9n rebuild

[xj4343]

I'm trying to rebuild a 9n engine. I got the block tore down and cleaned. Went to remove the sleeves and I don't think I have any. I have a small ring around the top of the cylinder. did the sleeves have a lip that would go here. My cylinder walls measure 3.275 and my piston has .083 stamped on top. anybody seen this before. From what i can figure with my spec sheet. my only option is to bore the block and install .090 sleeves. anybody know the bore measurement for .090 sleeves.

 

[Dell (WA)]

xj4343.........yes, BOTH the original 0.040 sheetmetal sleeve and the BETTER 0.090 castiron sleeve have a "ring" or "lip" at the top of the sleeve. Boring a block is common engine machine shop practice. Me? I'd let the machineshop do the figgerin' 'stedda' you quoting some size. 'cuz iff'n they fugg'em-up, guess what??? Its their nickle. Also, 3-ring pistons are better than 4-ring pistons ........Dell

 

[TheOldHokie]

(quoted from post at 17:40:52 05/22/12) I'm trying to rebuild a 9n engine. I got the block tore down and cleaned. Went to remove the sleeves and I don't think I have any. I have a small ring around the top of the cylinder. did the sleeves have a lip that would go here. My cylinder walls measure 3.275 and my piston has .083 stamped on top. anybody seen this before. From what i can figure with my spec sheet. my only option is to bore the block and install .090 sleeves. anybody know the bore measurement for .090 sleeves.

What you have is not uncommon. The OEM piston size is 3.1875 and when fitted with .040 wall sleeves you get a block bore of:

3.1875 + (2 x .040) = 3.2675.

When the original pistons and sleeves sleeves wore out one option was to simply remove them and fit a .083 over (3.270) piston in the sleeveless block. Next time it needs rebuilding (your situation) the block has to be bored to fit the OEM .090 sleeves and pistons. That block bore is:

3.1875 + (2 x .090) = 3.3675.

It's a .001 interference fit and there may be some manufacturing tolerences to deal with so the best bet is give the shop the new repalcement sleeves. That way they can individually bore and finish to match the sleeves.

TOH

 

[Anonymous-0]

In the past, it was common to pull the original .040" wall sleeves and install .083" over pistons and rings that rode directly on the block surface...and of course wearing it out and eliminating any chance of going back to the thin-wall sleeves. About the only option is to have the block bored for the newer model 8N .090" wall sleeves.