Parts sourcing - Top-End Rebuild?

[ME 109]

I used to be a trainee locomotive driver, have driven a steam train, and killed a 247 crank.
The oil pressure light will have the final say at idle?

[Rob Frankham]

I think the disagreement here is whether a vehicle that 'gets me to work and back everyday', is 'running great' To my way of thinking an enginethat rattles, bangs and smokes isn't 'running great' by any stretch of the terminology or imagination...

Running a vehicle till it's so worn out that it won't function any more is one thing but actually rebuilding an engine with components that are way beyond their sell by date is quite another.

Rob

[Rob Frankham]

I used to be a trainee locomotive driver, have driven a steam train, and killed a 247 crank.
The oil pressure light will have the final say at idle?

You've gone one 'better' than me then... I've worked on them but never actually driven them... Steam Locos that is..

Rob

[gspd]

Communicated with Joe at Max BMW after receiving this, it looked like they could do type 247 crank regrinds with that machine.

max.jpeg (134.41 KiB) Viewed 906 times

When I asked about the counterweight issue he replied:
"If you look at the crank in this diagram (see photos), you can see the separately attached counterweights.
We can't remove those to access the rod bearing journals for grinding. I'm checking to see if there are any other options. "

[kmisterk]

Alright guys. Take a look at this.

https://imgur.com/a/5hmHLD4

what do you think?

[gspd]

Alright guys. Take a look at this.
what do you think?

Looks OK from here
Now you have to install the con rod with new shells.
Oil the inside of the shell (where it contacts the crank),
leave the outside of the shell (where it contacts the rod) dry.
Torque the bolts to 35 ft/lbs.
You should use new bolts.
Once torqued, the rod should move freely on the crank, but have no perceptible 'in & out' play in every crankshaft position. Lots of side to side movement is normal.
If you don't feel any 'in & out' play, you're good to go.
Good luck!

[kmisterk]

Alright guys. Take a look at this.
what do you think?

Looks OK from here
Now you have to install the con rod with new shells.
Oil the inside of the shell (where it contacts the crank),
leave the outside of the shell (where it contacts the rod) dry.
Torque the bolts to 35 ft/lbs.
You should use new bolts.
Once torqued, the rod should move freely on the crank, but have no perceptible 'in & out' play in every crankshaft position. Lots of side to side movement is normal.
If you don't feel any 'in & out' play, you're good to go.
Good luck!

Right on. Thanks for the tips. Gonna get the shells next week and install. If they don’t jiggle jiggle, I will then buy the rest of what I need to button it back up and get her running once more.

[Rob Frankham]

Alright guys. Take a look at this.

https://imgur.com/a/5hmHLD4

what do you think?

It looks quite good... but I can't help thinking that you've removed a lot of material from the journal to get it to that point. I would want to mic the journal before proceeding.

If you do reassemble with standard shells the best way to check for wear is to move the small end sideways while measuring the movement of both the big and small ends. any difference in the distance they move denotes an undersized crank journal... or barreling, neither of which are good.

I'm hoping you 'get away with it... but I have my concerns.

Rob

[kmisterk]

It looks quite good... but I can't help thinking that you've removed a lot of material from the journal to get it to that point. I would want to mic the journal before proceeding.

If you do reassemble with standard shells the best way to check for wear is to move the small end sideways while measuring the movement of both the big and small ends. any difference in the distance they move denotes an undersized crank journal... or barreling, neither of which are good.

I'm hoping you 'get away with it... but I have my concerns.

Rob

I’m hopeful. I’ll be sure to post an update.

[kmisterk]

If you don't feel any 'in & out' play, you're good to go.
Good luck!

I tested both sides after reinstalling shells. Both sides feel basically identical as far as axial play. Only a small amount of squishing sound can be heard if you listen enough to the oil moving when you attempt to move it forward and backward. Rotation is smooth and no grinding or any other negatives are observed.

any difference in the distance they move denotes an undersized crank journal... or barreling, neither of which are good.

I'm hoping you 'get away with it... but I have my concerns.

Rob

Doing this lead to no observable difference at the 16th of an inch scale. I tested at four different crank positions, essentially TDC, BDC, and 90 degrees both ways. All positions equal out the same difference in side-to-side sway, leading me to believe there is no barreling, and it is properly rounded with no tapered edges.

My Next Concern

Is it normal for this much gap to be present before tightening down the valve screws? This is as far as I’m able to make this barrel slide. I’ve used a great deal of hand-powered force, attempting to press it flush against the body.

I don’t want to continue attempting until I get a sense of if this is normal or not.

Album on imgur: https://imgur.com/a/JG9hPQH