Motor rebuild pics and some questions

[Jon K]

Got around to pulling the crank out today and everything looks good

http://e34.digital7.com/MotorBuild/IMG_8722.jpg

http://e34.digital7.com/MotorBuild/IMG_8726.jpg

All bearing surfaces look good.

However, I noticed in the front most cylinder bearing area (the one on the far right in the pic below) does not seem to have a oil squirter where the other cylinders did. I removed only 6 oil squirters from teh engine, though it almost looks like a hole in the first bearing there for an oil squirter... but it doesn't really go thru. This normal or did I drop something?

http://e34.digital7.com/MotorBuild/IMG_8729.jpg

[Jon K]

Additionally, I took the circlip off the post that holds on the longer of the two chain guides...

http://e34.digital7.com/MotorBuild/bent.jpg

I didn't use much force at all, but it seems like the post that holds the circlip and guide seems to be bent??? Is this normal? I cannot find any indication of bending on the guide - this is afterall just the timing chain guide, there cannot be THAT much crazy pressure to bend a rod like that.. what's the deal?

[632 Regal]

pop the bearing shell and see where the oil orfices are located.

[sKilled]

Hey is there an Idiots Guide to rebuilding the m50? Mine is overdue but I have no clue (hey that rhymes). I feel up to the challenge though, seeing as you fellows are so quick on the ball. If it hadn't ben for you, I would have had to pay some jackass $300 to change my discs, but you lot gave me the confidence to do it myself (change the discs and pads I mean).

[Jon K]

Heh motor rebuild is a little more detailed than brakes - but thats where i started!

[632 Regal]

Jon I just noticed that the bearing shells are out. The oil passage is open under the shell so oil pressure is being fer the every orfice under there.

[Bill R.]

closeup pic of the number 3 main crank throw, next to that rod throw pic you have?



.
Heh motor rebuild is a little more detailed than brakes - but thats where i started!

[Dave M]

Lookin good Jon.

Got my little M50 rebuild completed. Been drivin around fro a few days now, all looks well.

I'll be posting some final pics when i get a chance.

Keep us 'posted'

Dave M

[yaofeng]

Additionally, I took the circlip off the post that holds on the longer of the two chain guides...

http://e34.digital7.com/MotorBuild/bent.jpg

I didn't use much force at all, but it seems like the post that holds the circlip and guide seems to be bent??? Is this normal? I cannot find any indication of bending on the guide - this is afterall just the timing chain guide, there cannot be THAT much crazy pressure to bend a rod like that.. what's the deal?

Is that work in progress or you already have the problem solved. The timing chain guide hinge is bent. I don't know how you can bend it back. I had the impression it was threaded. You may be able to remove it and get one new.
http://i21.photobucket.com/albums/b274/yaofengchen/BMW_95_525i/DSC_1711.jpg

[bjl4776]

Wow man. I still am amazed at that engine. And every picture you post makes me wish i didnt sell it more and more. Granted i dont have the money to do what your doing, and im glad its going to a good home and a good cause. I beat the hell out of that engine, and it definately doesnt show the wear of a 212k engine w/ a turbo on it.

[genphreak]

Wow man. I still am amazed at that engine. And every picture you post makes me wish i didnt sell it more and more. Granted i dont have the money to do what your doing, and im glad its going to a good home and a good cause. I beat the hell out of that engine, and it definately doesnt show the wear of a 212k engine w/ a turbo on it.Yep, amazing stuff the way these last (esp. given the 7 year life most engines are built for these days). It is as if good oil and coolant will look after everything inside the engine that a bad bmw driver won't...

Jon- those bent shafts probably come true once the block heats up. Do they locate within the timing cover housings? These would maintain a lower operational temp than the block itself so they may need to do strange things to spec the stress on the timing cover castings- (or risk splitting them as they are alloy), let alone keepthe location of all the timing gear within spec. I am sure it would be an issue that that they'd allow for, or it might just be the casting design and how it expands and contracts at those locations.

I've seen similar things specified in production. However surely one of the wise few will have noticed this on your block (or others) whenst doing rebuilds in the past and be able to confirm or debunk this theory.

Are there are no signs of incorrect wear nearby?

[yaofeng]

Jon- those bent shafts probably come true once the block heats up. Do they locate within the timing cover housings? These would maintain a lower operational temp than the block itself so they may need to do strange things to spec the stress on the timing cover castings- (or risk splitting them as they are alloy), let alone keepthe location of all the timing gear within spec. I am sure it would be an issue that that they'd allow for, or it might just be the casting design and how it expands and contracts at those locations.

I've seen similar things specified in production. However surely one of the wise few will have noticed this on your block (or others) whenst doing rebuilds in the past and be able to confirm or debunk this theory.

Are there are no signs of incorrect wear nearby?

You cannot be serious thinking the bent shaft will return to normal once the engine heats up. The M50 engine is good. But it cannot perform magic. With the shaft bent like that, he cannot even put the timing chain guide and the timing chain back on. And remember prior to 9/1994, all M50 and M50TU timing chain guide are cast aluminum. Although you can replace it with one plastic. You cannot remove it with the head on without breaking it in two.

http://i21.photobucket.com/albums/b274/yaofengchen/BMW_95_525i/DSC_1705.jpg

[Jon K]

You cannot be serious thinking the bent shaft will return to normal once the engine heats up. The M50 engine is good. But it cannot perform magic. With the shaft bent like that, he cannot even put the timing chain guide and the timing chain back on. And remember prior to 9/1994, all M50 and M50TU timing chain guide are cast aluminum. Although you can replace it with one plastic. You cannot remove it with the head on without breaking it in two.

http://i21.photobucket.com/albums/b274/yaofengchen/BMW_95_525i/DSC_1705.jpg



The timing chain guide aluminum arm came off with it bent like that. I am sort of thinking maybe it bent while the chains were not totally free and we were trying to get the crank pulley off... maybe a chain bound up and for some reason put pressure on that shaft. I am going to use a lead hammer and bend it back true - its thick.



Bill - what exactly did you need a pic of? Im not crabby, but for what reason - do you see something wrong? I am at school now so the pic will come later this week unless I took a pic of it and didn't realize. Will look.

[genphreak]

You cannot be serious thinking the bent shaft will return to normal once the engine heats up. The M50 engine is good. But it cannot perform magic. With the shaft bent like that, he cannot even put the timing chain guide and the timing chain back on. And remember prior to 9/1994, all M50 and M50TU timing chain guide are cast aluminum. Although you can replace it with one plastic. You cannot remove it with the head on without breaking it in two.On a second look you are probably right. Given that the shaft is bent, not the mount itself, it is probably damage some way. Thing is the other shaft in the middle looks skewed the other way- maybe just the pic tho.

Unless they were bent some way during teardown I just can't imagine another way it could happen on the engine without a major problem.

[winfred]

most likely the engine was turned over with some force with the chain loose and it bunched up and wedged the pin cockeyed


Unless they were bent some way during teardown I just can't imagine another way it could happen on the engine without a major problem.

[genphreak]

most likely the engine was turned over with some force with the chain loose and it bunched up and wedged the pin cockeyedMaybe one of those S&M gals from that trailer park has been hangin' around Jon's workshop the last few nights...