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Discussion Starter · #1 ·
Anyone out there know the standard piston size? What is the actual diameter measurement for a standard piston and what is the cylinder bore supposed to be?

I'm in the process of honing out the cylinders to get rid of the rust that accumulated on a salvage yard bike.

I'll probably need to re-bore the cylinders as they are pitted from the rust pretty badly.

I'm wondering what oversize piston I need to go to.

I have a reproduction copy of the shop manual, but the table for the piston size and cylinder bore is blank.

Any help would be greatly appreciated! Thanks
 

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It's blank in my manual too - ??

I see listings of 50mm as stock bore (41 mm stroke) in most sources.....

If you need to bore, go to second over (0.5mm). Take the pistons to the machinist - he'll measure and bore to make sure you have perfect clearance each side.

I also know that the Chilton manual gives some weird info on it, not sure if I'd pay any attention to it.
 

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Discussion Starter · #3 ·
Right now i have then engine and cases split, and soda blasting the entire engine getting it ready for paint and re-assembly.

I will have to get the exact measurements of the pistons and bores, and see how they compare.

The pistons I pulled out have a .50 cast into the top of them. Are these the 2nd over size? So if they actually are the .5 oversized pistons will I need to go to .75 over size?

Due to the rust and pitting on the cylinder bores, I may need to go to the 1.00 over-size and bore, just so I can get rid of the pitting on the cylinder walls.

I have a bunch of pics here on the website.

http://sites.google.com/site/ingerslevc ... er-project
 

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r6100mph said:
The pistons I pulled out have a .50 cast into the top of them. Are these the 2nd over size? So if they actually are the .5 oversized pistons will I need to go to .75 over size?

Due to the rust and pitting on the cylinder bores, I may need to go to the 1.00 over-size and bore, just so I can get rid of the pitting on the cylinder walls.
I'm not used to seeing the numbers actually stamped in, but I guess they could be - usually I've seen the "0.5" just inked on, but whatever.
Allow your machinist to determine whether you can get away with 0.75 - he may feel it needs more.
That will cost a bit more, as he'll have to make more passes at it to get it spec.

I thought 160's were only made in 1968/1969 - Steve will know for sure, but he doesn't seem to be around today.......
 

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Discussion Starter · #5 ·
Not sure exactly when it was made. It's essentially a CL / CB hybrid. Some parts CL some parts CB, picked up from a salvage yard, so don't know a lot about the history.
 

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The .50 pistons ARE second oversize.... 160's were produced from late 1965 (66 CD model), and the CL's followed the next year ...The 66/67 CL's are really CL's (no CB that year in US) but the 67/68 CL's are actually "D" models modified at the dealer from the 67/68 CB versions (the CL's WITH electric start are modified CB's) ...

R6 probably has one of those "D" models.... Frame and engine have CB stampings....
This is my understanding from my hazy memory...... :lol: :lol: :lol:
 

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Discussion Starter · #7 ·
Yes I believe that's what we had discussed before, or was that on a different website.

Anyway, Like you said, I believe it's a "D" model because it has a CL front fender, electric start, but the CB front forks.

Either way the CL's and CB essentially have the same engine correct? maybe except for the electric start
 

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Cases are different, the "real" CL having NO provision (front loop in the casting) for the starter... Internally the same although I've HEARD some had different trans gear ratios, although I doubt it..... It likely became confused when we "cheetah's" slipped the 5-speed 175 engines in the 160 frame...... Bolt-in swap, and looks the same, but again different castings and some internals......:lol:
 
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