Cylinders, Pistons, and Rings oh My

[dan filipi]

I have 2 '83 1100 engines.
One is in my runner, the other is in a parts bike.

The runner has the infamous "knock" and a problem with 4th gear popping out under load.

The parts engine condition is yet unknown. I have run it even though one cylinder has a bent intake giving me 0 compression, the other 3 had 165 compression.
The starter clutch is frozen with visible rust through the starter hole.

My plan is to split both of these engines and build one good one together with other engine parts I have on the shelves.
I'm always on a tight budget but I want to do this right and naturally not spend any money if not needed.

In this post I need to learn myself about pistons, rings and cylinders.

Of the 16 pistons I have I should have 4 good ones.

My questions then are about prepping a cylinder, what parts needed, and the process involved.

Working with 4 good pistons:

I plan to condition the cylinders but not bore them since I'm using old stock size pistons.
1. If I hone, must I install new rings?
2. Will it break in properly if I use good used rings that measure within spec?
3. I have a honing tool and have read online how to hone but any information you can provide about the process is appreciated.
4. When honing, should the top ridge be removed?

 

[slabghost]

crosshatch is honing.
1. If I hone, must I install new rings?
I've never heard or read of anyone trying to re use old rings because it would be such a pain to tear it all down to replace them if they don't seat.
It's been many years since my last rebuild of any motor but if memory serves the hone must be constantly in motion fluidly moving in and out at the same rate to bust the glaze and create the crosshatch pattern.
4. When honing, should the top ridge be removed?
yes the ridge should be removed or you risk damage to pistons or rings at high rpm.

 

[dan filipi]

Saber cycle sells a complete ring set for $35.
I sent a message asking what brand they are.
Do I dare take a chance with them?

 

[slabghost]

I'd sooner chance no name new rings than try to reuse old rings. Be sure the piston grooves are clean and follow all the specs in installing the rings.

 

[dan filipi]

Saber's rings are NPR, Nippon Piston Ring Co., Ltd.

Are these ok?

I'll be checking around, not saying I'll be buying them but it gives me a basis for comparison.

WOW, Honda OEM is $54 per piston ring set!

 

[mcgovern61]

Saber's rings are NPR, Nippon Piston Ring Co., Ltd.

Are these ok?

I'll be checking around, not saying I'll be buying them but it gives me a basis for comparison.

WOW, Honda OEM is $54 per piston ring set!

:shock: :shock: :shock: :shock: :ahem:

 

[slabghost]

$35 compared to $208?!! That's a no brainer in my book!I'll take my chances with NPR at least they are still Japanese and may in fact be the OEM supplier.

 

[Flinx]

Saber's rings are NPR, Nippon Piston Ring Co., Ltd.

Are these ok?

I'll be checking around, not saying I'll be buying them but it gives me a basis for comparison.

WOW, Honda OEM is $54 per piston ring set!

truth be known I think that is the manufacter of honda rings in the first place
Nippon Piston Ring Co., Ltd

Beat me to it Chas, I couldn't find my reference to it but I do seem to recall that company when I was helping out a buddy with a very old CB750K.

 

[dan filipi]

I really like the SC price and from what I can find they are good rings so I'm going with them.

With this build I'll have many questions but I'm going to keep each separated into it's own post.

Thanks guys.

I'll have more questions for sure.

 

[dan filipi]

Well I've had a lot of practice honing on the bad block so now I'm looking at the next steps in cylinder preparation .

Piper15T is sending me a bore gauge and mic, I'll be able to measure the cylinder from top to bottom for taper, runout, and width.

While measuring the top end of the cylinder with a caliper I find according to the manual they are worn close to the books serviceable limit, same with the piston skirt.
When the proper tools arrive I'll know better but I think I'm looking at new pistons to do this right since the piston to skirt clearance is too large, at the cylinder top anyway.

I'm presuming this clearance being too large will cause piston slap?

I've found metricpartsoutlet.com
It lists all pistons from standard to 1.0 over as well as rings available, I'll be calling them to confirm this.

Ok so.....the cylinder is steel, the piston is aluminum.

If the cylinder is within serviceable limits, installing new standard pistons and rings I should be good?
Is my thought process correct, the aluminum (piston) wears well before the steel?

I would imagine the utmost "best' way to go about this is to bore 25 over and install oversize pistons but am I OK running with cylinders close to the "serviceable" limit since the steel is harder?

 

[slabghost]

If the cylinder is within serviceable limits, installing new standard pistons and rings I should be good?
Is my thought process correct, the aluminum (piston) wears well before the steel?

I would imagine the utmost "best' way to go about this is to bore 25 over and install oversize pistons but am I OK running with cylinders close to the "serviceable" limit since the steel is harder?
Since "serviceable limits" is at time of rebuild. I'd say yes standard pistons should be okay.
If you have pistons near serviceable your machinist friends may be able to knurl them to useable size. This might be especially good at the skirts to eliminate piston slap.

 

[dan filipi]

knurl, what's that do?

 

[slabghost]

Knurling will in effect enlarge the piston.

 

[scdmarx]

What you can measure at the top of the cylinder with caliper is going to be the ridge, no? I'm trying to imagine how you'd measure below the ridge with a caliper.
By the way, I have a ridge reamer that I haven't used in years. You're welcome to borrow it under the condition that you video and picture document your rebuild project for all of us here to see. arty:

The ridge is created from the rings wearing away the cylinder metal. That's the end of the top "compression" ring travel during the stroke event. Once you've disturbed these parts, there is a real possibility that the rings (especially new unworn rings) will hit that ridge at the top of the stroke. When this happens, rings can break, and also the ring lands where the rings ride in the piston will break under the pressure from being "hit". Now you end up with broken rings, broken piston, or both. And in most cases, a scored cylinder wall. I strongly recommend cutting the ridge. It just would be stupid not to.

I gotta go now. Sorry.

 

[dan filipi]

As far as the ridge goes I don't feel anything and the hone seems to be contacting the cylinder evenly all the way from the very top to bottom.
Is there still a need to ream it?

 

[scdmarx]

As far as the ridge goes I don't feel anything and the hone seems to be contacting the cylinder evenly all the way from the very top to bottom.
Is there still a need to ream it?

No. For some reason I thought you had a ridge. If you can't feel it, then there's nothing there to be concerned about. That's a good thing.

 

[dan filipi]

If you can't feel it, then there's nothing there to be concerned about. That's a good thing.

That's what I thought, just wasn't certain.

So just to double check myself, on the other cylinder I'm tearing up......I mean practicing on, there would show a line of untouched by the hone at where there would have been a ridge.
I've run the hone, not really very much and the ridge is gone.
Is this method OK for removing that ridge?

 

[Piper]

I didnt know they knurled pistons anymore. If you have them knurled, each one has to be "fit" to the cylinder when you get them back.

 

[slabghost]

I didnt know they knurled pistons anymore. If you have them knurled, each one has to be "fit" to the cylinder when you get them back.

I don't "know" they do either. Its been 30+ years since I rebuilt a motor. If memory serves it also reduced friction from the pistons and improved performance slightly. So my thinking is if they can be knurled to size it may be a cheaper and better option than new stock pistons. Not sure though. My experience is limited and long ago.

 

[Piper]

It's been a long time since I've built car engines as well slabghost, Dan will know more when he measures the bore and checks for taper etc. The ideal would be to bore .025 over and use new oversize pistons but it would kill the idea of rebuilding it on a budget. The lack of much of a ridge on top of the bore might indicate that the engine is not a really high mile engine. Are chrome rings standard on the 1100 engine? I would guess they must be.