Cross posting from E34 Forum:
Hey guys. This build has been in the works for the last 5 months or so and is still ongoing. Decided to build myself an M50B30 stroker from an M50B25NV. Why an NV? Well.... I already had one and my 92 525 is already an NV so why not.... Basis is M50 everything except for M54B30 Crank, Pistons, Rods. Relatively "well known" swap to get a cheap "S50 Clone" So I picked up a rotating assy from a local bmw guy from and got the ball rolling.
The doner: 10/91 MY 92 E34 Auto Sedan. 110k miles
Yoink
Spare ZF320 I snagged for $100 in the back. Has 95k ish miles
Taking head down
Blue alloy pad on a little grinder works wonders
Engine rebuild in a can
Home "hone" job. Bores were in good shape, just needed cleaned up
Ready for bearings. Got QC to sign off
finding bearings for this was a PITA. I needed a certain style and very few sellers actually knew what they had. Ended up getting some from ECS Tuning. Worked great
Measured crank before ordering bearings. Crank was in excellent shape. Makes sense since assy had 50k miles. Plastigauged with new bearings and was spot on. Torqued with new 10.9 grade bolts from Mc.Master Carr. Can't be worse than reusing the old
Difference of M50NV rod/piston and M54B30 rod/piston. M54 top
Was cleaning the rods and something wasn't right..... Bent Rod!! Got with seller and he fedex'd me two replacements. Top Notch guy.
Setup for my "polish" job.
That's it for now, stay tuned!
Looking good! Love me an e34.
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Is there anything new on this project?
I'm interested in this as I just bought at a local junkyard off a 330ci and want to attempt this on my m52
So, I did some more work on this build. Spare time is few and far between! Got the head 99% complete. Got valves all done, aside from the one that I still need a retainer for... Also, worked on the bottom end a little bit, got the piston rings sorted, and got the pistons/rods installed. Very happy to get the rotating stuff done.
I like this a lot! If I can't get somebody to buy my M50NV I just freshened up...this might have to happen to it!
Did some small things on this build recently over the holiday break. Cleaned and sorted a lot of hardware/ engine components. My Dad is building an M54B30 for his E39 530 sport atm so there is engine parts everywhere! Managed to clean, check torque on the pump nut and weld it to prevent it from backing off. Installed the pump and chain as well. Ordered new timing guides/tensioners since I really should anyway so waiting on them.
More to come
Will timing the cams be different
Was ready to install the head and was cleaning the surfaces when I noticed a CRACK from a valve seat running to a coolant jacket. Was more than a bit upset. I looked over the head quick when I received it from the machine shop, however apparently not close enough. I had the surface covered with tape to do the valves and only removed the tape in prep to install. Called around for quotes on repairs and they were in the $500-$700 range.... What are you gonna do? Sourced a loaded head from a local guy on the cheaper side and am redoing all of the cylinder head work. Had donor head pressure checked and cut and will be doing valves sometime soon. Stay tuned!
Donor head! has Aprox. 95k miles on it. Car was wreaked.
Let's start over!!
Got the new head polished, valves lapped and installed. Put on a new hg and installed the head. It's starting to look like something now.
do you shaved the block?the cams is 2 of 2.5 intake?
I make a m50b30 with head m50b25 non vanos,block m50b20(from 80 I go to diameter 84)with 1mm shaved the block.intake came from m50b30 because i want vanos,and on exhaus I put intake cam of m50b25 because they have 240 with 9.7 lift bouth of them
Mind explaining what you meant by the bearings were a challenge to find? Shouldn't they just be M50 Main bearings and M54 rod bearings? Am actually going through this next week when I order parts for my frankenmotor.
In theory, yes however early/late M50 engine blocks have different main bearing designs which are not interchangeable. I understand this picture illustrates m20 bearings, but IIRC this was the problem I had. The single tang was wider than the slot in the block to fit. The two tang style is the style I needed. Very few sellers actually illustrated what they had
thats a great bit of info! appreciate it. Will need to dig through my m50 box of parts and see which I need.
Hi guys, may I ask something as I'm currently also building a M50B30 with same exact specs; M50B25 NV with M54 internals. Everything is done and car ready for starting, however it doesn't start/run.. Problem is I bought 24lb injectors online, and it seems they're too big for the ECU to handle, even if we try to adjust it with a piggy bag chip.
Question, how can we make this work? Is it possible to change ECU use another Bosch ECU maybe the S50B30 or M52B28? Or will this not work?
Or do I have to go back to stock injectors? 18lb.. was told it will run too lean on high rpm..
Thanks a lot!
For an M50NV you cannot run another bmw DME aside from a 402. You also cannot change the maf away from a M50NV maf either. For an m50b30 I have been recomended at least 21.5lb injectors that can be easily found from in m52s. 24lb injectors are fine. What "piggy back" chip are you using? I will be using the Miller WAR setup that I currently have installed on the stock m50nv in my car. Are you sure everything is connected? Do you have spark? Is it timed correctly? With a complete build you just have to double check everything.
Thanks for the response, appreciated!
i managed to get the car running now with stock ECU and stock injectors for now. Air fuel ratio and ignition timing seems okay but it's only making 180hp on the wheels. I changed the exhaust cam replaced by another intake cam so now both 240/240. Power peak at 5600rpm only.. maybe timing of cams off?
So what else can/should I do? As you said for NV can't change computer or MAF correct? So what are the other options since my tuner is already tuning it with a piggybag (Unichip) in the Philippines, that's where I live currently.
i need more power from this clean build. help me pls guys
thanks,
Mike.
There is a bit of misinformation out there for "drop in" camshafts from either other engines or swapping "exhaust for another intake" camshaft. Very easy to mistime the engine. Yes on an m50NV you cannot run another DME or MAF to my knowledge. Changing injector size on your build (with tuning) some under drive pullies, headers (debatable) and maybe some other small upgrades might give you a bit of a boost. in power
Got the chain tensioners, sprockets and chained installed and timed today.
Any chance you could re-up these images with a host that didn't just shit on the entire internet? It would be greatly appreciated. I'm considering doing forged internals in my m50b25nv and was thinking about tossing in the m54b30 crank to gulp up a little more air.
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