What is biggest bore you can go to

[Nomad54]

Got in touch with IMD pistons. Looking to go up to +60 as there are some marks in the bore ( corrosion ) from lying to long in damp shed. The bores are + 40 at the moment so looking to take them to + 60 in the hope of cleaning them up. The guy at IMD recons I would be better to get the barrels re sleeved as going to +60 is getting close to the bone. What are your thoughts.
Cheers Tom

[limeyrob]

Depends on your plans for the bike.  If you plan to keep it then go for a re-sleeve as it is the better fix.  More choice of pistons, a nice bore and the possibility to re-bore again in future.  Mine is on +60 and I'll hone and run with existing pistons as I'm not sure what my plans are yet.  I would also take the view that the piston manufacturer knows his stuff so his advice is worth something.

[Greybeard]

I once went to a committee meeting of the BSAOC. That was pretty boring. I won't go again.

[Worty]

I once went to a committee meeting of the BSAOC. That was pretty boring. I won't go again.

You got there before me GB, although Keir Starmer is a fine contender. 

I'm on +60 with a light hone and new Gandini rings (courtesy of Bergs rebuild).  It won't do a starship mileage, so I'll address the issue of a resleeve if:

1.  The rest of the motor holds up.
2.  I don't run out of cash.
3.  It doesn't outlast me.
4.  It starts to smoke like my dad's old Allegro.

[limeyrob]

So it all comes down to whether the corrosion will come out on a bore from 40 to 60.  Despite my earlier comments +60 is fine, but if the corrosion is deep then go for a sleeve.  Clean it up with some emery and try to get a measurement.  Surface corrosion will be very shallow but if there are pits that's another matter and you really have to dig a bit to get to the full depth.

[mark]

Have +80 Wiseco pistons in my 55 Road Rocket, no issues in 2000 miles so far

[sean]

I went with the IMD liners and pistons no problems so far but compression on them is 7-1 seems to run fine on e10 as no options for ethanol free here now. The circlips are fun to get in place very thick wire .

[Nomad54]

Spoke to Andrew at IMD pistons who was going to do the complete job of fitting new sleeves but has told me it is to a complex job for them to do. As I live in central Scotland it is hard to find a good engineering company to do this job. Can anyone advise me of someone who has done this job before successfully.

[limeyrob]

There's a lot of engineering expertise in Aberdeen because of the oil and gas and ship repair.

[sean]

Spoke to Andrew at IMD pistons who was going to do the complete job of fitting new sleeves but has told me it is to a complex job for them to do. As I live in central Scotland it is hard to find a good engineering company to do this job. Can anyone advise me of someone who has done this job before successfully.

cant help you there I am across the pond and the shop that did mine I would not recommend 4 months to do the job and I had to spens the best part of a day cleaning up the mess they made .....you could try Seager Engineering in UK may they can recommend if they are too busy.

[groily]

Spoke to Andrew at IMD pistons who was going to do the complete job of fitting new sleeves but has told me it is to a complex job for them to do. As I live in central Scotland it is hard to find a good engineering company to do this job. Can anyone advise me of someone who has done this job before successfully.

Unless postage is an absolute No No for what are heavy bits, I'd always recommend a call to T&L Engineering in Beds: https://vintage-engine.net/
They've done a few resleeves, rebores, crank grinds, valve seats, crankcase repairs etc for me over the years, and always made me happy.

[Macbeth]

Apparently not as big as my gudgeon damaged my bore ! 

[bikerboy]

Apparently not as big as my gudgeon damaged my bore !
----------------------------------------------------------------

Yes I was shocked when you said it was to deep to sleeve it. I have had them resleeved when 3/4 of the skirt had broken away with no problems.

Maybe I am missing something but thats one of the basic ideas of a resleeve. Reason one bore now too worn to rebore or reason two gouges in the bore that are too deep.

Maybe somebody on here can tell me why gouges would stop a resleeve because I cant think of a reason unless the gouges are about 2 inches deep 

[muskrat]

G'day Fellas.
The OD of cylinder liners is 73mm which is roughly 0.120" over std bore. http://tinyurl.com/59fp7he3
Cheers

[sean]

if you did bore to Max, finding pistons would be your next problem its the reason I went  with IMD liners and pistons now back to std bore