Head Swap .... Question about Lifters!

[Nacanowhere]

Alright.. I'm swapping an S52 head ... with S50 cams onto my M50 block.

http://forums.bimmerforums.com/forum...d.php?t=949104

theres the link in the lame e36 section.

I came here with my question because it is technical and those guys are largely worthless:

6 of the lifters supplied with the cam trays are not useable, broken, dented, scored, or the little button in the center will not spring up.

My friend BMuu brought over some M52 lifters... which fit in the cam trays of the S52, but are obviously different casting. We are wondering if these are interchangeable? The spring button which contacts the valve is the only variable in question... we're not sure if the M52 and the S52 lifters are the same height internally!

The M50 lifters most definitely do not fit in the S52 cam trays... The M52 lifters slide right in as if they belonged in there... but may not work well or at all in conjunction with S52 lifters (18 of which are good to go).

Please advise!

Thanks guys

Chris

[BMuu]

your friend Kyle? Sounds like a pretty nice guy just to give you parts

[techno550]

M52, S50, and S52 lifters are identical.

[Nacanowhere]

hmm... I wouldn't go so far as to say "identical" that would imply visually nothing is different between them... when these clearly are identifiable. I'll try and get some pics.

Whether they are interchangeable or not is what I'm wondering.

[///M3///M5]

hmm... I wouldn't go so far as to say "identical"

I Would...

[BMuu]

Side by side they do not look the same. The sleeve on one is definitely longer and the oil passages on the side are slightly different.

[Nacanowhere]

.... I wouldn't

Top and side view of lifters, on left is S52 lifter, and right M52.

Should I still go ahead?

[kendogg]

M52, S50, and S52 lifters are identical.

hmm... I wouldn't go so far as to say "identical" that would imply visually nothing is different between them... when these clearly are identifiable. I'll try and get some pics.

Whether they are interchangeable or not is what I'm wondering.

.... I wouldn't

Top and side view of lifters, on left is S52 lifter, and right M52.

Should I still go ahead?

According to RealOEM they're all the same P/N (S50, S52, M52).

Perhaps just machining differences from different suppliers??

[milKt]

Or the S52 head you got has been "worked" before
or
the BMuu provided lifters are from a head that's been "worked"
or
BMW uses different suppliers/manufacturers (as has been noted.)

[Nacanowhere]

Scary stuff... would hate to assemble the rest of the head only to fire it up and learn they don't run well together!

Also could the souce of ticking lifters be that the small buttons that are spring loaded are no longer springy? A few of the lifters I have are fairly stiff and don't depress at all.

[kendogg]

Or the S52 head you got has been "worked" before
or
the BMuu provided lifters are from a head that's been "worked"
or
BMW uses different suppliers/manufacturers (as has been noted.)

How would 'working' the head change anything with the lifters though?? Nothing that I know of short of a solid lifter conversion would require a change in the lifters.

[milKt]

just offering possibilities.

How you explain this?

[kendogg]

just offering possibilities.

How you explain this?

I'd say different suppliers/build dates personally, but thats obviously not 100% fact. OTOH, not sure how mixing and matching them would work either. I'd say you might be better off buying all brand new lifters. Good PM, they aren't THAT expensive. Not cheap, but under $500 for a full set, iirc.

[Nacanowhere]

16.50 each... x 24 = 396$


only 6 are really unusable and missing... but if I order 6 new.. and they're different from the 18 existing I'm hurting all over again.... shitty.

[techno550]

I read the first post again...

The "button in the middle" does not automatically spring up. it requires oil pressure to do that. The lifters appear to be the same bore, with the same height, and the same height for the oil groove. They are the same.
How are they different?

[Nacanowhere]

oil groove is visually different, as seen in the photo... also in the cup... the casting is different, a bead of metal stretches down the m52 lifter.

I see.. the button requires oil pressure... about 20 of the 24 lifters i have picked out are very springy during cleaning/inspection.