S50 Is dead thanks to TRM.

[dinanm3atl]

What a fun thread :)

[EtaSport]

Well it appears that it has been settled and OP got what he was looking for. It is a true shame that you had bad luck with your engine. I know what its like, my machinest cut my bores for forged pistons and increased cold piston to wall clearance on my maxsil pistons which causes slap for a few minutes with cold ambient temps, not something I enjoy for an $3k engine that will see regular track conditions.

So yes it sucks, but we can move forward now.

[Massive Lee]

I know what its like, my machinest cut my bores for forged pistons and increased cold piston to wall clearance on my maxsil pistons which causes slap for a few minutes with cold ambient temps, not something I enjoy for an $3k engine that will see regular track conditions

And your machinist was 100% right. Those forged pistons have more expansion than you think. Therefore the bores need to be oversized so that the fit is right when warm. If he did the engine tight when cold, well, the pistons would get stuck when hot. I hope you didn't give him shit...

My Euro 1979 635 had a 4 litre Metric Mechanic motor with their forged pistons, and there was also a bit of piston slap when cold. Perfectly normal.

BTW: what's the biggest rotor you can fit under a 17 With the wilwood 4 pot lights?

13" with Superlight

[Stu]

And your machinist was 100% right. Those forged pistons have more expansion than you think. Therefore the bores need to be oversized so that the fit is right when warm. If he did the engine tight when cold, well, the pistons would get stuck when hot. I hope you didn't give him shit...

My Euro 1979 635 had a 4 litre Metric Mechanic motor with their forged pistons, and there was also a bit of piston slap when cold. Perfectly normal.



13" with Superlight

Right on, the machinist made no mistake. I distinctly remember the sound of M10's and M20's Pete used to build in the early/mid 90's with forged pistons -- lots of slap when cold.

[EtaSport]

Maxsil pistons are not forged to my knowledge (casting marks are visable on the underside of the piston) and require a tighter piston to wall clearance due to the high silicone content, it was stated on a card I received with the pistons and I passed the info to my builder and this was my result. I know that it is normal on a forged motor.

"MaxSil™ Pistons are lighter and stronger than original BMW pistons with 13% silicone content allowing for tighter cylinder clearance (0.0015"). The reduced heat expansion and anti-friction properties offer better performance and longevity than original BMW pistons while protecting horsepower output for the life of the engine."

I guess the point of my rant (in relevance to the thread) is given the above info I still dont worry about the piston slap and I still recommend my machine shop.

[M3 euro ltw]

Lemme guess...

Don't worry. I am not angry at all. In fact I am laughing out loud, and rolling on the floor. This thread is giving me such a grin. You got no idea. I just can't wait for the TRM reply.

Honestly, just between you and I, nobody's around us to listen, do you really think TRM is to blame for your problems? Come closer, you can whisper in my ear...:pimp:

Tony Aaron to Angeline..... awesome.....I wonder how many people caught it?

Well done...not just BBK, but movie trivia extraordinaire...

(I've got it on Laserdisk believe it or not)

[FredK]

Maxsil are definitely cast, and are great replacement pistons, as they avoid the additional clearancing you need with forged pistons that can cause slap.

The one thing I don't like about them is that they're only available in 2nd oversize. No more boring.

[EtaSport]

I had placed an order for +.5mm weisco pistons in 11:1 and waited for the 5 week build time just to get a call that they were never ordered, so I bought the maxsil pistons cause they were "off the shelf" All maxsils are in a +1mm or 0.040" so you'd have to overbore which will take an s50 to 87mm.

If you want higher compression id get a JE or weisco since they can be had for about the same price as the maxsil. At least you get rings with them which eliminates the costly factory s50 ring replacement.

[nando]

have you pulled the bearing caps to look at the crank yet?

BMW cranks are pretty tough. you may get lucky and all that you'll need is a polish and new bearings. and maybe a rering/hone..

BTW, my forged MM pistons don't slap on startup :p

[Massive Lee]

13 is just not that much bigger than the e36 M3 fronts to be worth the trouble for me. I am Sure the pedal feel is nice though.

13" is not much bigger, indeed, but some 13" discs are 1.25" thick (32mm) which is much thicker than stock e36 M3, and offers more cooling and more resistance to heat stress. Pedal feel is also one of the advantages of the forged Superlites.

Lee

[Stu]

I had placed an order for +.5mm weisco pistons in 11:1 and waited for the 5 week build time just to get a call that they were never ordered, so I bought the maxsil pistons cause they were "off the shelf" All maxsils are in a +1mm or 0.040" so you'd have to overbore which will take an s50 to 87mm.

If you want higher compression id get a JE or weisco since they can be had for about the same price as the maxsil. At least you get rings with them which eliminates the costly factory s50 ring replacement.

I spoke too soon, sorry.

87mm, is that what folks are doing these days?

[EtaSport]

I tell you Stu I was a little apprehensive boring to 87mm but it worked out well, I needed at least a .5mm overbore to use my block, and I figured if the s52 works with an 86.4 it should be okay.

[jrhaile]

Why would you drive it knowing you had a fueling problem at high rpm and not try to figure out?

OP.. same question I had after reading a bit more. Seems crazy dude.. again, best of luck.

[rneedham1979]

Interesting info quoted below.

Cat size has nothing to do with smoking or noticing smoke, you, yourself mentioned you had plenty of smoke on start up so, if your theory is correct, why didn't your cat hide the start up smoke you referred to earlier?

Having a large cat has nothing to do with you not seeing a rich condition. First off cats need to be at operating temp before they work efficiently. Second cats do not stop excessive fuel. They help strip pollutants out of exhaust in a properly running vehicle. You would have seen a rich condition with or without your large cat. For instance in FI cars, with cats you will physically see a rich condition (black smoke) coming from the tail pipes at anything below 11.5's. Your car had to be way richer if it filled your oil pan with fuel and ruin your engine.

You did not see smoke either because you weren't rich or you weren't looking. Even with a huge cat and you will still be rich and still notice black smoke, the size of your cat has little relevance here, especially when you are saying "the tune" commanded X amount of fuel, which ultimately ruined your engine.

If the tune was bad and poured enough fuel into your engine to ruin it, black smoke, rough running and the smell of fuel would have been more than noticeable. This cannot be disputed or denied!

I also find it amazing this chip worked in three different cars, what's the ECU numbers for the three cars? I highly doubt they were all the same box, which will HIGHLY effect the way the car would run.

Again, can you post pictures? You are calling a well known tuner out and you have not provide pictures, I would like to see pictures of the one new injector, the old injector, oil and I would love to see a video of the tuner/TRM chip comparison... A video would be an easy way to prove all of us wrong. Pictures speak 1k words...

Lastly, if you cannot say with 100% certainty, you should have never posted this thread with hopes of discrediting a known tuner.

I am also under the opinion that my car never bellowed black smoke that I could see as I am running a big cat.
Can I say with 100% cert. that the chip did all of the damage,no. Can I say that in my opinion it contributed to the situation or likely caused it, yes.

[gazellebeigem3]

Wow about all I can say i am 100% certain of is that you think I have far more free ti e than I actually do. The engine is out but I have not been able to disassemble it as I have a job and a life away from my car and before anyone says "well if you are so sure why wait" I will say that the engine can and will wait because I won't ignore my wife and infant daughter to tear an engine apart. I will take it apart in my own time. I returned the injector to napa because I do not need it and as a matter of fact I am so paranoid about overfueling that I am going with 21.5's withmy new turner chip. The engine is torn apart so I can't run either chip in my car and my friends in the area who ran the chip for a few min don't want to run it again after seeing how terribly it ran. I did my brake in and diagnostics on the freeway at low rpm and I saw no visable smoke @65 mph. I love how sure everyone can be that I am wrong an they are right when I am the one withthe dead engine. If someone has the balls and wants to meet me I willbe happy to put my chip in your car and shoot a video.

The only thing that im 100% certain about is that you look like a halfwit and you shouldnt have ever started this thread. I also would like to throw up the bs flag on you having any ase certs other than brakes and suspension.