I have main bearing issues so its time for another rebuild. I am looking for piston suggestions and any additional part suggestions while I have the engine out. I already have most of the goodies, (cam, header, head,) Is there something that is a MUST that I should look into?

 

Is this a track car? How many rebuilds have you done??? and who is doing them?
I'd talk to where some of your parts are from to get a complete package per se from them.. Instead of just buying up parts and throwing it together..

 

Its a daily driver. Ive done one rebuild and put high compression pistons in with methanol and I have never been able to make it run very good consistently. Plus it went through a quart of oil every few thousand miles and has metal shavings in the oil filter. I want the car to also be able to go with out methanol if I need to. I just want a good runner.

 

Sounds like you need to new engine builder.. and depending on who has messed with your head.. Lots more to a port and polish then just grinding out material... Alot depends on what kind of power your looking for..
Did you get it "tuned" afterwards? A stock R53 w/pulley and your cam and header, and the same guy tuning it you should have had about 215-220 HP ( no meth ) plus more depending on your " homebrew head work" ( assuming this isn't hurting HP ) As with anything it's all a matter of how much money do you want to spend!!
Don't think of meth as a power adder but a power maintainer... As everything gets hot it will help "maintain" the HP you do have..

 

I have Meth..only for cooling not tuning. If it's a daily driver I'd stick with stock Mahle pistons and put the money in a good head. I have TPR1 AND TPR2 and both run really well. I'd also check the condition of the block before spending much on pistons.

 

if its a daily driver with a M45 i would stay with stock ish compression
problem is the ECU hates the play ball with anything modified much.

 

Does mahle make a .5 over? My block has 12k since last bore, 80k total with the car, should be fine still.
I got these crumby pistons from a vender who recommended them. He probably didnt mean to cause me harm but I am done with tht particular vendor-

 

I'm not sure about that. Another member might chime in on that possibility. What's your budget?

 

I have mostly free labor cause I work at a shop so I can splurge a little. A couple grand maybe?

 

I dont think crumbly pistons have anything to do with the vendor, thats really indicative you have other issues than who sold the pistons to you.
Just buy a new stock short block is probably your best bet.

 

If you can make my 10:1 pistons run good with my stock ecu then let me know

 

I said earlier thats not really going to be a optimal situation.
If i were you I would just buy a new motor from mini, it might be cheaper and less hassle than you might think.

 

True, Luckily my best friend rebuilds engines and I paint cars. Just so happens he needs a car painted. Shooting for late december to tear her down. Im hoping just the rod bearings are bad and thats it. Still looking for piston options .5 over

 

I know you don't want to but I would call Jan at RMW, his new Arias Pistons are really quite excellent. and have been used on too many motors to count with 0 issues.

 

Colin, are weisco good/bad?

 

I personally have never used weisco so i really dont know, I know they are good quality in other things.
I also read that the CP had crumbling problems in the bmw market as well.
they use weisco and seem to have good results.

 

Wiesco ordered! new rod bearings, detroit tuned bypass valve (I remember liking mine) safety chain for tensioner, back to 15% detroit tuned pulley.... Anything else? Im a week away from tear down. Gonna try and keep the engine in the car. hoping the bearings will look good.