OM617 fresh from the machine shop problems!! - Page 3 - PeachParts Mercedes-Benz Forum

jay_bob · #31 03-01-2016, 01:32 PM

For Leathermang:

Dieselmeken AB is an injector pump shop in Sweden. The man who runs it is named Goran Lundgren. He is a legend over on superturbodiesel.com forum.

He is an expert on Bosch (and many other) pumps and can work magic with them. Never met him and no affiliation but I have watched his videos.

Go on YouTube and search for dieselmeken.

leathermang · #32 03-01-2016, 04:55 PM

Quote:

Originally Posted by Garage Yourself

I have just had a machinist come to measure the bore with calibrated tools and the results are different than my measurement.

The cylinder true diameter is 91.008 mm and round.

Measuring the bore correctly is not an easy job...and except that you have new sleeves can not be done correctly with the pistons in the bore..... some tools requires ' touch' learned from experience . ( referring to telescoping gauges and then transferring the measurement from them )....
Ok... so you now have a bore measurement you trust..
but you did not measure your pistons before installing them ?
Or before the bores were honed to size ?
There are questions in this thread which you have not answered....

leathermang · #33 03-01-2016, 05:26 PM

Quote:

Originally Posted by Garage Yourself

I have just had a machinist come to measure the bore with calibrated tools and the results are different than my measurement.
The cylinder true diameter is 91.008 mm and round.

Ok... so according to my reading.... your bore is .080 mm larger than the largest cylinder bore allowed for the group 2 piston group. ( the largest group )....

Piston clearance when new should be 0.043 -- wear limit 0.12

Did you say which ' piston group' the cleaned piston you installed was ?

Based on your incorrect initial measurement of 90.920mm - 90.925mm I assume you have the group 2 piston installed ?

leathermang · #34 03-02-2016, 11:09 PM

LOL..... it is not your thread.... it is the forum's....
and I have been saying exactly the mechanical truth based on the FSM....
which you assumed you did not need to consult before you acted.
If you are embarrassed by the truthful statements I have posted you are free to select my screen name and hit the ' ignore ' button... and you will not see what I post...
But everyone else understands where you failed.... and why you are acting like a child caught with his hand in the cookie jar. Another member just PM'd me and mentioned that you may even be liable to your student for the damage done by not following the factory instructions... (?). Morally you clearly are... which may be different from legally....

leathermang · #35 03-02-2016, 11:39 PM

Quote:

Originally Posted by Garage Yourself

..... but have easily over a hundred high output gasoline builds giving their odometers work outs. ....

But admit that you did not accurately measure the bore on the engine in question...
Are gasser bores so different in terms of measuring them that those hundred engines did not provide expertise when it came to this engine ?

leathermang · #36 03-03-2016, 12:28 AM

I know enough to make sure I give the machine shop the relevant information.
Which I get from the book written by the people who designed and manufactured the engine in question.
Those people have spent millions and millions of dollars on Research and Development.
They are also in the legit feedback loop from problems encountered in the real world through their dealers.
For you to denigrate the information in the Factory Shop Manual while in the process of redoing that engine due to not following the Factory Shop Manual .... everyone except you can see that that is illogical.
Can't find the ' ignore button' heh..? LOL

mach4 · #37 03-03-2016, 01:07 AM

Quote:

Originally Posted by leathermang

Can't find the ' ignore button' heh..? LOL

I found it!

Stretch · #38 03-03-2016, 03:22 AM

Wow as usual some of these threads get long pretty quickly.

I'll try and help by starting at the beginning =>

Quote:

Originally Posted by Garage Yourself

We have an 85 300TD, fresh oem sleeves, fresh rings and cleaned pistons. Cylinder bore measures 90.920mm - 90.925mm and are round. The engine has aprox 400 miles, but the rings simply wouldn't seat, crank case pressure/blow was excessive. So we opened her up and found this

Engine has not been overheated and has not yet seen anymore than 5 psi of boost.
The rings end gaps were with in spec.
Fuel pump timing is at 20 deg (As per Dieselmeken's specs, running his M pump)

What can cause this?? All 5 cylinders have the same wear in the same spot.

Thank you, can't wait to get this girl movin!!

Attachment 135050

Attachment 135051

My initial reaction is to check the crankshaft end float.

I would then check each piston height with the top of the block (this is going to involve finding TDC which might cause some feathers to get flustered <= warning!) - I'm thinking along the lines of bent connecting rods...

mike-81-240d · #39 03-03-2016, 08:55 AM

Well that escalated quickly.

Garage Yourself · #40 03-03-2016, 09:25 AM

Thank you for bringing it back on topic. The head and block were both skimmed and we will be measuring "The Poke" today before we break her down.

Are there options for head gasket thickness? If there are is there a chart or specs for selecting the proper one?

BillGrissom · #41 03-03-2016, 11:41 AM

Coming in late. I don't see how the thrust bearings would explain the wear on the sides of the cylinders. The connecting rod is free to pivot in that direction, as is the piston. I would think that mis-aligning the crankshaft axially (wrong thrust bearings) would cause wear on the fwd or aft sides of the cylinder sleeves. Best guess might be that the ring end gaps are not sufficient, causing binding. If correct, perhaps the block over-heated so the thermal expansion was too much for the gaps. Not an expert, I have only re-ringed gas engines, but I started rebuilding an OM617 (installed new sleeves), so very interested in your unfortunate experience.

Some members here can come across as too persistant, as one might expect from M-B owners, but they do sometimes contribute helpful ideas. I recommend applying a filter to all posts and just ignore posts that seem condescending and unhelpful.

barry12345 · #42 03-03-2016, 11:55 AM

Quote:

Originally Posted by Garage Yourself

Thank you for bringing it back on topic. The head and block were both skimmed and we will be measuring "The Poke" today before we break her down.

Are there options for head gasket thickness? If there are is there a chart or specs for selecting the proper one?

You have to know how much material was removed from the head and block. There is only one over thick head gasket size to the best of my limited knowledge.
]
You are not allowed much off the head as you pretty well know I assume.

Stretch · #43 03-03-2016, 12:59 PM

Quote:

Originally Posted by Garage Yourself

Thank you for bringing it back on topic. The head and block were both skimmed and we will be measuring "The Poke" today before we break her down.

Are there options for head gasket thickness? If there are is there a chart or specs for selecting the proper one?

Quote:

Originally Posted by barry12345

You have to know how much material was removed from the head and block. There is only one over thick head gasket size to the best of my limited knowledge.
]
You are not allowed much off the head as you pretty well know I assume.

To the best of my knowledge there isn't an extra thick "stock" head gasket - I think if you needed one you'd have to get a custom made solution.

The head can actually be skimmed quite a bit so long as you recess the valve seats. There's a specification for longitudinal flatness and the depth of the valve seats from the head surface.

Quote:

Originally Posted by BillGrissom

Coming in late. I don't see how the thrust bearings would explain the wear on the sides of the cylinders. The connecting rod is free to pivot in that direction, as is the piston. I would think that mis-aligning the crankshaft axially (wrong thrust bearings) would cause wear on the fwd or aft sides of the cylinder sleeves...

That's where the wear is isn't it? Fore and aft?

If you're getting shiny patches or shadows on the lateral sides of the cylinder bores say on the "thrust side" then there's too much wear in the rings/ bores.

mike-81-240d · #44 03-03-2016, 04:31 PM

I know someone on std years ago had a custom copper cometic gasket made for his 300sd.

83TD · #45 03-03-2016, 06:20 PM

If head is skimmed, pre chamber seals also have to be checked for clearance and replaced with thicker ones if necessary. Not sure if piston could contact pre chamber if not done.