[Brian_VACsales]

Originally Posted by BMRLVR

Their seems to be some confusion on what Alusil and Nikasil actually are.

There is no confusion - we know the difference between the 2 (lol). We have been dealing with Alusil and Nikasil for a long time

I can understand people's thoughts on sleeves as being a better alternative to going with a proper Alusil honing process, which many shops can not do to any degree of confidence. People and machine shops are familiar with sleeves and feel more comfortable working with them. Most (but not all) veteran machinists are not used to working with these newer alloy's since they have only recently caught on to the degree that people are bringing them to machine shops for modification/repair.

BMW enthusiasts started chatting about Nikasil/Alusil in the M60 days. Nothing recent about the M60 For reference, we have been building BMW engines in house since the 1980s.

Couple all of this with the fact that people generally think of iron as strong and aluminium as weak and the consensus is to sleeve the block as soon as any engine work is done.

In our experience, people who actually pay the money and buy engines do not have such a simple process. Most of our clients are racers who push the cars really hard and based on their actual hands on experience they choose the best solution for their needs.

One major drawback I see with sleeves in the S65 is heat transfer is greatly reduced when going from an aluminium bore to a cast iron liner (Alusil conducts heat at a rate 400% higher than that of cast iron). Since the S65 is very sensitive to knock, and knock is usually a result of higher cylinder temperatures, any means a person can take to get rid of heat will benefit the engine by means of additional timing and reduced detonation risk.

How many nikasil/alusil engines have you built/sleeved? How many sleeves have you supplied to people with these engines? We have done a bunch .

Sleeves may be good, but I have yet to see the S65 block itself fail without a rod first failing and going through the side of it. Personally I don't think anyone has gotten to the HP celling of the block casting yet and I would like to see it pushed harder before people just start doing sleeves out of fear

In our experience, people don't do sleeves out of fear. They make the choice based on actual experience.

some people like myself would like the option of keeping the Alusil block intact. I am very interested in building a stroker for my car much along the lines of what you guys have done with this one (Stroker crank, larger bore, cams, valve springs & retainers and possibly some head work) but I won't want the block sleeved. If you guys have the ability to properly bore and hone the Alusil block to factory tolerances and get me the MAHLE Alusil pistons in the proper dimensions we may be able to do business in the near future.

Call when you are ready, we can work up a quote for whatever you wish If you did not know, we are the largest global stocking dealer of BMW specific engine components.