anybody know were i can get a crank re-ground and balanced for a 20vt properly

any F.E.R registered engine remanufacturer would be able to do this

cheers

some of them get a bit confused when ballancing them though, just make sure they know its not a v5

will do thanks again

the coupe cranks dont like a regrind due to the nitriding which gets removed when ground causing premature wear there a f.aq on here i think

I am pretty sure that is only the 16 valve cranks. Although I may be wrong.

No, its also the 20v.
But you can get it nitridid again - i did, and it works like a charm!

the nitriding would done to a thickness, e.g. 0.6mm, as long as you do not remove to much of the nitriding then you will be fine

You need to find out how thick the nitriding is before you do anything

I personally would just get a good second hand crank, the cost of nirtriding and grinding a crank would probably be more expensive than replacing the crank

Any grinding will remove all the nitriding. Keep in mind most cranks are not nitrided in the first place and they get along fine. If you are building a race engine or something highly stressed its not a good idea but for any average engine it will be fine.

Really??!!??

Yeah - although they called it something else (danish word, and i dont know what it translates to), but its the same treatment that the Le Mans Audi R8 TDi engine gets done. Actually the same guy that does Audi's did mine

BMW also needs a re-nitride treatment when regrinded. Oh and the 20v workshop manual also describes that a re-nitride treatment is required after a regrind.

I was under the impression that you could only plasma nitrite when the crank is actually made as a heat treatment. It can be re-applied afterwards but doesn’t actually do anything as it is not gone deep into the material. Can anyone confirm this?

Thats the way I understand it, surely a new or good crank is a better option.

AFAIK re-nitriding a crank is very difficult and expensive.

im not convinced they are nitrided in the first place

They ARE nitride hardened - it says so in the workshop manual.