[O-cha]

Originally Posted by BaLLzZz

Whell the s54 is reaching limits of 1100 hp HPfed and supercharged. I know some internals are changed but not the block itself and that's an open deck. Im defiantly a newbie on the details but like many have said until a block or few get blown the real limits are still limitless!

Um since when is the s54 an open deck? S54s block is both closed and fully iron, it also has some very very good internals from the factory and one of the best if not THE best flowing production head ever.

You all need to realize that the N54 is never going to be a massive HP engine, it does GREAT in being a VERY cheaply (by bmw standards) modable to medium power level engine, with a low HP ceiling. It was not built to go to massive power levels, you want something like that buy a motorsport engine, period. They are built to take it, and will take it. S54 500 wheel all day "stage 2", the new v8 will be putting out 600-700 all day at "stage 1"

For reference here's the actual n54 block press photo:

The s54:

The new v8:

And the obviously similar v10:


They don't want to upload I'll fix it later

[SfValley335i]

Originally Posted by bdkevoIX

huh? if you're talking about e46 s54 inline-6, it is a closed deck cast iron block with aluminum head.

+1

[bdkevoIX]

Originally Posted by O-cha

You all need to realize that the N54 is never going to be a massive HP engine, it does GREAT in being a VERY cheaply (by bmw standards) modable to medium power level engine, with a low HP ceiling.

This puts whichever idiot that said 335i is THE next supra into shame

[BaLLzZz]

Like said I am a newbie but when the thread was originally started there was a picture of a s54 or supposedly s54 I6 with an open deck. And someone then corrected the OP and agreed that the picture was a s54 when indeed he wanted a N54. Sorry for the confusion guys, hope you do understand. Thanks for clearing all that up. And like some have said plain and simple when it comes to BMW if you want a hp monster buy a Motorsport engine they are designed and engineered for much of what can be thrown at it. As some old timers say BULLETPROOF!

To build on the thread the limit still has not been reached but with the turbo upgrades near who knows.

[O-cha]

Originally Posted by BaLLzZz

To build on the thread the limit still has not been reached but with the turbo upgrades near we are about to find out.

Fixed that for you.

[BaLLzZz]

Originally Posted by O-cha

Fixed that for you.

LOOl ahhah thanks!!!!! I do not think when I type sometimes.

[garyhgaryh]

Originally Posted by Dr_Dirt

So this supra block is obviously a closed type...

so is this Mitsubushi 3000GT VR4 motor but these still needed race gas to go over 16psi

Yup, the supra engines are closed deck (5m, 7m and 2j and probably even the 1j)...

[garyhgaryh]

Originally Posted by SfValley335i

Iron sleeves






Crap

Can you just replace the sleeve assembly or is the engine toast?

[alan93rsa]

If you want to see a true open deck take a look at a 944 engine. The cylinders do not touch period. The 944 S2 and 968 have siamesed cylinders, similar to what the OP posted as 'open deck'.

There was a general feeling in the 944 turbo high boost world that the cylinders could move and cause fretting on the head gasket which might lead to head gasket failure.

A good read on high hp from a 2.6 in line six may be found at:

http://www.ddurrelltech.com/pcar/exl..._944_600HP.pdf

Note that the sleeved 2.6 968 engine produces 600 hp at 24 psi! I think there is still room to go with the N54

There is also the mention of Bob Norwood's 900 hp Doom 944.

[Ninji]

Originally Posted by garyhgaryh

Can you just replace the sleeve assembly or is the engine toast?

Generally, the engine is toast. Aftermarket sleeving services use standard CNC programs to cut out the factory sleeves before pressing in the aftermarket sleeves. So when a sleeve is busted like that, the machine can't (easily) cut it away. Hence why most (if not all) sleeving companies require a core with unbroken sleeves.

And for what it's worth, the low r/s ratio means the N54 will have higher piston speeds and higher sidewall loading than an engine with a more preferable r/s. Basically, the rods are too short and the stroke is too long. It's a combination you usually see on economy engines. Performance engines usually have an r/s of at least 1.6:1, with 1.7:1 considered "ideal."

To be honest, this engine design is clearly not aimed at performance. The external goodies (turbos, vanos, direct ignition, direct injection) are what make it so powerful. People keep pushing the envelope and talking about turbo upgrades as though the engine has some sort of magical shortblock that can handle unlimited power, but I can tell you right now that engines are going to start blowing if people start shooting for 500whp+.

[Black Chili]

Originally Posted by Ninji

And for what it's worth, the low r/s ratio means the N54 will have higher piston speeds and higher sidewall loading than an engine with a more preferable r/s. Basically, the rods are too short and the stroke is too long. It's a combination you usually see on economy engines. Performance engines usually have an r/s of at least 1.6:1, with 1.7:1 considered "ideal."

To be honest, this engine design is clearly not aimed at performance. The external goodies (turbos, vanos, direct ignition, direct injection) are what make it so powerful. People keep pushing the envelope and talking about turbo upgrades as though the engine has some sort of magical shortblock that can handle unlimited power, but I can tell you right now that engines are going to start blowing if people start shooting for 500whp+.

Very well put. That explains one componant of the extra torque the BMW inlines are known for

Originally Posted by Ninja

you'll start to see "information" like this as pure nonsense that only serves to confuse and worry people who still view engines as magically complex mysteries.

That's exactly why I hit this thread again because i can't believe it's still going- I mean it makes zero practical difference at the moment. Every engine is vastly different. Convential understanding is that an NA motor is usually good for at least 30% more power than stock and i've never heard of a boosted motor good for anything less than a 50% margin. Your garden-variety Mustang GT block is good for 1300HP, the Ford GT block (a significantly redesigned and massivly beefed up, alum version of the F150 5.4L it's based on) is safe to 2000 HP (yes, look it up).

As the one of the few other knowledgible posters already mentioned, I've heard often of poorly tuned engines destroying itself at nearly stock levels and saw a stock '97 Cobra run 8 seconds before it blew up at 8800 rpm with about 26 pounds of boost (stock redline is like 6800).

I would also agree that i'd expect 500hp to be about the safe limit, but really who knows...????

[ar design]

Originally Posted by Ninji

And for what it's worth, the low r/s ratio means the N54 will have higher piston speeds and higher sidewall loading than an engine with a more preferable r/s. Basically, the rods are too short and the stroke is too long. It's a combination you usually see on economy engines. Performance engines usually have an r/s of at least 1.6:1, with 1.7:1 considered "ideal."

To be honest, this engine design is clearly not aimed at performance. The external goodies (turbos, vanos, direct ignition, direct injection) are what make it so powerful. People keep pushing the envelope and talking about turbo upgrades as though the engine has some sort of magical shortblock that can handle unlimited power, but I can tell you right now that engines are going to start blowing if people start shooting for 500whp+.

Hondas are making 800-1000hp with 1.5x rod ratios.

Nobody knows. At this point, absolutely everything is speculation. Period.

[McLuVan]

Originally Posted by ar design

Hondas are making 800-1000hp with 1.5x rod ratios.

Nobody knows. At this point, absolutely everything is speculation. Period.

true

we can all place our bets
mine is 450hp
the vq35de is an open block, aluminum etc and it's limit is 450hp without internal work
that's where I'll place my guesstimate

[edo]

Originally Posted by McLuVan

we can all place our bets
mine is 450hp

whp or at the crank?

[McLuVan]

Originally Posted by edo

whp or at the crank?

good Q..........
I say crank man
just to be on the safe side
450*1.12 = over 500bhp
haha

[edo]

Originally Posted by McLuVan

good Q..........
I say crank man

Well, then some folks here are already over the limit.

[O-cha]

Originally Posted by ar design

Hondas are making 800-1000hp with 1.5x rod ratios.

Nobody knows. At this point, absolutely everything is speculation. Period.

You speculating that it is speculation is speculation sir.

[Ninji]

Originally Posted by ar design

Hondas are making 800-1000hp with 1.5x rod ratios.

Nobody knows. At this point, absolutely everything is speculation. Period.

We're talking about factory shortblocks, not highly modified engines. Besides, the greatest engine series Honda ever designed (B16) had a 1.75 r/s. Many consider that ideal. The B18C line has a slightly worse ratio of 1.58. The bottom of the barrel econo motors (i.e. d-series) had a 1.5 r/s.

Good for low end torque, bad for high revs. The only reason Honda people (i.e. me) are able to extract so much power is by using beefy parts and keeping super tight tolerances. Still, the engines that make the power the most easily/safely/reliably are the B16 motors with the good r/s.

This isn't speculation so much as common sense. Open deck with a low r/s is bad news. Hondas make power despite this shortcoming, by pouring obscene amounts of money and work into the engines. The specific engine I have in my Honda (with the open deck and 1.52 r/s) starts throwing rods at almost exactly 2x the factory power output with an unmodified shortblock.

Applying the same 200% safety factor to the N54, I'm guessing that the engine will give out at 550whp. So I guess maybe it is just speculation, but it's educated speculation!

[McLuVan]

Originally Posted by edo

Well, then some folks here are already over the limit.

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

[McLuVan]

Originally Posted by Ninji

We're talking about factory shortblocks, not highly modified engines. Besides, the greatest engine series Honda ever designed (B16) had a 1.75 r/s. Many consider that ideal. The B18C line has a slightly worse ratio of 1.58. The bottom of the barrel econo motors (i.e. d-series) had a 1.5 r/s.

Good for low end torque, bad for high revs. The only reason Honda people (i.e. me) are able to extract so much power is by using beefy parts and keeping super tight tolerances. Still, the engines that make the power the most easily/safely/reliably are the B16 motors with the good r/s.

This isn't speculation so much as common sense. Open deck with a low r/s is bad news. Hondas make power despite this shortcoming, by pouring obscene amounts of money and work into the engines. The specific engine I have in my Honda (with the open deck and 1.52 r/s) starts throwing rods at almost exactly 2x the factory power output with an unmodified shortblock.

Applying the same 200% safety factor to the N54, I'm guessing that the engine will give out at 550whp. So I guess maybe it is just speculation, but it's educated speculation!

but the n54 has vanos, direct injection system, and etc
more possible limiting factors

[Turkishexpress]

Originally Posted by McLuVan

but the n54 has vanos, direct injection system, and etc
more possible limiting factors

Actually honda heads are notorious for their flow efficiencies so we really have the DI to depend on

[aedan]

agreed, if you were knocking on 93 at 16psi there was something else wrong with the car. My 95vr4 makes 600+ awhp on the DR800's (3000gt guys should know DR ) with 0 knock at all on the stock bottom end. Even before i did the heads and was running the entry level DR turbos with the bone stock tune i had no knock on 91 gas (in vegas) and that was 18-20psi.

Originally Posted by bdkevoIX

It's called poor tune and idiot tuners who called themselves tuners and even more idiots who run their cars with apparent knocks.
Deck design has nothing to do with prevention of knock.
You could blow a supra motor just as easy with a poor tune.

And its not for determining boost limits. It's more like how much power the motor can hold. Take 2jz-gte, rb26dett, and 4g63 for example, these closed deck engines make more than 250whp PER cylinder or 500whp PER liter of displacement when built right. Just think of the extreme cylinder pressure when one cylinder is making excess of 250whp. It's obvious to me closed deck will be more sturdy to this kind of "extreme" pressure than an open deck.

This doesn't apply to most guys who are pushing ~400whp. And frankly I wouldn't worry about deck design until I'm past 500whp mark on 3.0L motor.