[edo]

Hi, guys,

It‘s been a long time since I‘ve been here.

I have a tuned E92 335i N54:
1. RB turbos (first gen.),
2. Piggyback
3. DCI
4. Scoops
5. DVs
6. fully c/l exhaust system
7. FMIC
8. LSD
9. Oil Cooler Kit
10. Coilovers

I bought some more mods 2 years ago, but all of them have been lying in the box in my garage, since I almost don‘t drive my BMW... Here‘s the list:
1. Stage 2 Bucketless LPFP
2. Charge pipe Upgrade Kit
3. Clutch delay valve
4. PCV valve
5. OCC
6. Silicone inlets

So I decided to install the remaining parts and was recommended one guy who specializes in tuning BMWs and N54 engines particularly. We agreed on everything, but he told me that N54 engines had one weak area – connecting rods. According to him, the rods can hardly withstand even a slightly increased power (e.g. reflash/piggyback only). He claimed he even had some stock N54s in his garage with bent/ripped connecting rods. Everything else is quite reliable, according to him.

This was quite a surprise for me, as I’ve never heard of someone with engine failures due to connecting rods, while there are thousands of tuned N54s out there, some of them – really heavily. I googled a bit and found some topics regarding bent rods and holes in the block.

Changing connecting rods means at least ~2.5-3k Eur (parts + labour), therefore, I would definitely avoid getting into the internals, unless this is really necessary. Also important thing - my engine is quite new, I had a failure and changed the whole engine, drove ~20K km.

Is this true regarding bending/ripping connecting rods? :shrug Would you upgrade it? Please share your thoughts/experience/knowledge.

Thanks in advance.

BR
edo

[type-dRew]

If he can install your parts competently, cool. But I wouldn't let him tune your car or go any further.

Just install your parts. You don't need rods.

[edo]

Originally Posted by type-dRew

You don't need rods.

Can you please elaborate?

[type-dRew]

Originally Posted by edo

Can you please elaborate?

Don't pay someone to put new connecting rods in your engine.

[hellokitty]

Yeah rods are not needed.

[edo]

Guys, do you have something to support your suggestions?

There is a number of topics regarding bent rods, when you google. Some of the cars are not that heavily modified. This is the reason I am on the fence now: on one hand, I don't want to disassemble a new engine (20k km) and pay 1.6K Eur for rods + labour, on the other hand, I don't want a hole in my new engines block...

[hellokitty]

Originally Posted by edo

Guys, do you have something to support your suggestions?

There is a number of topics regarding bent rods, when you google. Some of the cars are not that heavily modified. This is the reason I am on the fence now: on one hand, I don't want to disassemble a new engine (20k km) and pay 1.6K Eur for rods + labour, on the other hand, I don't want a hole in my new engines block...

Stock block is pretty solid up to 600 whp. Once you go past that, you should consider building the motor. See below.

https://mmp-e.com/products/n54-built-engine-program

[type-dRew]

I dont see port fuel on your list so i'm doubtful you'll be anywhere near a power level that requires rods.

You're asking me for a burden of proof when i'm trying to help out. Sorry, feel free to come to your own conclusion. I don't care if you spend your money on this, i'm just saying, as a random person over the internet, you don't have to.

Do with this opinion what you will

[JBacon335]

If you somehow bend a rod it is either from requesting excessive boost below 3500 rpm or you hydro locked it. there are plenty of builds throwing down 700+ at the wheels on stock internals that don't have an issue

[TemjinX2]

the engine should be good till 600whp....people started having engine issues after 600whp or from bad tunes.

[Jklad]

At this point I would consider another tuner.

If he "tunes" n54s, and then says that they bend rods all the time, when bending rods isn't a common issue on this platform, I'd go somewhere else and may not trust him to tune or work on my car.

[IllSic_Design]

I am FBO and Ethanol pushing 430whp on a stock block at 184k miles. You don't need rods.

[TemjinX2]

there seems to be a divergence between the old school BMW tuners/mechanics and the N54-B58 mechanics/tuners

Kinda like analog vs digital type thinking.

The N54 was the first mass produced turbo motor for the US market for BMW, so they took many steps in making it as strong as possible within reason.

If your in europe, i would contact MHD and ask what tuners they normally work with in your country.

[blown07]

Originally Posted by IllSic_Design

I am FBO and Ethanol pushing 430whp on a stock block at 184k miles. You don't need rods.

Nice but your car doesn't have scoops. This mod has likely pushed his car to the ragged edge of connecting rod strength.

[srey]

Originally Posted by blown07

Nice but your car doesn't have scoops. This mod has likely pushed his car to the ragged edge of connecting rod strength.

That's savage, lol.

OP, your tuner is just trying to sell you something. If he is telling the truth, and cars with thrown rods are in his shop, then it's likely an issue with his tune. If not, he's just feeding you a line to motivate you to upgrade your rods. Even giving him the benefit of the doubt, it's a pretty cautious move at your power levels, IMO.

[tisdrew]

Fuck that guy, never go back to him, he clearly just fed you a line of bullshit. The crank and conrods for the n54 07-10 are forged and are good up til and past 600whp.

No offense, you clearly need to do more of your own reading on the subject.

[bbnks2]

Originally Posted by TemjinX2

there seems to be a divergence between the old school BMW tuners/mechanics and the N54-B58 mechanics/tuners

Kinda like analog vs digital type thinking.

The N54 was the first mass produced turbo motor for the US market for BMW, so they took many steps in making it as strong as possible within reason.

If your in europe, i would contact MHD and ask what tuners they normally work with in your country.

Actually, pretty much every "M" motor BMW has ever built is stronger than an N54 LOL

People stating that BMW intentionally over-engineered the N54 are pulling that statement out of their ass. There is noting special about the N54. It's actually fairly weak, and has some major flaws, in comparison to some of the other blocks that BMW has built. The S54 has made 1000whp+ on the stock block. Max any N54 has done is 83xwhp... and then those N54s all blew up within days of doing those pulls LOL Spun crank hubs, cracked pistons, bent rods, etc.

These engines are pretty stout up to 600whp if the tune is good. That does not mean that making 600whp+ on a stock block is a good idea. Any competent engine builder will tell you to build the block if you do any kind of performance driving. Stock internals and clearances are designed for efficiency at 300whp that's just facts.

[TemjinX2]

Originally Posted by bbnks2

Actually, pretty much every "M" motor BMW has ever built is stronger than an N54 LOL

People stating that BMW intentionally over-engineered the N54 are pulling that statement out of their ass. There is noting special about the N54. It's actually fairly weak, and has some major flaws, in comparison to some of the other blocks that BMW has built. The S54 has made 1000whp+ on the stock block. Max any N54 has done is 83xwhp... and then those N54s all blew up within days of doing those pulls LOL Spun crank hubs, cracked pistons, bent rods, etc.

These engines are pretty stout up to 600whp if the tune is good. That does not mean that making 600whp+ on a stock block is a good idea. Any competent engine builder will tell you to build the block if you do any kind of performance driving. Stock internals and clearances are designed for efficiency at 300whp that's just facts.

Say that to the e46 m3, e92 m3 and e60 m5 guys with their rod bearing issues. i'd rather deal with leaky injectors and HPFP then rod bearing issues.

your info on the N54 is 3yrs out of date....motiv already has a 1056whp N54.

Read up on the modifications BMW on the short block of the N54 compared to the N52. Also BMW had to build the N54 to a cost stand point, so their are limits on what they can and cannot put in since it was a mass market engine. There are not a lot other engines out there that can compare to it in 2006 in a sub 45k car.

[bbnks2]

Originally Posted by TemjinX2

Say that to the e46 m3, e92 m3 and e60 m5 guys with their rod bearing issues. i'd rather deal with leaky injectors and HPFP then rod bearing issues.

your info on the N54 is 3yrs out of date....motiv already has a 1056whp N54.

Read up on the modifications BMW on the short block of the N54 compared to the N52. Also BMW had to build the N54 to a cost stand point, so their are limits on what they can and cannot put in since it was a mass market engine. There are not a lot other engines out there that can compare to it in 2006 in a sub 45k car.

I said stock block record is 83xwhp. The most recent stock block N54 to hit 83xwhp blew up on its 3rd pass ever down a drag strip. Shattered a piston and threw a rod out the block.

Motiv made 98Xwhp on a properly corrected plot (with smoothing). No one has actually made a legit 1000whp yet. Humps in uncorrected graphs don't count in my opinion. I guess if you're rounding up then yeah sure they kissed 1000whp lol. The Motiv engine was completely built though from having a closed deck to a ported cylinder head. Probably $15K in work for us peons. A far cry from a "stock block." And again it was out of action a few weeks later when they spun the crank hub making a pass at a 1/2 mile event.

I am talking about things way beyond injector and HPFP issues. N54 is a tight tolerance engine with an open deck block and a two-piece failure prone crankshaft. Pistons are cast and rings can't take much long-term abuse past 600whp. The cylinder head is restrictive. These are just facts whether you want to accept it or not.

Comparing the N54 to the N52 as an example of how "over-engineered" it is makes no sense. Sure, BMW put in some larger diameter bolts throughout the N54 block to handle boost but that's about it. That does make it a stout block capable of some damn good numbers in stock form. Compare it to any actual performance motor from BMW though...

The point isn't to bash the N54 but to bring awareness to the reality of what it is lol. Like you said, it's a cookie cutter engine designed around making an efficient 300whp.

Oh and rod bearing failures? N54 is just as likely to have rod bearing wear... Was it Turner? Or Motiv? I forget who but one of the vendors pulled N54 bearings at 60k miles and showed significant wear. There are plenty of failure threads to reference too, unfortunately.

[dublin14]

There.are lots of guys with 700bhp n54s running for years now.

[TemjinX2]

Originally Posted by bbnks2

I said stock block record is 83xwhp. The most recent stock block N54 to hit 83xwhp blew up on its 3rd pass ever down a drag strip. Shattered a piston and threw a rod out the block.

Motiv made 98Xwhp on a properly corrected plot (with smoothing). No one has actually made a legit 1000whp yet. Humps in uncorrected graphs don't count in my opinion. I guess if you're rounding up then yeah sure they kissed 1000whp lol. The Motiv engine was completely built though from having a closed deck to a ported cylinder head. Probably $15K in work for us peons. A far cry from a "stock block." And again it was out of action a few weeks later when they spun the crank hub making a pass at a 1/2 mile event.

I am talking about things way beyond injector and HPFP issues. N54 is a tight tolerance engine with an open deck block and a two-piece failure prone crankshaft. Pistons are cast and rings can't take much long-term abuse past 600whp. The cylinder head is restrictive. These are just facts whether you want to accept it or not.

Comparing the N54 to the N52 as an example of how "over-engineered" it is makes no sense. Sure, BMW put in some larger diameter bolts throughout the N54 block to handle boost but that's about it. That does make it a stout block capable of some damn good numbers in stock form. Compare it to any actual performance motor from BMW though...

The point isn't to bash the N54 but to bring awareness to the reality of what it is lol. Like you said, it's a cookie cutter engine designed around making an efficient 300whp.

Oh and rod bearing failures? N54 is just as likely to have rod bearing wear... Was it Turner? Or Motiv? I forget who but one of the vendors pulled N54 bearings at 60k miles and showed significant wear. There are plenty of failure threads to reference too, unfortunately.

I dunno where your getting your info from on the N54 rod bearings, but there a lot more cases of rod bearing failures on on S54's, S65 and even N55s compared to N54's.

Also the N54 is designed to be 300hp crank motor in a sub 45k car. You said it yourself someone got 83xwhp on a stock n54 block and your saying its not over engineered from the factory?

going from a 300hp crank to basically a 900hp crank on a stock block seems pretty impressive to me, especially since this was a mass market engine that was essentially a modified N52 motor.

Keep in mind its a lot more difficult to design a hp power engine for a sub 45k car then a 60k+ car, especially for a small manufacturer like BMW. GM does a excellent job with their LS motors but they also have larger economies of scale to spread out costs.

[edo]

Thanks a lot for your input, guys. I decided not to build the motor. Especially keeping in mind that the car is already 12 years old...

Regarding N54 vs S65 egines.
Well, both are definitely not perfect. I have blown my moderately tuned engine (tune, intake, downpipes, fmic) in 2009 (the thread) that was 2 years and ~15k miles old. That was a factory defect.

Then a friend of minde blew his stock E92 M3's engine (I was filming the race) because of a rod bearing failure:

the thread