Mild Cam Grind M20B20

[tibbs.james 1]

Hello Dudes

First question is about having a bmw camshaft ground.

i know with most jap cams they can quite sucessfully regind and harden the surface with good result and that providing you use surfaced lifters it will work very well.

that was the case with an old toyota 4k engine i built for a mate anyway (high compression bigger valves hot cam spings and shims with big webber carb )

since bmw have diffierent ways of doing things can this be done without excessive camshaft wear?

I am only thinking about a mild gind to improve things. a bit more go and a retune with an airflow meter correcter box would be great.

Since a decent panel filter is about as good a pod filter there can't be reasonable gains to be made here.

And my head casting was very smooth in all the ports so it made no sense to do any work there.

I wouldn't be looking at running stiffer springs as increase in duration and lift would ideally not be enough to need it.

not to hammer on too long but what is the standard duration and lift for a FL m20b20 cam?

any help appreciated

James

Edited September 9, 2007 by Jimmy

[pureboiracer 0]

you can regrind the cam at a place called calford cams in chch. not sure how much. however they dont advise that you do it because of the hardend surface on the cam and it could cause the cam to fail. if i were you i would just buy a new one or get one made from a new billet. i got a 304 degree cam with double the lift of the standard one from the states and worked out to be not much more expensive than regrinding one

[Andrew 30]

you can regrind the cam at a place called calford cams in chch. not sure how much. however they dont advise that you do it because of the hardend surface on the cam and it could cause the cam to fail. if i were you i would just buy a new one or get one made from a new billet. i got a 304 degree cam with double the lift of the standard one from the states and worked out to be not much more expensive than regrinding one

I too have the 304 cam in a dedicated race car motor - do NOT rev your motor over 6500 with the stock rockers and valve springs - you will get bad valve float.

[Gus 5]

why bother? seriously? by the time you have paid for everything you could have afforded a 2.5 (or near enough) which obviously is a much better result

[tibbs.james 1]

Well Reason i ask is

My M20 cylinder head ,water pump cam belt ect has alreadby been rebuilt/replaced. I was thinking if there was a not so aggressive grind that gave a general imrprovement without massive lift or anything it might be a good idea. especially if the grind was only $150 or so.

If i buy a 2.5 i will end up rebuilding the whole thing which means buying all the same stuff all over again for a diffierent engine.

When kelfords did that cam for the 4k engine it was $400 for the grind isself, lifters to be surfaced and included valve springs & shims.

you might say yes a B25 might be $400 or $500 but then you don't really know what you are getting. and i would still need a FL motorinic 2.5 ECU .

It was just a thought now i have brought togates eibach springs i better buy some decent dampers now !

[wms 1]

Look around - I found a Schrick 290 for my M30 with all valve springs NOS for next to nothing