Minimum cylinder wall thickness?

[4v6]

Does anyone have a guide on whats an acceptable minimum cylinder wall thickness for a turbo application?

The engine in question is a 5 cylinder diesel block with a bore diameter of 79.5mm.
This particular block comes from VW's T4 transporter van and has a 95.5mm crank throw which I want to run as a petrol application, enlarging the bore to a more useful 82.50mm, which should give a displacement in the region of just over 2.5litres.

Ive had a look in the usual places with some suggestions ranging anywhere from 60 thou to over 200 thou, so quite a varied range.
Obviously Ill need to have the block sonically checked to ensure its already usable.

Any help appreciated.

[Pumaracing]

There is no single figure to work with. It obviously depends on the stresses involved. However boring any modern block by 3mm is asking for trouble, especially if it's turbocharged. They are usually computer designed to minimise weight for the forces encountered and there's rarely much spare meat. You could do it on Minis and MGBs back in the day when everything was cast very thick. 1.5mm to 2mm is a safer limit for a modern block unless you have definitive information otherwise on your particular one.

[stevieturbo]

And lets face it...if it's turbocharged, do you really need that extra capacity ?

[AndyS2]

What's the engine code of the block you've got?

I've done this conversion and as far as I know there are only 2 blocks you can safely use, AEL and AAT. I've seen pictures of one done with an AAB block from a 2.4D transporter and it holed the liner!

[AndyS2]

http://www.s2forum.com/forum/showthread.php?t=2720...

Don't take a chance, use the AEL/AAT block, they've been proven to do 1000+bhp.

[4v6]

Thanks for all the replies fellas, looks like the AAB block goes in the skip then and ill start with the AEL or AAT.

[AndyS2]

What's it going in, and what spec you building it to?