[Joethecarguy]

Does anyone know if a n54 forged crankshaft (and rods) will fit in a n52?

[rothwem]

Aw snap, is this another high-hp N52 turbo build coming along?

To answer your question, I have no idea.

[rjahl]

Originally Posted by Joethecarguy

Does anyone know if a n54 forged crankshaft (and rods) will fit in a n52?

Why?

I think it's been proven that other parts of the motor let go first. Digidon and BPC have managed to pull heaps of power from the stock bottom end.

[Terraphantm]

Originally Posted by rjahl

Why?

I think it's been proven that other parts of the motor let go first. Digidon and BPC have managed to pull heaps of power from the stock bottom end.

It would increase displacement a little too

[hassmaschine]

Why did you post this in multiple sub-forums?

Yes it will fit. No it's not worth the effort. The stroke increase from N54 to N52 is tiny. And you need custom pistons because the N54 bore is different.

[F31cruisin]

You should look into the MILV's

[Joethecarguy]

New to e90post, accidentally posted in the wrong spot and can't delete it. Goal is 300 whp naturally aspirated, just don't like the idea of spinning a cast crank real fast.

[rjahl]

Originally Posted by Joethecarguy

New to e90post, accidentally posted in the wrong spot and can't delete it. Goal is 300 whp naturally aspirated, just don't like the idea of spinning a cast crank real fast.

What do you call "real fast"? From what I read 7,600 RPM seems to be the limit for the hydraulic lifters. BPC has pushed one well past that. The N52 loves to spin, the hard part is making power past 7,000 RPM.

[Bob@BPC]

Originally Posted by Joethecarguy

New to e90post, accidentally posted in the wrong spot and can't delete it. Goal is 300 whp naturally aspirated, just don't like the idea of spinning a cast crank real fast.

spun the stock cast crank to 8200 -8600rpm a ton on the dyno and then turbo'd the same engine and made over 500rwhp on it.

[Noir]

Originally Posted by Bob@BPC

spun the stock cast crank to 8200 -8600rpm a ton on the dyno and then turbo'd the same engine and made over 500rwhp on it.

That let off at the end, though...
that was awesome!

[Joethecarguy]

Was thinking underdrive pulleys, 3 stage manifold or velocity stacks, headers, exhaust, tune, lightweight flywheel, etc. What is the limit rpm for the stock valavetrain and was any power found that high in the revs?

[hassmaschine]

What are you going to underdrive exactly? The waterpump is electric, the alternator and AC only run when needed. You're going to gain 0.1hp from the PS?

[Joethecarguy]

I think you're right now that you mention that. I'm used to older cars lol

[Torgus]

Has anyone made 300whp NA on the n52? Honest question.

[W37V]

Originally Posted by Torgus

Has anyone made 300whp NA on the n52? Honest question.

Someone posted about their race engine while back and said it was making over (iirc) 320whp. I think few other race shops came close to it.

Among the regular folks, I think BPC managed to extract the most from it, but that was just with different intake, exhaust and headers. Iirc, they were over 260. I think with cams, or milvs, they could’ve squeezed few more whp.

Considering that stock 335 or stock e46 make about 270 whp, getting 260 out of it would be awesome. N52 would still lack tq of those engines, but that could be somewhat rectified by swapping in a higher ratio dif.

I’m currently at over 240 whp. Car is def not a slouch in any way.

[Joethecarguy]

I know the n52 from the 330i made 268horsepower. Headers would probably bring that up even higher. The difference on the 330i was the three stage manifold. That number isn't at the wheels though.

[JuniorB]

If you want to build a high hp na engine, this isn't it. There are thousands of treads of trying to make 250 rwhp out of a n52. With so little aftermarket support, your better off with a different car, or engine.

[hassmaschine]

Well that was pretty much all bolt on mods. Bolt ons are never going to do a lot on an NA engine unless it was poorly designed to begin with.

[JuniorB]

From looking into the n52 head, there is potential if someone was to create a high hp engine from this. It's to bad that there is little offered for this,it has when fbo, to have a smooth power band all the way to redline. Anyone looking to buy bolt ons for this should be in a hurry, turbos are coming on strong, pretty soon, what's left of the goodies may either become discontinued, or in small demand.

[MWagen]

bump...

So, just wondering if anybody has experimented with this at all? I know the N54 crank would only be 1.6mm more stroke, but a good used N54 crank can be found pretty cheap I bet. Then you'd just need pistons to accommodate the added stroke, maybe even modify the stock ones? Or be brave and bore the block for some custom oversize pistons if there's a machinist who will touch alusil. Seems like a cheapish recipe for a lightweight S52 equivalent, so wondering why nobody has bothered with it

[tdott]

Originally Posted by MWagen

Seems like a cheapish recipe for a lightweight S52 equivalent, so wondering why nobody has bothered with it

no one is rebuilding N52s.

With Spec E9x racing coming up, perhaps we'll see some money being dumped into an N52. But with junkyard motors usually only costing ~$900 it's easier just to slap one in and call it a day.

But I bet eventually someone will dump some money into one looking for a slight edge. Problem is, they are likely going to be hush hush about it so they don't get scrutinized.