BMW 16V Head Conversion - Piston Machining
Turbo Mini Forums

Hello All,

I know that there have been a few conversions documented on here.

Can anyone help with dimensions for the machining of the pistons for the valve cut outs, specifically has any-one got dimensions to hand relative to the centre of the piston as I believe that the valves are not central on the bore ?

Engine I have is 1330cc with 21253 pistons, these are currently 0.3mm proud of the block, is this OK (I have taken this into account for the CR calculation).

Many Thanks

Mark

you should measure this yourself, as the placement of the head on the block varies, and also could be optimised fairly easily...

Yes but as you can buy off the shelf pistons (MED for example) there must be a "safe" set of dimensions. Just trying to get things done quicker.

erm, I think Uncle carl at force racing can do this for a reasonable price

yes I am sure carl could do this for you.

You could also do it yourself, I am aware some people have done it with a dremel or like me make your own cutting tool and do it yourself. Each head will sit differently on the block, so you are best to match the valves to your pistons. Don't forget you will need to incorporate the cuts into your volume.

Alternatively keep a look out as these pistons do come up forsale at times which is always an option

In respect of you pistons being proud of your block, I personally think you should machine these, it suggests you block has already been skimmed, you don;t want the pistons bouncing off you head.

Edited by philc on 9th Apr, 2014.