[ar design]

Originally Posted by McLuVan

I believe the most powerful ones are about 400rwhp
400*1.12=448
yeah
that's about the limit right there

Based on?

[flinchy]

just thought i'd resurrect this thread for a laugh

show how a few years ago people were trying to say 500BHP (not even WHP) would be the N54's limit, and people are now starting to go past 700whp without opening the engine at all :P

[pwr hungry]

Holy thread revival! Any new info out there regarding metallurgical info about the N54 along with wall thickness and cylinder dimensions? If we have the sleeve/cylinder composition data and dimensions, I could work it backwards and tell you exactly how much pressure the cylinder could take before popping.

[crypticc]

Ask this guy. He's got all the info you need (unfortunately)

http://www.e90post.com/forums/showthread.php?t=893461

Originally Posted by pwr hungry

Holy thread revival! Any new info out there regarding metallurgical info about the N54 along with wall thickness and cylinder dimensions? If we have the sleeve/cylinder composition data and dimensions, I could work it backwards and tell you exactly how much pressure the cylinder could take before popping.

[Spoolin1]

This is some funny info. I say this because I have an open deck FRM sleeve stock block Honda S2k that wasn't meant for boost and is making 800+ whp (about 950 crank) on 34 psi with no issues and it's been like this for years. As a matter of fact, there are many stock block S2k's running around with 600+ whp with no issues. Even Laskey racing makes built open deck blocks for the S2k F20c and F22c that are making well into the 1000 whp arena. As long as you run good headstuds like L19's that will hold the pressure, open decks are very strong and will hold a lot of boost and power. Don't go get all caught up with this article because it's just plain BS.

[Dave W.]

Here's a true open deck block, it's from an old Porsche 944. Note the space between the cylinders, there's no support between cylinders like there is with the N54 block and other modern open deck blocks.
Also, the water jacket on the old Porsche is very deep which leaves the cylinders unsupported. In contrast, the bottom of the water jacket on the N54 is positioned halfway down the cylinder so the cylinder is supported at the pistons mid stroke. This adds quite a bit of rigidity at the point where the piston is seeing max thrust load. The old Porsche design let the cylinders move around slightly at high power levels which eventually wears down the headgasket, which is the reason I was able to take this pic.

[V8bait]

Nobody is going to ever make methanol dragster 2000+ hp numbers on an open deck aluminum block. Because that is relevant to anything.

Open decks can be strengthened if need be. At some point a limit will be found and people will accept it, be it 700whp or 1200whp. If you're building a funny car or a nascar you're not using a N54 is all I'm gonna say.

[Carl Morris]

What I found interesting going through this old thread is the example of the Mitsubishi motor. I never went through the V6 code but it was probably like the 4g63 code. The tables only supported up to about 14psi worth of load, which is why you had to run race gas at higher boost levels. The timing didn't continue to retard further as you added more boost. That changed later for the 1g 4g63s when we figured out how to double the load range of the tables at which point you could finally go kind of fast on pump gas without a standalone. It took until the EVO before the load range was made part of the table and could be changed in the table like you now see in the BWM code. That was why people blew up 90s Mitsu motors on pump gas.

[CSL335i]

Here is my rebuilt n54 engine. We converted it from open-deck to semi-open-deck design as we use some support inserted between the cylinder wall and engine wall.

[stratos_335]

Why not closed deck? Cooling issues?

[TT-Tom]

Pretty funny read now, based on current output levels

[Jeff@TopGearSolutions]

Originally Posted by flinchy

just thought i'd resurrect this thread for a laugh

show how a few years ago people were trying to say 500BHP (not even WHP) would be the N54's limit, and people are now starting to go past 700whp without opening the engine at all :P

LOL

This thread hurt my brain back then and it still does even today.

[SfValley335i]

Hmm wonder where op is now...

[flinchy]

Originally Posted by pwr hungry

Holy thread revival! Any new info out there regarding metallurgical info about the N54 along with wall thickness and cylinder dimensions? If we have the sleeve/cylinder composition data and dimensions, I could work it backwards and tell you exactly how much pressure the cylinder could take before popping.

i can take measurements if you want/need, have a block bare at teh moment. unless you mean much more specific metallurgy related measurements.

as for specific metallurgical info, you'd have to ask a BM engineer... cast iron sleeves is the only info probably anyone will have there lol.

[flinchy]

Originally Posted by Spoolin1

This is some funny info. I say this because I have an open deck FRM sleeve stock block Honda S2k that wasn't meant for boost and is making 800+ whp (about 950 crank) on 34 psi with no issues and it's been like this for years. As a matter of fact, there are many stock block S2k's running around with 600+ whp with no issues. Even Laskey racing makes built open deck blocks for the S2k F20c and F22c that are making well into the 1000 whp arena. As long as you run good headstuds like L19's that will hold the pressure, open decks are very strong and will hold a lot of boost and power. Don't go get all caught up with this article because it's just plain BS.

wow i had no idea it was open deck. fully too, even more than the N54... makes me even more amazed that those things can take 600-700+whp day in day out. One would hope the N54 is at least that strong haha

not like the N54's cylinders are fully floating and free to move as they please at least

still, always excited to see where the platform finally lets go

Originally Posted by Carl Morris

What I found interesting going through this old thread is the example of the Mitsubishi motor. I never went through the V6 code but it was probably like the 4g63 code. The tables only supported up to about 14psi worth of load, which is why you had to run race gas at higher boost levels. The timing didn't continue to retard further as you added more boost. That changed later for the 1g 4g63s when we figured out how to double the load range of the tables at which point you could finally go kind of fast on pump gas without a standalone. It took until the EVO before the load range was made part of the table and could be changed in the table like you now see in the BWM code. That was why people blew up 90s Mitsu motors on pump gas.

i didn't check the thread.. but 6a12TT? from the VR4's/300gt? or an older motor pre-evo? interesting hearing history like that.

Originally Posted by stratos_335

Why not closed deck? Cooling issues?

well yeah, the motor already runs hot, just imagine it with slightly worse cooling yet again?

pre-oil cooler days wouldn't only have seen motors limp mode, but likely totally blow.

[3000GT MR]

Originally Posted by flinchy

wow i had no idea it was open deck. fully too, even more than the N54... makes me even more amazed that those things can take 600-700+whp day in day out. One would hope the N54 is at least that strong haha

not like the N54's cylinders are fully floating and free to move as they please at least

still, always excited to see where the platform finally lets go

i didn't check the thread.. but 6a12TT? from the VR4's/300gt? or an older motor pre-evo? interesting hearing history like that.

well yeah, the motor already runs hot, just imagine it with slightly worse cooling yet again?

pre-oil cooler days wouldn't only have seen motors limp mode, but likely totally blow.

The VR4 motor is a 6G72TT, And most acquisitions in this thread about them are false. They can handle quite a bit of boost on just fuel with no knock. The engines at one point has a bad history of knock related failures (most do to people tuning for knock alone).

And what Carl Morris said holds water and that is very recent news for the cars ecu thanks to monochrome.

[BOOST3D]

Its funny how people were saying the n54 wouldnt go past 400rw now thats the norm and people are making 700+ rwhp

[CPE-BMW]

Just wanted to dig this back out now that were at above 850 on stock internals..... wonder how far I can take it with next months release.

[thomas88162]

I imagine most of the reason for a closed deck design had to do with the large jump in compression ratio.

[Miller335]

Originally Posted by thomas88162

I imagine most of the reason for a closed deck design had to do with the large jump in compression ratio.

For NA or FI?

I would think a low compression FI setup pushing alot of boost would still have lots of cylinder pressure vs. a high compression NA setup.

[V8bait]

Closed has inherent advantages for strength. Open has inherent advantages for heat. With modern electronics, the advantages are nearly equal in the strength vs heat dissipation, as open allows for more average power via cooling efficiency at high temps, vs the heat sync closed deck allows for more error/detonation with heat management without failure.

This thread is old and you should feel bad.

[Miller335]

Originally Posted by V8bait

Closed has inherent advantages for strength. Open has inherent advantages for heat. With modern electronics, the advantages are nearly equal in the strength vs heat dissipation, as open allows for more average power via cooling efficiency at high temps, vs the heat sync closed deck allows for more error/detonation with heat management without failure.

This thread is old and you should feel bad.

While true for those of us who browse the site daily but joined in the last couple years it's a nice change of pace to see old threads like this.