Topic: sleeve question-answer.

[Don R]

 Can a set of large bore sleeves be moved to another freshly machined cylinder and then be used as is with their matching pistons, or do they need to be replaced then bored and honed to be round? Thus making it more sensible to get new sleeves and probably modern pistons. 
  Two of the sleeves in question are, for whatever reason, low in the block and do not seal to the head gasket. I have no idea if they moved or if this was the result of faulty previous machine work. The cylinder looks like the one in CycleX's picture captioned "do your big bore cylinders look like this" 

  Their pic shows a grungy sleeveless cylinder with red silicone and locktite all over it.

[grcamna2]

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[PeWe]

My shop removed freshly installed sleeves with little use  to improve the seal between sleeves and cylinder by milling it wider in the bottom for o-rings and sealer on top.
Max 1000km used, 74.5mm OD, 70 inner.

He marked with punch marks exactly how each sleeve sat so he could get them back exactly how they sat, not rotated.
This to ensure the wear. Maybe a very light hone too.

I guees you need to hone after assembly since the sleeves will sit different. Probably not exactly the same bore clearance/crimp either.

[Don R]

 Thanks, that's good to know. I guess I should talk to Ken at CycleX then. I'm hoping to go there.
This thing had o rings in the bottom of the sleeves that came out and were eaten by the rotating assembly, there was also an o ring that had stuck to the bottom of the copper head gasket. I think the previous owner gave up on it and just slammed it back together.
 At one race he was asked if he would submit to a tear down because he was running close to the class record and they wanted him to be aware that it could happen if he got there. I'm not sure what class or if it was actually legal.

[PeWe]

"Two of the sleeves in question are, for whatever reason, low in the block and do not seal to the head gasket."

This has been up before on this forum when sleeves are not correctly seated when mounting them.
They can pop-up when cylinder cools down. Important to press them down.
Surface decked flat with sleeves wrong. When running the engine warm sleeves will sink.

Here a photo of marked sleeve that was removed and back again. Cyl 4, all the other marked too.


The 970cc cylinder I have used 2022, a little bit over 10.000 km after that fix.

Changed head 2 times, last swap I fixed a leaking RCS base basket. Reused same gasket, just a very thin layer of high temp RTV on both sides, let it cure a few hours before assembly.
Last time I got cam better timed than before getting 3whp more than earlier 104.5whp. Pod clean might have helped to.

Redoing things can sometimes improve, not only repair.
I reused an MLS head gasket too so no extra costs for gaskets.
I tightened that one less when  used before for a short period.

[Don R]

 The cyclex site says these big sleeves may rotate in the cylinder if they weren't honed to fit tightly enough. I'd guess that is the case.
  I have a decent early cylinder to get machined, if it's decided these sleeves shouldn't be used, new will probably be better.
  The plan is for this beast to start and run, no long trips or racing since it's a welded stroker with aluminum rods.
  Mostly a tribute bike to Tom, he was a cb750 guru for a long time.

[PeWe]

My 970cc sleeves were ordered from CycleX when they had good price on them, $129US. A year and a half ago.
I should have bought an extra set just for sure, as their stepped sleves I bored to 890cc. OD74.2mm, ID 64mm also for that good price.

[MRieck]

The cyclex site says these big sleeves may rotate in the cylinder if they weren't honed to fit tightly enough. I'd guess that is the case.
  I have a decent early cylinder to get machined, if it's decided these sleeves shouldn't be used, new will probably be better.
  The plan is for this beast to start and run, no long trips or racing since it's a welded stroker with aluminum rods.
  Mostly a tribute bike to Tom, he was a cb750 guru for a long time.

Be careful with your valve to piston clearance with those aluminum rods. At least .060 intake and .080 exhaust. Even that's no guarantee with 50 year old aluminum rods.

[Don R]

The cyclex site says these big sleeves may rotate in the cylinder if they weren't honed to fit tightly enough. I'd guess that is the case.
  I have a decent early cylinder to get machined, if it's decided these sleeves shouldn't be used, new will probably be better.
  The plan is for this beast to start and run, no long trips or racing since it's a welded stroker with aluminum rods.
  Mostly a tribute bike to Tom, he was a cb750 guru for a long time.

Be careful with your valve to piston clearance with those aluminum rods. At least .060 intake and .080 exhaust. Even that's no guarantee with 50 year old aluminum rods.

  Thanks for the heads up. The wise move would be to trade the stroker assembly in on a stock stroke 970 or so.  I think the rods were fresh but can't prove it. (Means nothing, I know) Two used sets left the auction where the bike was later bought. I wasn't buying anything else until I got the sandcast that was also there.
  I went back the next week for the drag bike. It wasn't part of the sale, but they realized I had CB750 fever, knew the late owner and still had money left over. $1800, but it had the ARD and rolled rim off of the sandcast.
 It appears Carillos are the remaining option, a set of new in box APE steel rods got away on Facebook recently.

[MRieck]

The last aluminum rods I installed....on George's engine base on his insistence...I ran at
080 in, .100 ex.....he said he was going to rev the piss out of it.

[Don R]

 Thanks, now I promise to shut up about this old engine until I actually do something with it.

[Don R]

 Ken at CycleX said he can re-set the sleeves with hard block and mill the cylinder flat. The piston domes are .125" out of the hole now so I should be able to add some deck height to correct the cut and maintain the current deck height.