What to look for when tearing down short block?

[pdx 528e]

I know it's not an E30, but I have an 83 528e which I threw an 84 eta motor in last month. I had to because it developed a wrist pin knock which was getting worse on cold mornings. I decided to join r3vlimited because the E28 sites do not have too many members with enough M20 knowledge.

My plan is to tear down and rebuild only that which is necessary in the bottom end, which would hopefully be wrist pin bushings, wrist pins, and maybe rods. Then I would like to bolt on a 323i head after having it reworked by a machine shop and tapped for the motronic rotor adapter. After tearing the head, manifolds, etc off the old block (which was bored with oversize +1 pistons 46k ago) I was wondering where to start. Do I measure every component against the Bentley specs with micrometers? Which parts are more likely to be worn and need replacement?

The combustion chambers were lightly carboned but seemed clean and healthy, the crosshatch is still completely visible within the bores, and there is no noticeable ridge at the top of the ring travel. The 323i 731 head is complete but will need new valves and a regrind. I'm letting a machine shop handle the head so I am more focused on learning how to rebuild the block at the moment.

TIA

[mops]

I dunno about the mechanical things, but once you got 323 head on e block then you will need 325i ECU, which will involve swapping out whole engine wiring loom, etc. alot of work and i'm not sure whether i.e. your tacho or ecenomy gauge would work afterwards....

[pdx 528e]

I dunno about the mechanical things, but once you got 323 head on e block then you will need 325i ECU, which will involve swapping out whole engine wiring loom, etc. alot of work and i'm not sure whether i.e. your tacho or ecenomy gauge would work afterwards....

Thanks, I'm comfortable with wiring up the management, however I am having trouble finding an 88 528e harness. I'll be playing around with stock management when the engine is done so I can get a baseline before Motronic 1.3.

[PeaveyBassist]

I have a harness from an '88 325i if you want it.

Will

[Sean]

I know it's not an E30, but I have an 83 528e which I threw an 84 eta motor in last month. I had to because it developed a wrist pin knock which was getting worse on cold mornings. I decided to join r3vlimited because the E28 sites do not have too many members with enough M20 knowledge.

My plan is to tear down and rebuild only that which is necessary in the bottom end, which would hopefully be wrist pin bushings, wrist pins, and maybe rods. Then I would like to bolt on a 323i head after having it reworked by a machine shop and tapped for the motronic rotor adapter. After tearing the head, manifolds, etc off the old block (which was bored with oversize +1 pistons 46k ago) I was wondering where to start. Do I measure every component against the Bentley specs with micrometers? Which parts are more likely to be worn and need replacement?

The combustion chambers were lightly carboned but seemed clean and healthy, the crosshatch is still completely visible within the bores, and there is no noticeable ridge at the top of the ring travel. The 323i 731 head is complete but will need new valves and a regrind. I'm letting a machine shop handle the head so I am more focused on learning how to rebuild the block at the moment.

TIA

If you're going to have the motor apart, at the very least, I'd replace the bearings. You mention the 1mm overbore pistons 46k ago? Does that mean the motor was rebuilt 46k miles ago?

[pdx 528e]

If you're going to have the motor apart, at the very least, I'd replace the bearings. You mention the 1mm overbore pistons 46k ago? Does that mean the motor was rebuilt 46k miles ago?

Yup, rebuilt 12 years ago due to cylinder wall scoring (metal in oil?), car sat for 9 years. I took it on as a project, and it ran great until the wrist pin tapping. I'll get a set of bearings.

Your thread looks awesome.

[Sean]

Yup, rebuilt 12 years ago due to cylinder wall scoring (metal in oil?), car sat for 9 years. I took it on as a project, and it ran great until the wrist pin tapping. I'll get a set of bearings.

Your thread looks awesome.

Thanks man! :) I need to get more pictures up there, been busy!

If you're getting new bearings, then that's all I'd really do if it was rebuilt. But, since it's apart, I'd also do rings and a honing - but I suppose if you wanna reuse rings it wouldn't matter much. Probably easier to do that since you have oversize pistons, and new rings probably wouldn't be cheap.

[pdx 528e]

I have read that the white shell bearings for the intermediate shaft are NLA. How does one remove the shaft for inspecting the bearings, or is this a non issue for most used blocks?

[nando]

you can't replace the bearings.. but they don't normally wear very much. if you are having your block tanked, just leave the shaft in - it will protect the bearings from the chemicals.

[Sean]

you can't replace the bearings.. but they don't normally wear very much. if you are having your block tanked, just leave the shaft in - it will protect the bearings from the chemicals.

I left mine in. It rotates pretty freely, so I'm thinking that it's probably fine.

[cunninglinguist]

For some reason the ETK doesn't show the # for the intermediate shaft bearings, but here they are.


==============================
11 11 1 264 196 - BEARING BUSH
11 11 1 280 863 - BEARING BUSH
==============================

[nando]

AFAIK you can only get new bearings with the block; BMW doesn't sell them seperately. that's why I said they can't be replaced, but maybe somebody has come up with an aftermarket supply by now.