Boring a 3.0L engine

i remember reading of a S50 being bored to 3.1, and S54s bored and stroked to 3.3, and M52 bored and stoked to 2.9.

I have no issues with with stroking the 2.8L to 2.9L. I just really want to avoid the harmonics issue at all cost, but would like to get as much power out if an N/A motor as possible. I will be doing extensive head work.

I think +1 mm on the intake valves and +2 mm on the exhaust valves. Port and polish the exhaust side for Euro M50B32 headers and polish the intake side and add the M54B30 Intake Manifold to complete the flow.

I also am going to convert to Solid Lifters and run a hotter set of cams that match the flow of the head. Probably looking at a custom set of cams.

I'm going to invite Adam (PEI330ci) into this thread...

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Originally Posted by Hornung418

I have no issues with with stroking the 2.8L to 2.9L. I just really want to avoid the harmonics issue at all cost, but would like to get as much power out if an N/A motor as possible. I will be doing extensive head work.

I think +1 mm on the intake valves and +2 mm on the exhaust valves. Port and polish the exhaust side for Euro M50B32 headers and polish the intake side and add the M54B30 Intake Manifold to complete the flow.

I also am going to convert to Solid Lifters and run a hotter set of cams that match the flow of the head. Probably looking at a custom set of cams.

I'm going to invite Adam (PEI330ci) into this thread...

Sent from my DROIDX using Bimmer

I think you've got a lot of enthusiasm....but have been mislead.

Stick with the 2.8L crank if you want to avoid serious harmonics...and I would not use an overheated block/head for any performance rebuild. Once you roast them, they are dead in my book.

I've done a lot of work on M54 heads, and I'll tell you that there are things you don't want to do like opening up the exhaust port too much. You won't match an S50 euro header without tunneling into the water jacket, but you'll get close. My advice is let the head porter decide how big to go...but be prepared to send him 2 cylinder heads to get it right. (Been there, done that)

Valve sizes: 1mm on the intake is fine, the exhaust I would leave OEM @ 30.5mm. I was told not to increase the exhaust valve size by a cylinder head guru, but I decided I "needed" to for my own reasons. The result: 31.5mm exhaust valves flow less than 30.5mm valves by a marginal amount.

I have no idea what your budget is...but I'll tell you that you are looking at close to $10k for the cylinder head work and valvetrain you have listed above. Solid lifters and custom cams adds about $6k to an already big price tag.

My advice: Go FI

I have a line on a good race head job and hot cams, but I'll wait till I see results before I stand firmly behind them. No need to run a solid lifter to do 7500rpm, I've never even seen valve float in these motors.

Why would u not go with a S50 intake manifold. Don't they flow more than the M54 intake manifold.
Why would u

Thanks for chiming in, Adam. Advice well taken.

Originally Posted by snikwad

Why would u not go with a S50 intake manifold. Don't they flow more than the M54 intake manifold.
Why would u

S50 doesn't mate to the M52TU/M54 Head...I would like to keep the low end torque that the 2.8 has.

So suggested plan of attack: 30 mm Timesert the block, and go FI.

Thanks for your suggestions, all. Iceman, I await your thread about the race head!

correction, M50 manifold... th same maniforl USDM E36 M3 guys put on their M3s to get the top wnd back...

what about stroking the thing rather than boring? that would make more torque no? then run some top end cams and chip tuning to balance out the top end?

The whole goal is to avoid any awkward frequencies that would spin the OPN off the shaft. And judging from the countless hours of experience that Adam and Iceman have with this ordeal, I've decided to keep the 2.8 crank and get the correct Compression Ration pistons and supercharge the thing. ESS TS2 should be easy to save for in 2 years, on top of the other maintenance. Remember, this will be a direct swap into a 330 and will be a dedicated track whore with occasional commuting.