[Digitalinkartist]

Can anyone confirm if the N54 short block is the same casting as the N52 short block. If so, will a n52 head bolt up to a n54 block?

Bore and stroke are identical.
The material spec is different.
N54 is aluminum with iron sleeves.
N52 is Magnesium with aluminum sleeves.

From the pictures I have gathered they appear identical.
Anyone have first hand knowledge?

TIA

[pinoye90]

N52 Frankenstein swap!!!

[631twentyeighteye]

I've always wondered if it was possible to take the n54 block, mate it to an n52 head, throw on the ESS supercharger and crank the boost and see what happens.. now that'd be a fun car.

[Digitalinkartist]

Originally Posted by 631twentyeighteye

I've always wondered if it was possible to take the n54 block, mate it to an n52 head, throw on the ESS supercharger and crank the boost and see what happens.. now that'd be a fun car.

It certainly would diminish block grenade fears and x-out the the need for current aluminum n52 head bolts. Still need a solve for fuel limitations.

Again this is all on the assumption that it would fit. Anyone?

[hassmaschine]

pick up an N52 and an N54 head gasket and see if the holes line up.

N52 valves are larger than N54s as well so there could be piston/valve interference issues.

[Digitalinkartist]

Originally Posted by hassmaschine

pick up an N52 and an N54 head gasket and see if the holes line up.

Great suggestion and info.

[hassmaschine]

If you are lucky you can find a used one instead of having to buy a new one!

are the bore sizes the same? I'd think so. that would help with the shapes of the combustion chambers & pistons.

[Jashley73]

I'm sorry, but I just have to ask... Why?

[hassmaschine]

why not?

[Jashley73]

Lots of labor for a strong bottom end, with no improved power, heavier weight, and still stuck at 300HP until better injectors come along...

I hate to be that guy, but I'd just buy the 335...

[hassmaschine]

the idea does have some merit beyond 335i vs N52. The N52 head should flow better than the N54 (better ports, bigger valves, cams, etc). BMW couldn't fit both valvetronic & direct injection on the N54 (until the N55), but that doesn't mean it couldn't work with a turbo or a supercharger, obviously.

but, whatever. half you guys are afraid to change an air filter, so I can see how something like building a modified motor would scare you off..

[mike-y]

doesn't the N55 use a valvtronic head like the N52? What type of block does the N55 have?

[Jashley73]

Originally Posted by hassmaschine

the idea does have some merit beyond 335i vs N52. The N52 head should flow better than the N54 (better ports, bigger valves, cams, etc). BMW couldn't fit both valvetronic & direct injection on the N54 (until the N55), but that doesn't mean it couldn't work with a turbo or a supercharger, obviously.

but, whatever. half you guys are afraid to change an air filter, so I can see how something like building a modified motor would scare you off..

That's not the point. The point I was trying to make, was that the motor would already be hamstrung with the same 300hp limitation that the N52 already has. So you'd do all this work, and have an engine that's still no more capable than what you already have. An engine that weighs more than you started with too, no doubt...

You could lock-open the valvetronic and go with port-injection, but I guess I'm still missing the point... What's the goal here?

So you want the most volumetrically efficient, forced induction motor? Sounds great, in theory i guess. In reality, just up the boost and you get the same effect.

Want to get rid of *all* turbo lag? Put a supercharger on an N54 engine...

I guess I just don't "Get it"...

[hassmaschine]

upping the boost does NOT have the same effect as increasing VE. Upping boost pressure increases lag and heat; the power increase isn't linear. Increasing VE automatically increases HP (at the same boost pressure) without those drawbacks.

it's just a discussion. I mean, if you don't have something constructive to add, then why even post?

[hassmaschine]

Originally Posted by mike-y

doesn't the N55 use a valvtronic head like the N52? What type of block does the N55 have?

Yes. I believe the block is similar to the N54. Supposedly it has a cast crank instead of forged.

[Dan Bilzerian]

Originally Posted by Jashley73

Lots of labor for a strong bottom end, with no improved power, heavier weight, and still stuck at 300HP until better injectors come along...

I hate to be that guy, but I'd just buy the 335...

There are better injectors, but we should try to boost the fuel pressure first.

[CobraMarty]

Just add a second set of port injectors.

I have a used N52 head if someone has a N54 or N55 block.

Any advantage to either the N54 or N55 blocks?

[Jashley73]

Originally Posted by hassmaschine

upping the boost does NOT have the same effect as increasing VE. Upping boost pressure increases lag and heat; the power increase isn't linear. Increasing VE automatically increases HP (at the same boost pressure) without those drawbacks.

it's just a discussion. I mean, if you don't have something constructive to add, then why even post?

I understand all that, trust me. I just don't understand someone wanting to go through with this, or even spend time researching this once you think/reason through it, even just a little.

Trust me, I love my car and its motor. I also think doing a hybrid engine like this is just silly, because you're limited by the fuel injection no matter which short-block you put under the head. If someone figures out how to fuel an N52 enough to boost it to the point where it grenades, then yeah, its time for a new bottom end. But honestly, we don't even know how near/far we are from that point...

Constructive advice? Save your cash until we can fuel the engine... Right??

[Digitalinkartist]

Originally Posted by hassmaschine

the idea does have some merit beyond 335i vs N52. The N52 head should flow better than the N54 (better ports, bigger valves, cams, etc).

Well said,

Originally Posted by CobraMarty

I have a used N52 head if someone has a N54 or N55 block.

Good to know.

Bottom line is boost solutions will emerge for the n52 platform. Each new solve will be met with a new limiting factor. I am confident fuel delivery will be solved and when it is, block integrity will become a concern along with aluminum bolts. If I remember correctly, this was BMWs talking point for why they chose not boost the magnesium block.

[hassmaschine]

The head bolts that seal the block are not aluminum... Only the ones around what traditionally would be a timing cover.

[mike-y]

Originally Posted by Jashley73

I also think doing a hybrid engine like this is just silly, because you're limited by the fuel injection no matter which short-block you put under the head. If someone figures out how to fuel an N52 enough to boost it to the point where it grenades, then yeah, its time for a new bottom end. But honestly, we don't even know how near/far we are from that point...

Fueling can be handled by digging into the DME files and altering the fuel injection maps and make them work with larger injectors. there are other ways to do it, but the tuning capabilities are there.