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Old 04-20-2012, 09:12 PM   #81
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Art--- I think you are correct in theory, but in the real world I think that's all it is--- an armchair theory. I have yet to purchase a vehicle with an owners manual that says to turn the engine over on the starter to build oil pressure before I start it. The manuals or instructions covering all the aircraft, marine, and diesel equipment I have run over the years have never mentioned turning the engine on the starter to build pre-start oil pressure.

If it was any sort of a factor you'd think the engine manufacturers would be all over themselves either installing pre-lube systems or telling the owners/operators to make sure to turn the engine over with the starter to extend engine life. They don't.

Leaving an engine sit for long periods of disuse is something else, and pickling or some sort of pre-lube is advisable. But engines that are getting regular use? Starter-based pre-lube is a waste of time in terms of extending the service life of the engine. In theory it will. In reality that engine's gonna crap out for some other reason LONG before the minimal reduction in startup wear is going to make an appreciable difference in the engine's performance.

I have been asking about this sort of thing of professionals--- vehicle, aircraft, equipment, and marine engine people---- for decades because like you, I believed that on paper the theory makes sense. But the ONLY place I have ever seen this practice promoted or defended has been among amateurs like those of us on this forum.

So I'm gonna put my faith in the Yamaha, Cummins, Lugger, Lehman, Pratt & Whitney, Wright, Lycoming, Continental, Land Rover, Ford, and BMW people I've talked to about this over the years (these are the ones I remember--- there have been more) and not bother to "pre-lube" the diesels in our boat (or anything else we operate) simpy by turning it over on the starter. And I'll bet our 39 year old Lehmans are never going to know the difference in the many thousands of hours they have left in them before their first overhaul.
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Old 04-21-2012, 12:16 AM   #82
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Quote:
Originally Posted by Marin View Post

Art--- I think you are correct in theory, but in the real world I think that's all it is--- an armchair theory.

I have been asking about this sort of thing of professionals--- vehicle, aircraft, equipment, and marine engine people---- for decades because like you, I believed that on paper the theory makes sense. But the ONLY place I have ever seen this practice promoted or defended has been among amateurs like those of us on this forum.
Marin

I too have spoken to many excellent mechanics / professional engine rebuilders. I know of what I speak... starter actuated pre-lube by establishing oil pressure before start-up is a good way to extend engine life.

I recomend you visit BEARING FAILURES:
http://www.advantageengineparts.com/...ingfailure.pdf

Following are two quotes: (I highlighted the "primed before start up" sections):

WIPED

Appearance: Bearing surface smeared or scratched and torn. Bearing metal melted and re-solidified along the edges.
Causes: Lubrication system not primed before start-up. Clogged oil passage. Oil pump failure Improper installation (oil hole blocked). Concentrated loading in localized area of bearing. Misalignment of shaft and bearing surfaces. Insufficient clearance.

OIL STARVATION
Appearance: Bearing surface streaked and smeared with worst damage at center. Heat discoloration. May show pick-up of bearing material on shaft depending on severity. NOTE: This condition will progress into “Wiping” and “Hot Short”.
Causes: Low oil level, blocked oil pick-up, oil pump failure, blocked oil hole or oil passage, excessive dilution of oil by fuel or coolant, lubrication system not primed before start-up, overspeed.
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Old 04-21-2012, 01:30 AM   #83
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Sorry, Art. I don't buy it. WAY too many reputable mechanics and engine engineers have told me that pre-lube by starter is a giant waste of time in terms of getting more serviceable life out of an engine. The number of people--- mostly amateurs--- who have endorsed this practice I can count on one hand.

So I'm going with the pros on this one. But crank away if you think it's helping. If you believe hard enough that it will actually make a difference you never know, it just might. Especially if you mount a little pot-bellied Buddha at your helm station and rub its stomach before every engine start. The PT boat guys did this before every mission. So did the aku (albacore tuna) fishermen in Hawaii before they went out every day.

One of the girls in the executive lounge of the hotel we stayed in in Xiamen, China gave me a little wooden Buddha and I rub its tummy every day before going to work. Don't know if it makes any actual difference but it makes me feel like I'm being pro-active in how my day goes. So perhaps one of these little guys will help you believe your engine cranking is doing some good. Never underestimate the power of superstition......

By the way, since you have a pair of gas engines, I have a couple of 100 mpg carburetors I'll be happy to sell you since I've got no use for them anymore. Guy who sold them to me swore they worked great. "You just have to have faith," he said.
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Old 04-21-2012, 02:07 AM   #84
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[QUOTE=Marin;83807]

Sorry, Art. I don't buy it. WAY too many reputable mechanics and engine engineers have told me that pre-lube by starter is a giant waste of time in terms of getting more serviceable life out of an engine. The number of people--- mostly amateurs--- who have endorsed this practice I can count on one hand. I SIMPLY DON'T BUY THOSE STATEMENTS AT ALL.

So I'm going with the pros on this one. But crank away if you think it's helping. If you believe hard enough that it will actually make a difference you never know, it just might. Especially if you mount a little pot-bellied Buddha at your helm station and rub its stomach before every engine start. The PT boat guys did this before every mission. So did the aku (albacore tuna) fishermen in Hawaii before they went out every day. WHEN BEING PROVEN INCORRECT MANY DEBATORS RELY ON MEANINGLESS OFF SUBJECT HUMOR TO TRY AND DIVERT INTEREST FROM A SUBJECT, ESPECIALLY A SUBJECT THEY DESIRE TO HOLD INCORRECT VIEW UPON... NO MATTER THE PROOF DISPLAYED

One of the girls in the executive lounge of the hotel we stayed in in Xiamen, China gave me a little wooden Buddha and I rub its tummy every day before going to work. Don't know if it makes any actual difference but it makes me feel like I'm being pro-active in how my day goes. So perhaps one of these little guys will help you believe your engine cranking is doing some good. Never underestimate the power of superstition...... OH BOY, MORE HUMOR...

By the way, since you have a pair of gas engines, I have a couple of 100 mpg carburetors I'll be happy to sell you since I've got no use for them anymore. Guy who sold them to me swore they worked great. "You just have to have faith," he said. HA HA HA HA HA - AND STILL, STARTER ACTIVATED PRE-LUBE OIL PRESSURE EXTENDS ENGINE BEARING AND OTHER ENGINE PORTIONS' LIFE.

SORRY MARIN, BUT, HUMAR NEVER ALTERS FACTS! CAREFULLY READ THE LINK IN MY PREVIOUS POST.
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Old 04-21-2012, 05:35 AM   #85
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Most ships and other vessels with large engines will use a starting drill of heating the lube oil and then pressurizing the oil galleries.

Weather this drill will extend the service life of a small diesel , that is normally killed , seldom worn out is doubtful, but possible.

Our "solution" an installed 120v block heater ,which might extend engine life , but sure does make starting in the cold far easier.

The difference between 3, 30 second cranks with a wait time , and a smokey start ,,, or a 2 second crank, no smoke.

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Old 04-21-2012, 02:16 PM   #86
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[QUOTE=Art;83808]
Quote:
Originally Posted by Marin View Post

CAREFULLY READ THE LINK IN MY PREVIOUS POST.
I did. They describe conditions that can occur from insufficient lubrication and I have no argument with them. But the wear that occurs from starting an engine normally--- and I don't mean specialized engines or huge engines or engines that have to be able to come to full power immediately, but every day engines like the ones in our cars and boats and the airplane I fly--- is not significant enough to care about. If it was, these engines would have proper pre-lube systems or the manufacturers would all be telling us to turn the engines over with the starter before starting. They don't.

If you want to operate your boat's engines using an armchair theory because you're convinced it makes a difference, for heaven's sake don't stop doing it. You're certainly not hurting anything. The life cycles of a bazillion engines all over the planet have demonstrated that you aren't accomplishing anything meaningful with regards to extending the service life of your engine--- they all crapped out for some other reason other than a bit of scuffing on the the crank bearings from startup---but you aren't hurting anything by doing it.

I'm not trying to change your mind. Only present the commonly held view among professionals that the practice you advocate is totally unnecessary.
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Old 04-21-2012, 02:30 PM   #87
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Nuff Said! On following either accounting... Buyer Be Ware!!
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Old 04-21-2012, 05:01 PM   #88
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My Perkins book Said not to use Syn oil and I am going to stay with that.
Diesel engines are high compression and need to have rings seal to the cylinders.
I use a bypass oil filter and oil analysis. It has worked well for many years.
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Old 04-21-2012, 09:56 PM   #89
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I took a seminar given by Lehman engine 'guru' Norm Dibble. Norm worked for Pat's Marine Engines in Seattle, and before that at Doc Freemans. He is a well respected Lehman mechanic, having worked on FL's for 40 years.

He recommended 'preheating' Lehmans by cranking with the stop lever activated to heat the combustion chamber in cool or cold weather. It must be done with the fuel stop lever activated to prevent any fuel being injected into the cylinders. The compression heats up the combustion chambers AND circulates some lube oil. My experience with this procedure is positive. The 'dry' (no fuel) cranking allows for a much faster start when cold and after a long period of storage in the winter. I also note that the oil pressure builds up faster than with just a regular 'crank till it starts' cold start.

It is critical to not let fuel be injected into the cylinders during preheat, as the injected fuel cools the cylinder defeating the preheating by compression. That fuel also washes the cylinder walls, and adds to the dilution of the oil.

He also recommended using Chevron Delo 400 30 wt. oil in the PNW. His statement was that multigrade oils contain additives so that part of the quart is not actually dino oil.

I respect his 40 years of experience with Lehmans. I follow his recommendations as I do not want to experiment with my own engine.

The cranking procedure recommended is to crank for a count of 10 with the stop button held down. Then while still cranking, release the stop button. The engine should start promptly.
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Old 04-21-2012, 11:05 PM   #90
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I've heard about that method but never had occasion to try it. We use our boat year round, and often more in the late fall, winter, and early spring than in the summer. But we keep heat in the engine room so its always about 50-55 degrees down there when we start the engines. They start instanty just like they do in the warmer parts of the year. We have yet to even have to use the cold start knobs.

But if we didn't keep heat in the engine room I've heard the cold start knobs (connected to the fuel limit bypass arm on the injection pump) are quite effective. And Norm Dibble's method makes sense, too, on an engine with no glow plugs. Our generator has glow plugs as well as a pre-heat coil in the air intake. Boy, do those make a difference when starting the thing cold. Too bad the Ford Dorset (Lehman 120) engine didn't have them fitted at the factory.
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Old 04-22-2012, 06:25 AM   #91
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"His statement was that multigrade oils contain additives so that part of the quart is not actually dino oil."

This is true for ALL oils , as all contain required 10-15% additive packages.

The difference is multi grade has a stiffing agent (think flour in the gravy) that has the oil get thicker when warm.

I agree that one weight is best for old engines , but not because ther is "more oil in the oil".

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