Alusil coated blocks and boring

[bmgm3]

I read that Alpina had BMW cast them a 4.6L version of their 4.0L V8, because the alusil 4.0L block coulnd't be bored out because of the alusil coating. So does this mean that you can't enlarge any engines with this coating ? Could it not be re-coated ? Sorry if that'sa bone question, but as you may have guessed, I know little about it.

[Boosted LS1]

bmgm3 said:

I read that Alpina had BMW cast them a 4.6L version of their 4.0L V8, because the alusil 4.0L block coulnd't be bored out because of the alusil coating. So does this mean that you can't enlarge any engines with this coating ? Could it not be re-coated ? Sorry if that'sa bone question, but as you may have guessed, I know little about it.

It's not a coating. The silicon particles are mixed in with the aluminium before it's cast. You could bore and then insert iron liners. If the stock bore's not badly damaged I can reclaim it ready for re-ringing. I can also overbore and then finish it for re-ringing but you'd then have to get new pistons etc and that may make it prohibitive.

Boosted.

[martind]

Boosted LS1 said:

If the stock bore's not badly damaged I can reclaim it ready for re-ringing. I can also overbore and then finish it for re-ringing but you'd then have to get new pistons etc and that may make it prohibitive.

Boosted.

Boosted
Do you final finish with felt & paste ? Have you worked on a Can-Am Big block Chevy liner less block (Reynolds 390 = alusil ) ?

Martin

[Boosted LS1]

martind said:

Boosted LS1 said:

If the stock bore's not badly damaged I can reclaim it ready for re-ringing. I can also overbore and then finish it for re-ringing but you'd then have to get new pistons etc and that may make it prohibitive.

Boosted.

Boosted
Do you final finish with felt & paste ? Have you worked on a Can-Am Big block Chevy liner less block (Reynolds 390 = alusil ) ?

Martin

I've sent you a pm Martin, I do get the etching done properly and the finish is as smooth as glass

Boosted.

[knightly]

BMGM3 - I would strongly reccomend you read this thread before you start playing with alusil blocks. In short for an alusil blocked performance engine, over and above what BMW designed it for, when boring out the cylinders, either have them nikasil plated or have a set of dry liners installed......the thread below contains a lot of stuff thet you NEED t read!

www.pistonheads.com/gassing/topic.asp?t=306655&f=66&h=0&hw=BMW

.

[bmgm3]

Thanks all, but I'm not out to mod the motor. It was more just wondering after I saw that Alpina had BMW cast them a a new block for the 4.6L engine,and then thinking about if you could do even a mild rebore on this type of block. I do know someone who does dream of taking the 4.0L engine out to 5.0L though....

Cheers