Best way to fit 1000cc Nicasil to early R90/6 cases?

[Major Softie]

I've been contemplating this as well. I have a 1975 R90 that seems to have the last small spigot block ever made (manufactured in Sept 1975). I don't want to bore out the block at this point.
First question, can an iron cylinder be given the "Nicasil" coating?

I do not know, but why? The point of the coating is to make an aluminum bore capable of wearing like iron, or even better. Since the process is designed for coating aluminum, it may not work, or even be tested, on iron.

2nd, I noticed that the Siebenrock 1070cc kit doesn't have spigots on the barrels. They are flush on the bottom. At least the picture in my catalog doesn't show them. It uses pistons with very short skirts. How do they keep the barrels in alignment with this set up?
I guess what I'm getting at is...would it be possible to use 1000cc Nicasils with the spigot cut off and modified, short skirt, pistons on a pre-1976 block?

I suppose, with carefully machined holes for dowels, it could be done, but probably much more difficult to do perfectly than enlarging an already existing round bore.

[melville]

I've been contemplating this as well. I have a 1975 R90 that seems to have the last small spigot block ever made (manufactured in Sept 1975). I don't want to bore out the block at this point.
First question, can an iron cylinder be given the "Nicasil" coating?

I do not know, but why? The point of the coating is to make an aluminum bore capable of wearing like iron, or even better. Since the process is designed for coating aluminum, it may not work, or even be tested, on iron.

LN Engineering in Chicago, who make custom Nicasil alu cylinders, do this for some special VW and Porsche 356 applications.

[Max Headroom]

I've been contemplating this as well. I have a 1975 R90 that seems to have the last small spigot block ever made (manufactured in Sept 1975). I don't want to bore out the block at this point.
First question, can an iron cylinder be given the "Nicasil" coating?
2nd, I noticed that the Siebenrock 1070cc kit doesn't have spigots on the barrels. They are flush on the bottom. At least the picture in my catalog doesn't show them. It uses pistons with very short skirts. How do they keep the barrels in alignment with this set up?
I guess what I'm getting at is...would it be possible to use 1000cc Nicasils with the spigot cut off and modified, short skirt, pistons on a pre-1976 block?

The Siebenrock kit also includes longer conrods with their short piston skirt design. Pistons are less likely to rock around in the bores with a short compression height. It's all part of an integrated package.

[mattcfish]

I've been contemplating this as well. I have a 1975 R90 that seems to have the last small spigot block ever made (manufactured in Sept 1975). I don't want to bore out the block at this point.
First question, can an iron cylinder be given the "Nicasil" coating?

http://www.finishing.com/1600-1799/1671.shtml
This discussion confirms that you can send your iron lined barrels out and have them plated.
You won't get the advantages of the light weight aluminum cylinders, but you will get the increased ware resistance.

[mattcfish]

San Jose BMW (CC Products) has these aluminum liners to repair late R100's. I wish someone would make alloy liners for early R90 bikes so we could get all the bennefits of Nicasil. Remove the iron liner and press in the aluminum one.

[Major Softie]

http://www.finishing.com/1600-1799/1671.shtml
This discussion confirms that you can send your iron lined barrels out and have them plated.
You won't get the advantages of the light weight aluminum cylinders, but you will get the increased ware resistance.

That's cool, Matt. I didn't know about that but it's handy info.

I assume they have to run the bigger clearances though since you still have aluminum pistons expanding in Iron sleeves.

[Garnet]

I thought I'd drag this back up. I thought it was Siebenrock that made a small spigot 1000cc kit.

Turns out it was MI:

http://www.motoren-israel.com/products/ ... -1975.html

[pkboxer]

Think this has been posted before, don't know if it's of interest here.
They are local here, near Cincinnati

http://www.bore-tech.com/carbidebore.htm

[Armaguidon13]

aloy sleve in steel cylinder is not interesting.
The interest of aloy cylinder and chrome is heat "going out strait" no chrome to aloy, to steel. so better cooling.
Chrome on aloy allow to reduce gap between cylinder and piston as piston (aloy) and cylinder (aloy also), expend particly the same amont with heat.

[mattcfish]

aloy sleve in steel cylinder is not interesting.
The interest of aloy cylinder and chrome is heat "going out strait" no chrome to aloy, to steel. so better cooling.
Chrome on aloy allow to reduce gap between cylinder and piston as piston (aloy) and cylinder (aloy also), expend particly the same amont with heat.

What I meant was, to punch out the iron liner and replace it with an alloy sleave for 900 and lower cc models.

On another subject, I talked to Siebenrock about there 1070cc kits without a foot to fit inside the block. Apparently they used to put dowels on the the lower studs for alignment but found it unnecessary. It makes me wonder if you couldn't just cut/mill the foot off of regular 1000cc Nikasil jugs and bolt them onto an early block with 97mm spigots. How far would the piston skirt extend into the block? Would that be an issue? It seems like it would actually help with lower skirt lubrication.
Much simpler than stripping down the block and boring out the spigots to 99mm.