Raise your hand if you've blown up an N54!
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Hey Tony, it seems to me that you get more bang for your buck if you upgrade to forged pistons, sings, connecting rods and it's not really crucial to get a closed deck if you are aiming only for 700whp? Or am I wrong?
I think this is possibly a case of confirmation bias. Kind of like when you get a new car, you start seeing every example of that car. There are things that are absolutely terrible and common on N54s - MSD80 mosfets, injectors, even waterpumps, etc. Bearings are not typical, but you will definitely find the case here and there. It is an engine after all, and the e90 3 series was one of the highest selling BMWs ever, so you're bound to find examples. A think spun hubs are more common than spun bearings, but very few people have spun the crank hub. It just gets talked about more since it happens at high power levels and there is very little or affordable that can be done about it.
I also see a lot of people bragging about their $4,500 cars which they are beating the ever-living out of. Maintenance matters more than anything. And that includes, the awareness of having an issue and needing maintenance.
A friend recently bought an inexpensive E90 (twice the above price, though) with over 100k miles. Lots of maintenance. When I took a few things apart, plenty of oil and dirt in the engine compartment, lots of missing hardware (like holding down the cowl assembly), JB Weld holding together the upper radiator snout, extra parts in the top shock tower perch, et cetera. And it had maintenance records. When a car gets to be 10+ years old, and has performance, it can often have 3-4 owners. One becomes an automotive archeologist. For whatever maintenance it may have, lots of hands have often touched it by 100+k. Of course there are cream puffs, but nonetheless I think my experience with this particular E90 is hardly uncommon.
Filippo
A friend recently bought an inexpensive E90 (twice the above price, though) with over 100k miles. Lots of maintenance. When I took a few things apart, plenty of oil and dirt in the engine compartment, lots of missing hardware (like holding down the cowl assembly), JB Weld holding together the upper radiator snout, extra parts in the top shock tower perch, et cetera. And it had maintenance records. When a car gets to be 10+ years old, and has performance, it can often have 3-4 owners. One becomes an automotive archeologist. For whatever maintenance it may have, lots of hands have often touched it by 100+k. Of course there are cream puffs, but nonetheless I think my experience with this particular E90 is hardly uncommon.
Filippo
That's why with me I'd rather buy I higher mileage single owner car then lower mileage multiple. Especially cause usually if car has seen alot of owners it may be a lemon and if you ask everyone will just blame previous owners for any issues
Not to digress, @Rob09msport, but yeah ... the reasoning is ... whatever is easiest to discern lineage-wise. The more I know about a car the better. The older it is, the harder that generally gets. A three owner car with records is better than a 1-owner car with no records. A specialty car in some ways is easier to buy - the N54 cars are all pedestrian rides. As they get older, many become cheap-ass sport sedans for people without money / car knowledge / take-your-pick.
My Z4 will be a bargain for someone, one day. It has sat most of its life with me apart. I've only clocked 7k miles in the last 3 years (aaaaargh).
Filippo
My Z4 will be a bargain for someone, one day. It has sat most of its life with me apart. I've only clocked 7k miles in the last 3 years (aaaaargh).
Filippo
I seriously thought I was the only one. I hit around 700 to 1k miles a year in a good year. the last 2 years probably 1300 miles total.
I am thinking the same thing. Forged pistons and upgraded rods seem to be crucial. Would be nice to avoid the inserts or the cost of sleeves if not going above 700. 700 and below seems to be a nice place for most of us for many reasons.
Honestly half the time has been my project work, but the other half has been 3rd party products that have failures, and trying to deal with that.
Filippo
While that's true when looking at specific rods as examples, that's not correct when fundamentally looking at the design.
Here's the thing... close decks eliminate the open spaces the the stock coolant flows through. So you in theory have more heat, more knock...the question is - is that a worth while trade off? Vs. Just jeeping open deck and upgrading piston, rings, rods and all bearings?
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I don't know too much about engines but I'd be worried about the cylinders ovaling over time and losing compression.
Also the head lifting off. So sleeves and head studs would be on my list.
FWIW 4B11 blocks are open deck, yet can be made to handle >250whp per cyl when built right and sleeved. By comparison, the most powerful N54 out there is yet to crack 160whp/cyl...
Forgot about the head studs. Sleeves reinforce the cylinder walls without closing deck? Seems like a no brainer then?
All I'm saying is that its not strictly necessary, and that there are several ways to skin the proverbial cat...
I would word the question differently. Or I just think this question makes zero sense.
Back in the real world, failures often happen when everything doesn't work 110% right. It's a grey line. So design approach deals with the myriad of variances - material composition deviations, design deviations, assembly deviations, and the 1,000's of different real-world environment variances that make things not work like textbook fantasy land.
A built motor is just as much an exercise in insurance against everything that one can think of which can go off script (and all the stuff one can't think of) as it is trying to hit a magic number like 960whp.
Filippo
That 960 values is based on 160 per cylinder as stated by the comment previous. Nothing to do with what I plan. Insurance for my power levels would be pistons, ring, rods, bearings without closed deck or sleeves. Because I only want 700 max and realistically 650... nowhere near 960 at all.
