97 528i engine question

[02stu]

I already have a 92 non vanos M50 in my 318is, and I'm buying a 97 528i motor which I might sell. If I don't sell it can I use the crank off of the motor, or anything else? What kind of gains would I get from swapping the crank? Would it stroke my motor out to a 2.8L?
Thanks
Stuart

[FredK]

Yes, but to stroke the engine you need the pistons and rods as well.

You're better off transplanting the entire bottom end if you want to go the stroker route. That way you don't have to replace any bearings or the expensive bolts that hold the bottom end together. UNLESS the engine has uber high mileage and needs a rebuild or something.

If you had a Vanos M50 I'd suggest doing an OBD-I swap on it, but since you have a non Vanos, the cheapest and most efficient route is to use the NV head and electronics on the 2.8L bottom end.

[02stu]

Thanks, what kind of kind of HP would I see from that? Is the block aluminum on these engines?

[DanThe]

I have one of these engines (in pieces) that im building the crank and rods/pistons into a N/V M50 engine. I dont know about yours but the UK 2.8's were alloy blocks, this particular one had steel liners that had moved in the bores and caused head gasket failure which is one of the reasons im building it into an iron block, I also like the N/V head and valve train.

[FredK]

All 3er and 5er 2.8L engines had a cast iron block.

Only the 97 and 98 Z3 received an Al block with steel liners.

[Mossman]

later 528's with double vanos (m52tu i think) have alloy blocks

[02stu]

I know its an iron block, what I need to know is if its worth it going to a 2.8L bottom end. It doesn't look like the 2.8L engines have a hp advantage but then again they are OBDII. I also want to keep the thick non vanos control arms can I use them with the 2.8L bottom end?
Thanks
Stu

[matt]

Actually you don't want to keep the thick non vanos connecting rods, even if you can.

Non-vanos bottom ends tend to explode when they overrev (instead of bending valves like the later M50TUs and S50s). You might be able to spin an NV head on a stock M52 bottom end much higher than either motor on its own.

[02stu]

Zionsville sells a 2.8L stroker kit which I assume is just the 2.8L bottom end and they claim 22hp. However I heard something about a OBD2 crank will not work with an OBD1 engine because the timing gears are different. Is this true?

[matt]

Nope.

[BimmerToad]

IIRC, the rest of the world M52 was an aluminum block, but in the US we got an iron block.

[02stu]

Thanks

[OoPEZoO]

I'm kind of in the same boat with my swap right now. I've got a non-vanos M50 torn down to the block right now. I've also got access to a low mileage 2.8 bottom end that I can pretty much have for free (minus my labor to remove it of course). I was thinking about doing it, but I wasn't sure of the finer details.......timing, software, other things that haven't crossed my mind.

Anyone out there have any concrete details on the swap? Is it as simple as bolting the non-vanos head and timing cover onto the 2.8 block, or is it much more involved? I can't believe it would be that simple.

[CarsSuck]

the valve train from the m52 is also a significant improvement over the older engines. You should really just swap the motor and use the parts you already have to swap to OBDI.

[OoPEZoO]

the valve train from the m52 is also a significant improvement over the older engines. You should really just swap the motor and use the parts you already have to swap to OBDI.

Thats not entirely true. From what I understand, the non-vanos motors have dual valve springs and beefier valve stems. Either way, I have pretty much already commited to the non-vanos top end. I have a low miles motor that I know the history of, and I'm not really interested in messing with a vanos unit.

I know I can swap cranks/rods/pistons and such to make a stroker, but since I have access to a good 2.8 bottom end (and just the bottom end, not the rest of the motor).....I was just curious if it wouldn't be easier to just bolt the 2.8 bottom end to the non-vanos head and be done with it.

I just don't want turn a 1 year engine swap into a 5 year project of fixing software and such when I'm done.