newbie here.

[pablo-e30]

hows it going. found this site from a link from e30tech and i hope ppl on here can help me out, going to turbo my Is and i need some help. i have tried to source m3 pistons for the stroker but i can't get any at a decent price, is there any companies out there how make pistons that can also be used or can you use the pistons out for a s14 m3 engine? cheers for looking

[Febi Guibo]

I had my pistons made at wiseco... you should maybe check them out?

[pablo-e30]

i founf a site selling je pistons for the m42, could you use these as a part of a stroker with a m47 crank and turbo as you can get low comp?
heres the link http://www.racetep.com/jeimport.html#bmw

[FL318is]

Glad to have you here. Great site, lotta good people. I found that if you ask a question here, you wil get the answer.

[Febi Guibo]

The M47 crank has a stroke of about 88mm... there's a combination of rods / pistons that will work for your project. Having said that... the stock M42 crank is pretty decent, and the rods are forged.

If you are going forced induction, maybe consider only using custom pistons and balancing the rest of the internals?

[pablo-e30]

cheers, you were saying that the m47 crank was used in rovers, i live in ireland so therte is s**t loads of them about, do u no which rovers they came in? and also don't no much bout all this piston size lack, so can some pleaes help me out with wat size of piston i'd need to get the 2.1 stroker? cheers so far ppl

[Febi Guibo]

The M47 crank was new from BMW... you want the one that came from an E46 320d I think.

I would recommend using a new crank; diesel cranks have a tough life; I'm not sure if the Rover crank will work as easily as the M47 crank; this was pointed out to me by tim_s (who is in england --we don't have rover cars here in the US) I think knows more about it.

photos of the crank I used and other bits (note, I wound up using lighter I-beam instead of the H-beam rods pictured) are here:

http://m42club.com/forums/showthread.php?t=254&

[pablo-e30]

just looking through ebay there and was wondering would these be good for a turbo engine and m47 crank? the pistons are 85.485mm and a 0.50mm over sized
http://cgi.ebay.com/ebaymotors/1996-to-1999-BMW-318i-M44-Piston-kit_W0QQcmdZViewItemQQcategoryZ33623QQihZ019QQitem Z8071202084

[Febi Guibo]

...would not recommend bavarian engine exchange...

[pablo-e30]

cheers for the advice thought the price was to good to be true. going to go for custom pistons or s52 what ever comes up first, wat would be good compression ratio on a custom piston to get from a same bore as a s52 for a turbo egnie. not going for a crank as i priced a few and its not worth my while getting one. just going to balance the internals in her.

[Febi Guibo]

there are a couple of guys here (2002maniac and... ?) who are building high compression M42 engines with S50 pistons, stock crank and I believe stock rods...

for a turbo, in my non-turbo education opinion, you'd want lower compression... a lot lower. maybe custom rods?

[dino245]

M44 crank (83.5mm strock)
S52 Pistons (86.4mm bore)
stock rods

The M44 crank is not that bad and its a cheap way of getting a few mm of stroke with out getting the infamous M47 crank that is on the other side of the pond. I chose to keep the stock short so that the rod ratio is not disturbed too much and the "revability" of the M42 is not lost. Also the M44 is known to produce over 200hp with a supercharger so an NA application putting out 175 wont be too hard and still maintain the reliability. The M44 crank does only have 4 counter weights and is cast. The crank weighs 29lbs and I assume is lighter than the M42 crank which will aid in a faster accelerating engine.

All of this is theory for the time being until either 2002maniac or I finish our engines.

Just remember there is always a way to through vast amounts of money at a car, but its still an old car that you will never get a dime out of. And there sill always be some other car faster,corner better and just plain kick your A** so plan of a happy medium.
Good balance is the holy grail.

[pablo-e30]

sent a quote form of to je pistons for 86.4mm bore and a compression of 9:1 for the m42 crank, just have to wait on a reply, but i'll look into the m44 crank, cheers for the help sp far