Prelube setup

I have a Lehman sp135. I would like to plumb my Reverso oil drain/fill pump such that I can use it as a pre-start lube pump.
Is this a good idea?
Has anyone done it?
If so could you please explain or diagram the plumbing.
Thank you in advance.

I have seen a product for that purpose, so you might investigate that. I considered installing that on my last boat's 892s, but was persuaded it is more trouble than it is worth. I also considered having it installed when my current boat was commissioned, but was again persuaded that it isn't worth the cost or complexity, particularly for two reasons: 1) the engines are QSM 11's, which are electronically controlled and turn over 4 revolutions before ignition -- supposedly that is enough to produce oil flow/pressure before the loads of a running engine can do any damage to bearings, and 2) the way I use my boat, once the engines are started, I keep them running at least for hours, often for days, so the startup is relatively inconsequential.

The theory that prelube extends engine life is predicated on the assumption that a lot of bearing wear occurs at startup. I don't know the empirical evidence for that but do note that some high-end cars with expensive engines shut down the engine when idled (at a red light for example) more than a few seconds, and start right up when the accelerator is pressed. If the startup was causing lots of wear, I would think that those cars, especially if used primarily for city driving, would have drastically shortened engine life expectancy.

petdoc4u said:

I have a Lehman sp135. I would like to plumb my Reverso oil drain/fill pump such that I can use it as a pre-start lube pump.
Is this a good idea?
Has anyone done it?
If so could you please explain or diagram the plumbing.
Thank you in advance.

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The question I raise is why? If you think your engine needs pre lube which I doubt You can turn it over a little without a start with a kill switch or whatever(but not too much don't want to pour water into engine from exhaust SX). From what I have read about modern oil and its adhesion to parts very few engines would need pre lube if used at even moderate use intervals. Also I doubt that there are many engines in recreational use that die from old age and a lack of pre-lubing even though on a theoretical basis that instant start may be of greater wear potential. But if you really need a winter project go for it.

In as much as I already have the reverso I thought that it wouldent be too complicated or difficult to run a loop to provide for prelube.
Sounds like perhaps it would have little benefit and therefore not worth the effort.
I appreciate your input- thanks

Can a rubber veined impeller develop enough pressure to do any good?

The pre-oilers I am familiar with use steel gears, It takes a good amount of pressure as well as volume to get oil into the bearings.

KISS, good oil and change it, use the boat and your engine will be happy. Don't add a point of failure that Murphy can exploit some dark and stormy night.


I would think that tapping into the oil cooler would be a good place to start. You do need a bunch of volume to do any good so use a large enough pump and I would add valves to isolate if needed at some point.


Or you could add a pressure chamber to be pressurized with the engine oil pump that holds that oil until you start up then pushes it back into the engine for a pre-lube.
http://www.accusump.com/

Crank and bearings stay wet with oil for weeks after shutdown. Enough to build up an oil film in the same manner as if bearing was prelubed. Film builds up in less than half a rev.

I've taken a bunch of engines apart and almost never seen worn bearings.

And I've seen a backyard style prelube device on a Cat have a fitting fail, it dumped the sump and toasted the engine. He took the devices off when he put in the new engine.

I like prelubing engines that have sat for years, but not the ones that have sat for a few months.

Thanks for the eye-opening comments. I guess I'll move on to my next project.

MYTraveler said:

but do note that some high-end cars with expensive engines shut down the engine when idled (at a red light for example) more than a few seconds, and start right up when the accelerator is pressed.

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This is becoming very common in Europe on all types of vehicles from cheap to expensive. Every vehicle we've rented in the UK and France over the last few years has had this feature. On the cars and minivans we've had it was a selectable feature; it can be turned on or off at will via a menu.

I have a pre lube pump on my Perkins T6354. The lines leaked a lot so I had new ones made and changed them last winter. It was a hell of a job getting to the fitting that attaches where the drain plug used to be. It had a quick disconnect that leaked so I piped it into a mini manifold so that I could hopefully use it for an oil change pump. Well, oil change time cam in November and all it did was spit small amounts of oil. Now I read in this thread that I don't really need it?

My boat had prelubers on both CATS when I bought it. One pump failed and the replacement pump was $2,500. They are high pressure pumps. I knew if I replaced it, the second pump wasn't far behind. I spoke to my Cat mechanic and he said there was no need for them. I removed both.

The electric backed Accusump is probably the simplest system.

Canton Racing Products

I can't imagine why you'd need a high pressure pump to pre-oil.

I have read elsewhere, and I think someone here not too long ago posted that the cheapest preluber was a pressure storage tank that you filled with pressurized oil after the engine started and came up to pressure, shut the valve until prestart the next start.

Not sure how it would work with cold oil or how to plumb it so that it actually works and gets oil to the most critical parts.....

Years ago I had read articles about prelubers and after gaining years of experience decided that for the run of the mill recreational motor owner....not really required.

Yea, the pressure tank and solenoid valve system is probably the simplest and most reliable. If one is that motivated to do it.

I crank the old FL a little while holding down the stop button. There.... It is pre lubed.

Old deckhand said:

I crank the old FL a little while holding down the stop button. There.... It is pre lubed.

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Not exactly.

psneeld said:

I have read elsewhere, and I think someone here not too long ago posted that the cheapest preluber was a pressure storage tank that you filled with pressurized oil after the engine started and came up to pressure, shut the valve until prestart the next start.

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That would be an Accusump.

Old deckhand said:

I crank the old FL a little while holding down the stop button. There.... It is pre lubed.

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After a few seconds of turning the engine over holding the stop button down I note the oil pressure rise according to the oil pressure gauge. Probably not perfect pre lube but better then just starting the engine without using this method.

Super simple. A small accumulator tank, one solinoid valve, key switch controlled. Even the folks on trawler forum (caveman) can do it.

Capt.Bill11 said:

Not exactly.

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Why not Bill?

Pre lubing wont get to pistons and cylinders. Getting to cam followers is questionable.


IIRC the Cummins manual recommended spinning with fuel off to get oil pressure up for long storage dry starts.

bayview said:

Why not Bill?

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Because the point of pre-lubing is to have oil AND oil under pressure flowing before the engine ever turns over.

It's always been my understanding that oil under pressure is being forced in between the bearing and what ever is "riding" on it. So that the two surfaces never really come into contact with each other.

That is why the claim is made that most of the wear happens at start up when there is no oil under pressure being injected between the two surfaces. So the surfaces are in contact, or perhaps more in contact than normal, with each other till the pressure builds.

At least that is the theory as I've seen it presented in the past.

I don't know about you guys but in most cases when I've been rolling over an engine that is not starting up right away, I can tell when the oil pressure has built up by how much easier it starts to turn over after the pressure comes up.

That said, I'm not telling the OP to run out and set his oil change pump up as a pre-oiler.

For a long running fairly bulletproof engine like a Lehman, they probably would be of little or no benefit.

The accusump that I mentioned in post 5 is a good way to go if you feel that a prelube would help prolong your engine.

High pressure is relative but 60-80 PSI of cold oil would require a bit more then a rubber impeller pump. Some engines have even higher oil pressure when running, pre-lube requires a bit more then the "limbering up" of cranking for a few seconds without starting.

You want real oil pressure for a bit, how high does your oil pressure gauge read when cranking?

Bill in the above post you make a good argument as to why you really want a high pressure pump as a preoiler.

I agree this is not really going to do much most of us, I you had an emergency response engine that was going to be started cold and ran hard right at startup perhaps it might make somewhat of a difference. You just don't see many run-out FL120

IIRC oil routing is not simpe. Cranks have passages that pick up oil as it turns not simply flowing around between the bearing and crank. cam followers are a dry start concern and each engine probably lubes those differently. Cold heavy oil isn't likely to flow through narrow clearances very well. Cylenders are not lubed by pressure. All in all I think the effort not worth it. Some engine makers give dry start procedures to be used after long storage. Blocking air intake should decrease compression loads and make fuel off spinning easier and with less bearing load.


AL that being said I can only remember one engine failing from bearings and that was after the owner ignored low oil pressure on a many thousand hour engine and made the trip to Venezuela from FL and used the boat there for several years. Spun bearings are not unheard of after a rebuild but general failure is rare.


Brings to mind an answer to some questions from old diesel commercial operators.


How do you store the engines Capt? "turn them off"
How do you start up your stored engines Capt? "start them up"

IMO only we boaters obsess over our engines. Diesels are used in equipment round the world where thy are just shut down and started up after any period of storage.


I wonder if any ex military guys know what Govt procedures are?

bayview said:

I wonder if any ex military guys know what Govt procedures are?

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Jump in, hit the starter, put in gear and drive it like ya just stole it.

Ex-USAF Firefighter back in the SAC days

All we knew about pre-lube, it called foreplay as I recall

I think an oil pan heater that kept the oil in the sump around 120F would be simpler and more beneficial reducing wear. Especially if the engine is used at least monthly. Read www. "bobstheoilguy.com".
In the nuclear power industry, we had both pre-lube pumps and oil heaters to keep straight 40 weight oil >110F. Both were a constant source of maintenance headaches. The reason was the requirement to start the engine from 0 to rated rpm in <10 seconds and accept full load (4443 Kw) in <130 seconds without damage. Try that with a cold diesel!

High Wire said:

I think an oil pan heater that kept the oil in the sump around 120F would be simpler and more beneficial reducing wear. Especially if the engine is used at least monthly. Read www. "bobstheoilguy.com".
In the nuclear power industry, we had both pre-lube pumps and oil heaters to keep straight 40 weight oil >110F. Both were a constant source of maintenance headaches. The reason was the requirement to start the engine from 0 to rated rpm in <10 seconds and accept full load (4443 Kw) in <130 seconds without damage. Try that with a cold diesel!

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...I think that is all the USCG does....at least into the 90's with the older boats.

Haven't heard anyone discuss pre-lubers but my circle of info has all but withered for everything but SAR.

Large industrial and marine engines have coolant heating and prelube pumps. Coolant heating to control corrosion and keep oil viscosity down. Prelube probably traditional, but lube circuit might take a LOT of time to fill compared to our little engines.

I like the idea of prelube, but not enough to put on my own engines.

system using a Reverso pump

This is the one I purchased - not installed yet, so I don't know how well it works. There is a link to an installation drawing. The pumps are from Reverso. Either connect the oil pressure switch and have the back-up function or just install the on/off switch and use it as pre-oiler only:

Pre-Oiler and Back-Up Engine Oil Pump | INFINITY Aerospace

I recall 110-115 revolutions on a hand driven gear pump to prelube a Fairbanks Morse ND81/8 prior to snorkeling. Have lift pumps on some giant AC motors (>20,000 Hp) and refiners with journal bearings at a mill I worked in. No need to have on my truck or boat. One of those things that are a great idea, but probably less so in actual practice.