the Dashew's site. They had a homebuilt version of this kit and recommended it highly. They had over 8000 hours on their diesel at the time.

I see pre-lubing as being especially valuable if you run a turbo'd engine. Turbos do fail due to bearing failure, they spin at high rpms, and they are typically the last bearings in the engine to see oil pressure due to their remote location.

[CSY Man]

Originally Posted by Maine Sail

The guy who my daughter takes archery lessons from is an owner/operator long haul trucker. His current Cat engine has 1.6 million miles and has not been rebuilt nor even re-sleeved. He runs Shell Rotella and now has an Espar bunk heater (many states no longer allow idling) so he does do many cold starts.. He does not run a pre-lube system yet has manged to rack up 1.6 million miles since he bought this rig...

1,6 million miles?
At average 50 mph that is 32,000 hours...

The most I have heard of in a boat was a CSY 37, 4-108 with 15,000 hours.
Engine ran well but owner had it overhauled anyways.

Installed an electric pre-luber in a rare car I bought brand new in 1992.
Wanted it to last forever, babied it, never allowed outside in the rain, etc.
Got back into sailboats in 1998 and had no more time to play with the car, sold it to a neighbor who trashed it slowly but surely.
Preluber was a cool novelty but in the long run it surved no useful purpose.

[model 10]

Turbo's need fresh oil during shut down not during a start. The bearing/bushing in the hot section will coke up some oils after shut down. I would think a sailboat turbo is in a pretty good situation with the low power used at the end of a trip. The turbine gets a chance to cool down a little.

[Sailmonkey]

I would never add the prelube complication to a small engine.

As dockhead said, sailboat engines die from lack of use, not cold starts.

Ship engines use pre-libe systems, but they're very different beasts than a little tractor engine.

[Diesel Bill]

All the large medium and low speed diesels I worked on had prelube pumps. That said I've never seen one on smaller over the road or typical sail boat size engines. I admit when I bought my diesel pickup 20 years or so ago, I thought about installing one. Glad now that I didn't bother. I don't think it would hurt, but at the same time don't think it would help all that much on a small engine. I like the idea of an accumulator for turbo engines but if you allow a proper cool down for a few mins. or just reduce load for 5 mins the turbo bearing will live a long life. As guy said a hot turbo shut down will coke up the bearing and then it's all over.

[a64pilot]

Aren't a lot of the newer turbos center section water cooled?
I know my Duramax was.
However as has been said the normal operation of a sailboat is pretty close to ideal for a turbo, I know my motor is at low power or very close to idle for 5 min prior to shutdown dropping anchor or maneuvering through the marina and tieing up to the dock etc.
I'm NA no turbo, but we all operate the same I believe

[CSY Man]

. Turbo's need fresh oil during shut down not during a start

The pre-luber in my car was designed with turbos in mind, it kept pressurizing the oil system after engine shut down for a few minutes.
My car was a non turbo, hence I turned that function off after a while.
Car had 26k miles when I sold it, never had a problem with the pre-luber system, but if one hose had come loose, the oil would disappear in seconds.

[Lepke]

I used prelubers in racing engines. All you really need is a hydraulic accumulator and a valve. I don't think they make a difference.
Before gas and diesel, we had steam engines with lead bearings. They had drip or manual lubrication. All you need is a oil film, not necessarily pressure at starting. Older diesels and old Detroits often had 15 psi or lower at idle.
"Lead" bearings of today are alloys that have much better wear resistant properties.
Concentrating on having clean oil would make a bigger difference.