nikasil

[roofeditor]

cylinders?

I notice there are a few guys on the v-twin site that think that the 107 big bore kit with the nickasil cylinders is the thing.

Question #1. do you think that boring to 107 is too much and thins the walls?

Question #2. do you think the nickasil coating will hold up for 100,000 miles or so?

Question #3. do you think an aluminum only cylinder will hold up on a air cooled only motor.

I know the German cars like BMW, And AMG Benz are using this very effectively but a air cooled twin might be different.

Thanks in advance for your opinions.

[Mike]

The jury is still out. Us old timers tend to like "sleeved" cylinders. We believe they hold their shape better. The guys at Revolution Performance use Nickasil exclusively and they appear to working fine. We've built several motors using them with no problems with the exception of some race stuff using gas ported rings, they tend to microweld and push the bore. Maybe a ring material change could solve this issue (Merch experianced the same thing) ans I would probably not use gas porting with Nicom. The all aluminum construction allows thinner walls equalling slightly larger bore diameters for the same spigot outside diameter and so, slightly larger motor size. I.E. 97ci vs 95 with lined cylinders.

1. The case thickness in TC's is not a problem.
2. Should last 100k easy, so long as detonation is controlled. Detonation can cause the bore coating to push into the aluminum, failing the plating.
3. Destortion is a big concern, especially since we are pushing wall thickness to gain bore diameter.

I can say that with the above exceptions we have not experianced failures and those we've built are doing fine, as far as we know.
Mike

[roofeditor]

Thank you, I suspect the same things you might. I do know BMW had problems with poor quality gas and nikasil coating. From what I think you said going to 107 by boring a 96 engine is not going too far? Boring a steel lined aluminum cylinder not a parent bore aluminum cylinder.

[Mike]

I was referring to the case boring to accept the larger cylinders. Stock cylinders cannot be borred to 107ci (4.125 bore) but can be bored to 95 (3.825 inches). 97ci (advertized 98) can be achieved with Nickasil cylinders without boring cases. Cases can be bored to accept up to 4 1/8 bore sleeved cylinders or 4 1/4 Nickasil.
Mike