M52B30 - Couple of Questions

[Motorhole]

Okay, so my M54 donor is now in a well-ordered pile of bits, it”˜s time to think about how I”˜m going to go about this build. Having not done anything like this before, I have a couple of questions as follows:

1) I”˜ve been offered an M52B25 for a good price. Is this any use to me for building the M54 gubbins into? I already have an M50 mani, pink injectors etc on the motor currently sat in the E30. Are there any other differences I need to be aware of or is the B25 just as apt for receiving the M54 innards as the B28?

2) Other than the crank & conrod shell bearings, piston rings, oil seals and gaskets, what else is a good idea to replace? Timing chains? Oil pump drive chain? Oil pump rebuild? Timing chain guides?

3) Do I have to use the big ass harmonic damper crank pulley thing off the M54B30?

4) I”˜ve read (thanks f0xy!) that the M52 windage tray needs a little modding to clear the longer stroke crank. Can I use the M54 windage tray and oil pump instead or is that a no-go?

5) I”˜ve kept the lifter block, journal caps and lifters that go with the M54 inlet cam (ordered, of course). Is this a good idea or am I as well just dropping it into the M52 stuff?

I think that”˜s about it for now. Any help is welcome, many thanks

[motormanmick]

Hello Motorhole,

1) is the m52 block Nickasil, 1st of the alloy blocks suffered a problem with sulphur in the fuel destroying the Nickasil coating in the bores, so I would probably stay will the m54, then no need to worry, if it's not the Nickasil block, choose which ever is easier to install in the e30, not sure how the e34 325 sump goes from m52 to m54.

2) There is no mention of the distance/condition of the m54 or m52, but if you are going bearings/rings/oil seals/gaskets, I would replace all chains/guides/tensioners/oil pump rebuild minimum, depending on condition of block and pistons, a re-bore & pistons.

3) A guess, but use the m54 harmonic balancer, it's made to suite the m54 reciprocating mass and balance, someone else will confirm that for sure.

4) BMW put the m54 windage tray in there, stick with it (no mods required) oil pump guessing should be ok, oil pickup will need to suite e34 325 sump that you will fit.

5) can't help there

[Motorhole]

Thanks for the reply bud! The main reasons for the M52 are that I already have an M52 running quite happily in the car, complete with loom, EWS, ECU, gearbox, lightened flywheel, M50 manifold and E34 sump/pickup. I don't have the loom, ECU or some if the ancillaries for the M54 - so an M52B30 would be plug & play with my current setup. It's also a lighter engine and with a mapping session on a rolling road, numbers that others have obtained suggest it'll make a good bit more power than an M54B30.

Ideally I'll be sourcing a steel linered engine. Browsing OEM does suggest that the M52B25 blocks are a different part number and weight to the M52B28 blocks - though what the differences are, I don't know. Though heads are the same, albeit different part numbers for inlet cams. If anybody can shed any light on the differences between the blocks - or whether I can build the M54 bottom end into an M52B25 block, that would be great

Following your advice I think the full timing chain, ring, bearing & pump refresh is in order.

[mattxr2]

2.5 and 2.8 engines are identical apart from rods pistons and crank. My 3l has the inlet cam from an m54 and exh cam from a 328

I used the front pulley from the m52 to run the crank sensor, m54 has the crank sensor at the back of the block so the pulley can't be used

Use the m54 windage tray

Use a steel linered block. M54 block is different oil ways so don't match the head. ( sure iv read this is why it can't be used)


Could just buy my engine, put it in and go

[Motorhole]

Haha don't think I havn't considered that mate! I thought about it when you first put it up for sale. It's a very fair price too, especially given I could do better than break even on the M54 selling off the bits I've canabalised. But I do enjoy tinkering almost as much as driving and having never done any real engine work before, I'm keen to have the experience of a build under my belt

[HairyScreech]

Thanks for the reply bud! The main reasons for the M52 are that I already have an M52 running quite happily in the car, complete with loom, EWS, ECU, gearbox, lightened flywheel, M50 manifold and E34 sump/pickup. I don't have the loom, ECU or some if the ancillaries for the M54 - so an M52B30 would be plug & play with my current setup. It's also a lighter engine and with a mapping session on a rolling road, numbers that others have obtained suggest it'll make a good bit more power than an M54B30.

Ideally I'll be sourcing a steel linered engine. Browsing OEM does suggest that the M52B25 blocks are a different part number and weight to the M52B28 blocks - though what the differences are, I don't know. Though heads are the same, albeit different part numbers for inlet cams. If anybody can shed any light on the differences between the blocks - or whether I can build the M54 bottom end into an M52B25 block, that would be great

Following your advice I think the full timing chain, ring, bearing & pump refresh is in order.

I believe the different part numbers is because the blocks are supplied with matching pistons. B25 and B28 pistons are different.

[DanThe]

Oil pumps are very different between M52 and M54, as are the blocks, and cannot be interchanged
You must use the toothed front pulley, as Matt says
New chains and guides are a must, a new main tensioner is also worth fitting

Most M52/M54 cam trays are the same, so I would use the ones with the least scoring, always keep the matching caps. Get the cylinder head specialist to service the lifters, they get used to moving into one place after 100,000 miles or so and don't like moving beyond it when swapped around or used with new cams, they let you know about this with lots of ticking

[Motorhole]

Thanks for all the help guys, just the stuff I need to know. Just need to check out whether or not this B25 is steel linered.

Dan - on a similar note to the cam journal caps, is it worth keeping the main bearing caps that come with the crank too?

[motormanmick]

No, I wouldn't, stick with the caps that come with the block, these will be line bored in situe on the block at time of machining as part of the manufacturing process by BMW, if you change to the caps that come with the m54, you will need to resize and re line bore, it's not a throw them on and she'll be right.

[Motorhole]

Thanks mate, spot on

[Motorhole]

So I have an engine no. for this M52 and called BMW to see if they could tell me if it was a nikasil or steel linered block. They told me they don't have access to that information? Also said they couldn't give me a VIN from the engine number.

Not what I was led to believe - is this right? Any other way I can find out?

Thanks!

[DanThe]

[HairyScreech]

That said, a nikasil engine that has survived this long should be ok unless you want to fill the fuel tank up with shite fuel. It's the sulphur in poor quality fuel that does it.

Nikasil blocks can be rebored and recoated or etched into Alusil block depending on alloy I am led to believe.

These guys can do auto cylinders but at £130 a bore not cheap.
http://www.poeton.co.uk/coatings-automotive.htm

[Motorhole]

Thanks guys, looks like I might be sorted