1991 318iS M50 Build

[stormtrooper15]

Well I finally realized I bit off more than I could chew after building the bottom end and the engine sitting like that for roughly a year. I sent all parts for the swap to buddy in Houston who is now doing the work! The build must go on one way or another!

[stormtrooper15]

Finally got the pistons to the machine shop so they can measure them and bore the block accordingly. Now the next question, for my clutch, flywheel, pressure plate, and starter, I am thinking of going with a lightened M20 flywheel, M20 starter, and still undecided on what clutch but likely something to handle 500+ ft-lbs. I currently have an M50 and M54 flywheel, is there any point to me buying an M20 flywheel or can the M50 flywheel be lightened just as easily?

[stormtrooper15]

In all honesty, I started this build wanting 300 rwhp. But as I get more in to and issues arise, I'm opting to build the engine for way more than I'd ever likely use. With that said, I would expect this engine to easily put down over 500 rwhp. I may run it at that after I get used to the setup to beat my buddy with his new fancy mustang 5.0

[wworm]

power goals?

[stormtrooper15]

Got it sorted out! Gonna bore it to 86.5 mm and run forged CP pistons with Crower rods!

[stormtrooper15]

Alright, machine shop called today and they have to bore the cylinders. I’m trying not to blow the budget by going forged pistons so has anyone bored an M50 to 86.4mm and run S52 pistons with boost before? Any concern for wall thickness?

[pazi88]

Hmm MS3 or Miller war? Any inputs?

ms3 no doubt.

[stormtrooper15]

Hmm MS3 or Miller war? Any inputs?

[stormtrooper15]

Tomorrow the block and head go to the machine shop! Hopefully get them back in a week

[stormtrooper15]

Got the M54 on the engine stand and removed all accessories. Awaiting my amazon delivery of the special long E12 socket to remove the head.

[stormtrooper15]

No progress today because I made a little road trip....

[stormtrooper15]

Lots of progress last night! M54 teardown is up next!

[stormtrooper15]

1991 318iS M50 Build

Final displacement should be 2.98 L if my math is correct. Looking at a PTE 6262 .68 a/r turbine side and .70 a/r on compressor side. Anyone have any input on this turbo setup? Any issues with the .68? I was originally looking for an .81 but found a .68. I think it’ll make 400 rwhp and spool quickly which would be ideal. I’d go with a 2.93 diff to get better MPGs on highway

[stormtrooper15]

Got the M54 back safe and sound!

[stormtrooper15]

I just got off work and headed to pick up the M54 now, I’ll get back with you on final displacement. But I assume somewhere in the 2.9-3.0L range. Probably closer to 2.9 after machining and what not