Oil Gallery Blocked, Damaged Case and Main Bearings (pictures)

[oseaghdha]

I am not proposing you try to remove the scratch, just the raised edges.
If the scratch bothers you, fill it with JB weld, although I don't think it's necessary.

[BigDick]

Myself I would use a full round (rat tail) file to remove it, that or a dremel tool but only if you have a VERY steady hand. lol, dremeling bearing surfaces = +9 pucker level I was thinking about the jb weld too but how would it hold up against pressures and stresses? worth a try though.

[62xs]

long ago they used to babbitt bearing. I've never done it but my 2c would be to try and solder the scratch with a good flux, small tv repair sodder and a soldering iron.

[pete_s]

How about just push the raised edges down with pressure from the round end of a ballpean hammer and slide it across, if the groove is still there just wet it with the Locktite products for just that purpose before you clamp the case together with the bearings.

Check a bearing supplier for that.


Disassemble (the shells should stay in place) and drop the crank in with plastigage and torque. If it meets spec clean the journals and reassemble with assembly lube and spin it without rods just to be sure there is no problem with your parts. If you don't like the looks of the journals polish them all up w/400 to 600 wet and dry paper with light oil. Do the rods the same in all respects.

[black 82xj1100]

It makes absolutely no sense that several metric boatloads of crankshafts would get larger over time so the only thing I can think of that makes any sense is that bunches of them are or were being welded up and reground back down to Yellow bearing spec!


Regards,

Scott

Around this time frame the Old school hotroders Would use a little undersized bearings for a looser engine good for a few extra horses for there drag engines.
This is more than likely whats happening with the yellow bearings.
Just a thought

[79XS11F]

The bearing shells are soft enough to mark with you finger nails. I would bet that unless the raised part of the scratches are real high, which they do not appear to be, that you could just put in the new shells and the slightly raised parts of the scratches would indent their way into the back sides of the shells and make no difference on the front side specs. Like how many 1000s of an inch high are the raised parts of the scratches as compared to just about everyone suggesting that you just use the largest replacement shells?
Rob

[pete_s]

No, I don't think so, those are shell bearings, the outside is steel and the inside is a babbit alloy

[Crazcnuk]

the way to establish your starting point is to take the crank and case numbers, find out what bearings came in it stock.

then put your cases together with the stock indicated bearings and plastiguage.

whatever your pg tells you will determine whether you go to the next thicker or thinner bearing.

i doubt you will have to go more than 1 step either way. unless something really nasty happens cranks don't wear that much.

if you don't have the stock brngs, but you have one size thicker i would start with those.

i can't see any reason you would ever have to go to the thinner bearings as, as was mentioned, cranks don't grow!

[79XS11F]

No, I don't think so, those are shell bearings, the outside is steel and the inside is a babbit alloy

My Mistake, I have not looked at them that closely but do know that the inside faces are rather soft. If they are 2 part metal with hard steel on the outside then NO, just installing them will not be a good idea.
Rob

[3Phase]

I think it's going to be okay

Thank you, all of you! I'll have the scratched crankcase and the messed up crankshaft checked at a machine shop to see if they're usable. If they are, my spare engine project has two more candidates.

I've been busy cleaning the original case for the last couple of days and, now that everything is, once again, clean enough to work with and measure: in both of the crankcases the upper bearing inserts had less wear than the lower inserts. All of the inserts, old and 'new', were within five ten-thousandths of an inch of one another. One insert was hopelessly worn to 0.0587" but the rest were between 0.0590" and 0.0592".

Bingo!

With some bearing substitution the 'new' crankshaft fits the old case. Oil clearance spec is 0.022~0.044mm (0.0009~0.0017"). I checked it four times, using Plastiguage and quarter-turning the crankshaft. The crankshaft has almost no wear or runout. The oil clearance is around the upper limit of 0.0017" but it will work.

To check the bearings without scratching them or getting a false reading from trying to use a flat micrometer on a curved sureface, I glued a piece of a broken 5/64" (0.0781") drill bit shank to the anvil of the micrometer.


Measuring the #4 lower main bearing insert (lower half of the thrust bearing). Subtract the drill bit diameter from the reading: 0.1372" - 0.0781" = 0.0591"


The last of the parts I ordered arrived yesterday and I have the gas tank hooked to the battery charger to see if that electrolytic rust removal technique works so now it's time to start putting everything back together.


Regards,

Scott

[petejw]

Looks like your on the right track,
let us know what the machine shop does with the case.

[3Phase]

Looks like your on the right track,
let us know what the machine shop does with the case.

Thanks, Pete, and will do on the case and the crank.

Right now I'm re-checking all of the gaps and clearances with the new piston rings. B. O. R. I. N. G.

The new, Standard, rings are slightly narrower and not quite as thick as the original rings. Some of the piston/ring side clearances are close to the limit.

I like black 82xj1100's suggestion -- it's going to be an Old School, HotRod XS with loose clearances for racing!

Regards,

Scott

[3Phase]

Oil Gallery Blocked, Damaged Case and Main Bearings (pictures)

REPOST

I bought some used engine parts that came from a low mileage (~14K miles) 1981 XS1100LH Midnight Special that, other than disassembly for sale, has not been touched since it was made back in 1981. 4W1-000719

I am attempting to repair the damage but cleaning and careful inspection have revealed an un-Godly amount of general stupidity and carelessness in evidence.

Main Oil Gallery Blocked Since 1981

The main oil gallery is partially blocked by a piece of metal protruding into the middle of it from the oil filter gallery.



The metal blocking the oil gallery is the lower threaded part of the casting for the Union Bolt (oil filter housing bolt). It was left there at the time of manufacture back in 1981 and no one has touched it since. Fortunately, it didn't break off!




Lower Engine Case Damage During Assembly In 1981

A large, deeply scratched line goes all the way across all five main bearing cutouts in the lower half of the engine case. The scratch damaged all five lower main bearing shells. Main bearing cutout #4, the lower half of the thrust bearing, is shown.





Lower Main Bearing Shells Damaged

The ten common bearing shells.




The damage to the back side of all five main bearing shells caused by the large scratch across all five bearing cutouts in the lower engine case.



The shiny spots in a line between the black marks show that the damage penetrated through the entire bearing and raised the bearing surface enough to wear against the crankshaft journals.

[3Phase]

I think it's going to be okay

REPOST

Thank you, all of you! I'll have the scratched crankcase and the messed up crankshaft checked at a machine shop to see if they're usable. If they are, my spare engine project has two more candidates.

I've been busy cleaning the original case for the last couple of days and, now that everything is, once again, clean enough to work with and measure: in both of the crankcases the upper bearing inserts had less wear than the lower inserts. All of the inserts, old and 'new', were within five ten-thousandths of an inch of one another. One insert was hopelessly worn to 0.0587" but the rest were between 0.0590" and 0.0592".

Bingo!

With some bearing substitution, the 'new' crankshaft fits the old case. Oil clearance spec is 0.022~0.044mm (0.0009~0.0017"). I checked it four times, using Plastiguage and quarter-turning the crankshaft. The crankshaft has almost no wear or runout. The oil clearance is around the upper limit of 0.0017" but it will work.

To check the bearings without scratching them or getting a false reading from trying to use a flat micrometer on a curved surface, I glued a piece of a broken 5/64" (0.0781") drill bit shank to the anvil of the micrometer.




Measuring the #4 lower main bearing insert (lower half of the thrust bearing). Subtract the drill bit diameter from the reading: 0.1372" - 0.0781" = 0.0591"



The last of the parts I ordered arrived yesterday and I have the gas tank hooked to the battery charger to see if that electrolytic rust removal technique works so now it's time to start putting everything back together.


______________

[motoman]

Even still, an interesting way to 'attack' the issue Scott.