MEP-803 fuel pump Length discrepancy

[Sidis8]

The saga continues.
Took apart the oil pressure regulator, looks decent. Only thing is I swear I read in another post on here there’s supposed to be some kind of steel ball that’s in here ? Not seeing one, also the spring looks deformed on one end ? Is this normal ?

 

[loosegravel]

The saga continues.
Took apart the oil pressure regulator, looks decent. Only thing is I swear I read in another post on here there’s supposed to be some kind of steel ball that’s in here ? Not seeing one, also the spring looks deformed on one end ? Is this normal ?

That looks correct. It’s a steel plunger rather than a steel ball. I’m not sure about the spring though. Ray will comment on that tomorrow. So, are you still dealing with low compression issues?

 

[Sidis8]

That looks correct. It’s a steel plunger rather than a steel ball. I’m not sure about the spring though. Ray will comment on that tomorrow. So, are you still dealing with low compression issues?

compressions all good.

going to do a leak down test tonight just as extra insurance.

 

[Sidis8]

So got home from work and made the adapter for a leak down test. All 4 cylinders at tdc compression failed, can clearly hear air escaping from the oil fill port on each. Guess the rings are shot

I guess it’s rebuild time. Can anyone recommend a good kit to get ???

 

[Mullaney]

So got home from work and made the adapter for a leak down test. All 4 cylinders at tdc compression failed, can clearly hear air escaping from the oil fill port on each. Guess the rings are shot

I guess it’s rebuild time. Can anyone recommend a good kit to get ???

.
Before you "throw in the towel" what about pumping some Marvel Mystery Oil on top of the rings and let it sit for a few days. That might free up the rings - if the cylinders are't already "toasted" from all the cranking. Maybe. It has worked before in days gone by.

.

 

[Guyfang]

Pull the pistons and see if the rings are stuck, before you start buying parts. Or, better yet, read and heed Tim's post above mine, THEN if nothing gets better, read mine again.

 

[Sidis8]

I tried the mystery oil, it would help but but then the next day back to square one.

just pulled piston number 2, the cylinder bore has a few rust spots, and I’ll post a pic of the cylinder.

The cylinder leak down was the final nail in the coffin for me, especially listening to the air escape out the bottom of the pistons

Am I right to assume the discoloration on the bottom of the piston was due to lack of regular oil changes ?

what do you guys think ?

 

[loosegravel]

I tried the mystery oil, it would help but but then the next day back to square one.

just pulled piston number 2, the cylinder bore has a few rust spots, and I’ll post a pic of the cylinder.

The cylinder leak down was the final nail in the coffin for me, especially listening to the air escape out the bottom of the pistons

Am I right to assume the discoloration on the bottom of the piston was due to lack of regular oil changes ?

what do you guys think ?

I’ve seen this on a couple of units that I had. One was so bad I had to replace (3) pistons. The rings had seized and the piston skirts were rubbing off on the cylinder walls. I don’t think oil changes or lack there of has anything to do with the discoloration.

 

[loosegravel]

So got home from work and made the adapter for a leak down test. All 4 cylinders at tdc compression failed, can clearly hear air escaping from the oil fill port on each. Guess the rings are shot

I guess it’s rebuild time. Can anyone recommend a good kit to get ???

Some of us have received great parts support from “Sleeman & Hawken” in the UK. They responded very well to my parts needs. I was blown away with the 3 day shipping time. Email seems to work well with them.

 

[Sidis8]

I pulled the pistons and they say

751-42670/0.750/5
And
72
10-10

Are these oversize or stock pistons ? After measuring im leaning to 10 over.

what do you guys think ?

 

[loosegravel]

I’m trying to decipher what your numbers are. They don’t quite match what’s in the manual.

 

[Sidis8]

I’m trying to decipher what your numbers are. They don’t quite match what’s in the manual.View attachment 892870

They didn’t match either when I looked

 

[loosegravel]

They didn’t match either when I looked

Pictures are always good, thanks. The lower numbers are the build date from what I understand. The /0.750 at the end of the upper number is the oversize. If you look at the manual, the oversize's are in mm. So, .25mm is just under .010" oversize, .50mm is .020" oversize and .75mm (not listed on the page I sent you) is .030" oversize. I hope someone like Ray pipes in here if I'm wrong.

 

[Sidis8]

Pictures are always good, thanks. The lower numbers are the build date from what I understand. The /0.750 at the end of the upper number is the oversize. If you look at the manual, the oversize's are in mm. So, .25mm is just under .010" oversize, .50mm is .020" oversize and .75mm (not listed on the page I sent you) is .030" oversize. I hope someone like Ray pipes in here if I'm wrong.

Do you know if they make them bigger ? I’m gonna have to bore out the block to get rid of pitting, especially on cylinder #2.

 

[loosegravel]

Do you know if they make them bigger ? I’m gonna have to bore out the block to get rid of pitting, especially on cylinder #2.

That would be a question for Sleeman & Hawken. Have you had any correspondence with them yet?

 

[Sidis8]

That would be a question for Sleeman & Hawken. Have you had any correspondence with them yet?

yes I did, got a few things coming from them that I couldn’t source locally

 

[loosegravel]

yes I did, got a few things coming from them that I couldn’t source locally

I seem to remember that they go up to 1.0mm oversize. (.040") But I would ask them.

 

[Sidis8]

So after more measuring, I’m getting a 3.412” across the thrust face of the piston. Looking in the manual, standard is supposed to be around 3.384”, then add the .75mm (.029”), gets me to the above number. These are definitely .75mm oversize pistons. my conversions might be a bit off going from mm to inches.

I hope I can source some 1mm oversize as cylinder 2 still needs to get cleaned up to get rid of a pitting spot.

is it normal practice for these engines to get bored out during remanufacturing ? This one must have been ate up for them to go .75mm over right off the bat.

 

[Light in the Dark]

Normally when the engines go through the reman process, L-P (or if it were done by a civilian contractor) would affix a tag to the engine showing the bore change. At least, I've seen it... but like many resets, while they are all supposed to be done to a standard, thats not often the case.

 

[Ray70]

This tag L.I.T.D mentioned is normally on the right side of the block forward of the starter and below the alternator.
Typically shows the new bore, main and rod bearing sizes.