Suggested "To Do's" M52B28 - Track Build

[Yayrea]

Hello once again R3v,

Bought in and purchased myself an iron block 1997 528i m52b28 with a zf 5spd transmission. I got the complete long block with transmission and ecu for $500. It was pulled from a 528i that had been in a rear end accident. The original owner was going to use it for his Mitsubishi Mighty Max drift truck but decided to go a different route. He said it had been sitting in his shop for about half a year now. It ran when he pulled it (i took his word for it since it was a complete engine/tranny/ecu/harness combo). Said it had around 160k miles on it.

Im currently dismantling my m20b27 from my 85 325e. If you need any parts let me know (Oil pan sold).

I plan on tearing this down and doing a slight rebuild (gaskets and such) since this e30 will be tracked. I purposely looked for the iron block m52 so i could have the 2.8l and throw a turbo on it without having to stress about the aluminum block.

Im going to do the s52 cam, m50 manifold etc on this build as well. I want to do everything now while its out of the car. Was wondering about boring it a tad bit and trying to reach that 3.0L then add the cams, manifold, tune, turbo etc...


I know you dont want to bore too much especially when running a turbo. What size bore do you think i could get away with on the m52 iron block with a turbo.

Any recommendations what you would do with this build if you were going to do it yourself. I wanted to go s5x swap but i found this to be a better bargain. Now i need the POWA! I live in Sacramento area and would like to start hitting the track in Sonoma after the swap is complete.

Looking for guidance and suggestions before i start buying parts and tearing her down.

Thanks

[ZekeTheSneak]

The block is the same as an s52, you can bore it out to Stock s52 or a bit farther. Honestly with the success the guys on bimmerforums are having with just turboing the stock m52. I would stick to that. Around 10lbs with arp head studs, cometic head gasket and you are partying around 300-400 hp. Keep it obd2, Can handle boost and much easier to diagnose.

[Yayrea]

The block is the same as an s52, you can bore it out to Stock s52 or a bit farther. Honestly with the success the guys on bimmerforums are having with just turboing the stock m52. I would stick to that. Around 10lbs with arp head studs, cometic head gasket and you are partying around 300-400 hp. Keep it obd2, Can handle boost and much easier to diagnose.

So id like to bore it from the 84mm to the 86.4mm depending on the quotes from the machine shops here in Sacramento/Bay Area. Add the s52 cams and crank, with the m50 manifold. I was definitely going to keep it OBD2 with EWS delete. Havent got too far into what else im going to have deleted with the flash. Need to find the right turbo/setup for this track build as well. Would like to reach the 500 mark on the hp. Although 400 doesnt sound bad for less work. Would like to replace my clutch and flywheel when i start breaking it down. What are my best options for the zf trans with 3.2L m52 turbo



My e30 is still waiting on subframe reinforcement and new suspension/brakes before this engine build gets started on. Giving me plenty of time to research and make up my mind. Along with gathering parts.

[digger]

how hard is it to find an S52 short block?

[ZekeTheSneak]

In the states not too hard.

[philakamrbean]

86.4 is about the most these blocks can be punched out to if FI. NA will usually take 87mm. The walls get thin after that. Bored my M50 block to 86.4 for the S52 rotating assembly (vs a used block and dealing with that issue).

[philakamrbean]

Oil pan baffle, oil pump nut safety wired. I'm running an s54 filter housing for the oil cooler (vs a cap with fittings), stewart water pump is highly recommended, and get rid of the plastic t-stat housing.

For the ZF, replace the detents to repair the 5th gear shifter lean (IIRC only 1 detent had to be replaced for this)

Disclosure, I'm doing a full rebuild on mine, bearings, rings, etc. Will be in the car next month for this season. Running s50 cams, turner ECU with chip for the cams.

[Yayrea]

So i have the opportunity to buy an S50 block with head and cams for a very low price. Now im wondering if i should buy that and sell the m52 but keep the zf transmission. So many options its getting stressful lol.

[Yayrea]

So i have the opportunity to buy an S50 block with head and cams for a very low price. Now im wondering if i should buy that and sell the m52 but keep the zf transmission. So many options its getting stressful lol.

Was just told the s50 block and head also has the s52 crank. I feel like it’s too good to be true but I’ll be checking it out tomorrow. Now what to do??

[TeXJ]

just found this thread. I'm liking it. I have a m52b28 in mine and just trying to get it to run correctly right now.

I may see if I can go back to obd2

[Yayrea]

just found this thread. I'm liking it. I have a m52b28 in mine and just trying to get it to run correctly right now.

I may see if I can go back to obd2

What did you get your 3.73lsd from? I'm looking for that same ratio for my e30

[TeXJ]

What did you get your 3.73lsd from? I'm looking for that same ratio for my e30

I bought the car swapped with the rear diff

[Yayrea]

Long time no talk r3v,

So i finally broke down the spare block i purchased. I have the hollow s50 cams and the blue s52 crank (same as m52 ive heard).. I believe the original owner told me he had it bored out and used a s50 head but im no 100% positive on that yet. I have the head and cams and trays removed. Im down to just the block, pistons and crank. Damn guy was smart, he welded the oil nut so i have to remove the crank the long way. He also had arp studs so he must have did some driving. I will be taking pictures (non phone) here this weekend with a nice updated post of all my progress.

Im still not sure what to do with my complete m52b28 engine (iron block). I want to get the most out of it that i can with plans of FI. I have already acquired my m50 intake manifold and my oil pan, sump, dipstick as well. The m52 will being teardown probably next weekend.

Suggestions, suggestions, suggestions.. I want to get the most out of the m52 and would like to do everything once while its out of the car and going through the rebuild.

Thanks a bunch.

[philakamrbean]

I'm unaware of the m52 and s52 cranks the same. The m54b30 and s52 cranks are the same. I'd be curious what he bored the block out to? I'd always thought for some reason the majority of the m5x engines were 84mm bore, but different strokes.


While in there if building it, chains, tensioners, make sure all the lifters are good if you've got a spare motor now. I took 48 lifters and found 24 good ones and took them apart, soaked in atf, and re-assembled them. I know in an ideal world, you'd replace them all, but $8 per lifter gets expensive and I whole-heartedly reject the concept of "you gotta pay to play" when it comes to some things. Some bits you have no options, but others you do.

[Northern]

M52B28 cranks are 84mm stroke, S50B30US is 86mm, S52B32 is 89.6mm.

M52 and S52 have provisions on the block and crank for rear mounted Hall effect crank sensor (US engines only I think, and may also be different for non-2.8L M52s) so keep that in mind if you're looking to throw any S50 bottom end stuff on the M52.

I'm a fan of a tiny tack between the oil pump nut and the shaft instead of the drilled nut/lockwire method.

S54 oil filter housing would get you a way to run oil cooler/thermostat and get rid of the plastic M52 oil filter housing.

Chain guides, upgrade to s52 timing chain tensioner, gaskets, rubber stuff for sure.


How much power are you really looking for?