Starting an engine after a year ashore - low cranking speed

[Heckler]

An interesting theory and not something I have ever observed so strongly with petrol engines but I can well understand that diesel engines will behave differently and that to run freely the bore does need some diesel lubrication until the engine starts and splash lubrication from the sump can take effect. The only thing which suggests another issue is that you observed plenty of fuel at the injectors so I would have expected sufficient bore lubrication but, as you say, if it works, it works.

Richard

The diesel injection doesnt and isnt intended to lubricate the bores. The vast majority of plain shell bearing engines have a drilling up the conrod which exits about halfway up where the pressurised oil from the big ends sprays out to cool the underside of the pistons and to lubricate the piston rings and bore. You will see behind the piston rings, holes that allow this. You will see in the shell bearings a hole in one of them that allows access to the conrod oil drilling from the big end oil supply. In some cases, like my MD22, there are little pipes that are connected to the main crank case oil gallery by banjo bolts that are open ended and point in to the bores and do the same job.
Stu

 

[RichardS]

The diesel injection doesnt and isnt intended to lubricate the bores. The vast majority of plain shell bearing engines have a drilling up the conrod which exits about halfway up where the pressurised oil from the big ends sprays out to cool the underside of the pistons and to lubricate the piston rings and bore. You will see behind the piston rings, holes that allow this. You will see in the shell bearings a hole in one of them that allows access to the conrod oil drilling from the big end oil supply. In some cases, like my MD22, there are little pipes that are connected to the main crank case oil gallery by banjo bolts that are open ended and point in to the bores and do the same job.
Stu

I'm not sure why you're quoting me Stu as it's the OP's theory rather than mine.

Richard

 

[VMALLOWS]

kacecar,
A really interesting conclusion to the problem - thanks for sharing. I can well see that the lift-pump might have failed during the long lay up, but I certainly would not have considered it with your symptoms. Maybe we should all remember to try the old trick of using a simple gravity feed when all else seems to fail. I wonder whether the old petrol-engine trick of a few drops of oil into the cylinders would have got the cranking speed up and helped with the diagnosis ...maybe even kicking the lift pump into operation?

Even my slow cranking starter turned out to be not quite what I expected ..... the end bush had worn to an elliptical shape resulting in the rotor running off-centre, although that in turn had made a mess of the brushes. A 65p fix, but a pain putting it back together while I waited for the bearing and then dismantling again.

 

[Heckler]

I'm not sure why you're quoting me Stu as it's the OP's theory rather than mine.

Richard

"I can well understand that diesel engines will behave differently and that to run freely the bore does need some diesel lubrication until the engine starts and splash lubrication from the sump can take effect."
Your words, stop digging!
Stu

 

[PaulRainbow]

I'm not sure why you're quoting me Stu as it's the OP's theory rather than mine.

Richard

Bollox !!

You said

I can well understand that diesel engines will behave differently and that to run freely the bore does need some diesel lubrication until the engine starts and splash lubrication from the sump can take effect.

 

[pcatterall]

read it all with interest especially as a mate cannot get his van to start after suffering flooding last year. The water did not come above sump level and there is no water in the sump.
The engine would not turn over quickly like the OPs, he tried new batteries and an exchange starter motor.
Following this thread I will advise him to check the voltage drop, ensure there is no water in the exhaust etc.
The pump fault intrigued me, especially the comment that the engine turned over faster when the pump was replaced, could there be some mechanical resistance in the pump that was slowing the turn over?

 

[Heckler]

Bollox !!

You said

Hee hee!
Stu

 

[RichardS]

"I can well understand that diesel engines will behave differently and that to run freely the bore does need some diesel lubrication until the engine starts and splash lubrication from the sump can take effect."
Your words, stop digging!
Stu

Bollox !!

You said

Hee hee!
Stu

I sometimes worry about the standards of basic English comprehension on this forum.

The OP said "Perhaps the presence of raw diesel in the cylinder is necessary/useful as a lubricant" a good 9 hours before I replied "An interesting theory ......."

Now, if that doesn't make it the OP's theory rather than mine, then I'm a fiddler's bitch.

Put away those spades guys .... your hands must be red raw! :encouragement:

Richard

 

[QBhoy]

All arguing aside...the diesel sure ain't intended to provide any lubrication...except perhaps to the fuel pump.
If you are getting strong pulses of fuel while bleeding the injectors at cranking, I'd suggest the fuel pump is ok too.
Best answer is to perhaps get a good big battery, open the compression up and turn over until you have a fair oil pressure evident. Close the compression and turn her over until she fires. Easy start isn't a bad idea.

 

[macd]

Best answer is to perhaps get a good big battery, open the compression up and turn over until you have a fair oil pressure evident. Close the compression and turn her over until she fires. Easy start isn't a bad idea.

Unless that's general advice to anyone else who experiences problems with "Starting an engine after a year ashore - low cranking speed", it's a tad redundant in this case.

Perhaps you haven't read post #19?

 

[macd]

I sometimes worry about the standards of basic English comprehension on this forum.

Wrong again, Richard. The word is "frequently".

Manifestly, the OP raised the notion of piston lubrication by fuel; you commented on it.