Lip of sleeve at bottom of cylinder

[MasterChiefIDI]

Today I was assembling my motor when I noticed I have a somewhat sharp edge on 3 of my 8 sleeved cylinders. pressing a feeler next to this edge/lip I estimate it's about .010" maybe less. My machinist previously stated he added a 5/16 shoulder at the bottom of each cylinder for the sleeve to stop against and that the skirt should not extend below it.. well, it does..

Is this something others have seen on a sleeve job? Do y'all think I can just slightly slope the raised edge with sand paper and run it? thankfully, this edge is well below the rings. My main concern is skirt wear/piston slap.

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[IDIBRONCO]

Maybe ask your machinist again. Show him the pictures.
I don't know that this would contribute to piston slap since it's at the bottom of the travel. The wrist pin is higher than that ridge and I think that most of the side pressure should be at wrist pin height since that's where the pressure from the crankshaft is applied. That ridge may add to skirt wear like you said. I could also be wrong on my thinking above. Just a fair warning since I'm no machinist.

 

[jwalterus]

From my experience, that ain't right.....

A sleeve should completely fill the bore, I've never seen anyone do anything like that.

My machinist previously stated ..... that the skirt should not extend below it.. well, it does..

That alone is enough information that IMO he should be redoing it, show him that the piston skirt extends below the cylinder.

 

[ihc1470]

Often on repair sleeves the block is not bored all the way to the bottom before the sleeve is installed. The shoulder makes a positive stop so the sleeve can not drop. However usually you can not detect a difference like you are seeing. By chance was the block bore .020 oversize and is now back to standard? That would account for the difference. I do agree that you need to check with the shop that did this work.

 

[MasterChiefIDI]

Thank you for the feedback. This is terrible. I somehow missed it on pickup. This is the same machinist that messed up my first block and this is his replacement so I find it difficult he will be willing to make it right at this point. I will go see him today.. worst he can say is no. I had to purchase 2 other blocks before I found a good one for replacement so I really can't afford to do another block so not sure what I will do. I suppose a .020" OS bore could correct this..

 

[jaluhn83]

Normal. Will have no significant impact on engine operation. No action required.

A sleeve should completely fill the bore, I've never seen anyone do anything like that.

It's one of 2 standard ways to ensure the sleeve doesn't slide down over time. Other is a counterbore and flange at top but that isn't always possible. Frankly, it would be more worrisome if there wasn't a step like this. Screenshot is different engine, but illustrates point that it's standard work practice.

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[jaluhn83]

Often on repair sleeves the block is not bored all the way to the bottom before the sleeve is installed. The shoulder makes a positive stop so the sleeve can not drop.

However usually you can not detect a difference like you are seeing.

Bull. Think about it - the ID of the step is the old cylinder bore. The ONLY way the step will be the same as the sleeve bore is if the bore before sleeving was still stock with no wear. If it's been bored or worn it will inadvertently be larger than the new sleeve bore.

 

[MasterChiefIDI]

Normal. Will have no significant impact on engine operation. No action required.

Thank you for your input. I have essentially arrived at the same conclusion after looking closer. I see in that diagram there's a step in too. only diff is mine is like .31" and that is calling for like a .20" shoulder.

I've decided that given the rings and wrist pin are well above this area, I will use sand paper to take the edge off the step to reduce skirt wear. Given that the piston to cylinder wall clearance tolerance is as much as .0085" and this motor ran fine with .020" wear before sleeves, I feel like this step will not be too big of a deal. If it wears out my pistons, It'll just get a .020 bore then.

Appreciate everyone's input.

 

[Nero]

If it helps, you can mess up the hones down there as much as you like, so long as the are the piston rings travel is untouched.

 

[jwalterus]

It's one of 2 standard ways to ensure the sleeve doesn't slide down over time. Other is a counterbore and flange at top but that isn't always possible.

Learn something new every day.
Everything I've ever dealt with was primarily a drop in with a counterbore or line welded/line bored (those were decidedly non-standard as they were steel blocks, but so were the applications), have also dealt with a handful of straight sleeves that were interference fit with a bit of belzona as an additional retainer
Heck, even the little engines I've done have had a (albeit very small) counterbore and then have been decked to remove protrusion

 

[scsmith42]

Guys, I used to own a machine shop and have personally installed a lot of sleeves. Yes, this method depicted by the OP is not uncommon. The information provided above by Juluhn83 is what I recall from my younger years.

Typically, the only sleeves that have a flange at the top are wet liners that are designed to be replaced. Repair sleeves are just about always installed by leaving a slight amount of the original cylinder bore in place at the bottom so as to secure the sleeve in place.