Replacing Piston Rings

[Superdunc]

What are the bores made from on the RR8, before you waiving a hone at them.

I seem to recall they have some sort of ceramic coating rather than Nikasil coating or Iron liners. This and it's compatibility with the original rings is probably the route of the cause of your oil burning. It may not take to conventional honing.

[gsxr renegade]

What are the bores made from on the RR8, before you waiving a hone at them.

I seem to recall they have some sort of ceramic coating rather than Nikasil coating or Iron liners. This and it's compatibility with the original rings is probably the route of the cause of your oil burning. It may not take to conventional honing.

Not a clue tbh. I'm not gonna be doing it for a couple of months yet so I'll find out beforehand.

[gsxr renegade]

What are the bores made from on the RR8, before you waiving a hone at them.

I seem to recall they have some sort of ceramic coating rather than Nikasil coating or Iron liners. This and it's compatibility with the original rings is probably the route of the cause of your oil burning. It may not take to conventional honing.

Interesting. The bike has Nikasil coated cylinders and digging around a bit on the web, quite a few people are claiming that the manufacturers say these don't require honing when fitting new rings and honing can infact damage the cylinder coating as well as a few 'knowledgeable'* people. Apparently the best course of action is to either not touch them at all, or remove any glazing (if present) with a red Scotchbrite pad.

Others are saying they do need it, but it must be done with a diamond honing tool, not a conventional one.

I'll obviously confirm this with my Honda dealer first hand before i do anything, but does anyone have any thoughts on it?

*well, i assume they're knowledgeable as their names are stuf like 'xxxx@such and such dealer'

[Evilchicken0]

On the JE Pistons link it says "deglaze" - so don't hone the bores

[chancho196]

I always use fine wet & dry by hand with lots of WD40, unless we're talking old cast iron barrels or steel liners. The coating will be incredibly hard and you won't be taking it off with a quick rub - oo'er. Scotchbrite is also a good method, and probably safer/slower.

The vast majority told me not to touch the DLC on my fork stanchions because it was so microscopically thin. I smoothed a tiny chip out with wet & dry, and gave them the old 'crosshatch motion' with a green scotch pad and miraculously nothing bad happened. Except that the forks have never been so dry.

Obviously up to the individual at the end of the day, and that's where the experience comes in, but I certainly wouldn't go to all that trouble and not rough up/deglaze the bores in some way.

[gsxr renegade]

I always use fine wet & dry by hand with lots of WD40, unless we're talking old cast iron barrels or steel liners. The coating will be incredibly hard and you won't be taking it off with a quick rub - oo'er. Scotchbrite is also a good method, and probably safer/slower.

The vast majority told me not to touch the DLC on my fork stanchions because it was so microscopically thin. I smoothed a tiny chip out with wet & dry, and gave them the old 'crosshatch motion' with a green scotch pad and miraculously nothing bad happened. Except that the forks have never been so dry.

Obviously up to the individual at the end of the day, and that's where the experience comes in, but I certainly wouldn't go to all that trouble and not rough up/deglaze the bores in some way.

Indeed. If there is a glaze, i'll probably take it off with some scotchbrite while i'm there It'd be silly not to while i've got the engine in bits. I'll be interested to see how much of a glaze has built up as it's only done 8000 miles. Probably 9 by the time i come to actually doing it.

I worked it out today, i'm putting 200ml of oil in for roughly every tank of fuel that i burn through.

edit: which for me, is about 4-500ml of oil a week. Sometimes up to 800ml per week. You can see why i want to stop it using oil!

[chancho196]

Cool, plenty of pics would be good. Is it in bits yet?

[gsxr renegade]

Cool, plenty of pics would be good. Is it in bits yet?

nah, nowhere near yet. Still got a few bits to buy and a holiday to Cyprus to take care of first.

I'll probably tackle it end of August/early September. Lots of pics will be taken.

[chrisexup]

Good point about the oil you use. I remember a mechanic saying Silkolene was a good oil to use on my exup. as it didn't get past the rings/valve seals? as easy as most oils.....? Got to be worth a try....

Something else i seem to remember is that the rings have to be a certain way up ?

https://www.hastingsmfg.com/ServiceTips/compression_ring_installation.htm

[Mark/Foggy]

Cheers for the advice guys. I've had a bit of a read through the service manual and it doesn't seem too difficult, just incredibly methodical. The biggest pain seems to be all of the ancillary stuff i need to strip off the engine to get the crankcases apart. Going to need a lot of containers!!

I'll have to install the pistons individually through the top of the cylinder. I can't remove or install them from the bottom up as the rings will get caught in a gap between the cylinder lining and the upper crankcase and cause the pistons to become stuck.

Well if they've got to come down from the top then you're into Big End Shells and probably new Rod End Bolts. If that's the case be very careful marking the Big end caps for each rod and orientation. Not overly sure about the Big H, but a lot of rods are manufactured complete and the caps are 'snapped' off. These two components end up with a granular surface and the match between the 2 has massive bearing surface advantages allowing for greater finesse in the design. So don't think about mixing the caps up (would be bad practice anyway).

Not so sure that you can't drop the barrel onto the pistons though. If Haynes are recommending from above and show a ring compressor in the photos, it'll be that the compressor will get stuck because there's a skirt on the bottom of the barrels that would stop you getting the compressor out and it will get caught! You should be able to see from the photos if the skirt has scallops cut away between each bore: these are generally there to minimise windage losses and minimise weight as the piston forces are going fore and aft. Now it is possible to jam a piston as a ring gap gets snagged by the cutaways, conversely those cutaways can be your friend in ensuring that you can wriggle the rings a bit with a fine,soft, blunt object.

While you're looking at the photos, see if you can spot a lead in chamfer at the bottom of the Liners/Barrels. Some manufacturers used to leave this out making piston and ring insertion a nightmare. On an Iron liner cutting a chamfer to assist assembly wasn't an issue, but if you had to do this to a ceramic plated bore, I'd take serious advice, chips in the plating in this area could lead to rapid wear on the pistons.

[gsxr renegade]

Well if they've got to come down from the top then you're into Big End Shells and probably new Rod End Bolts. If that's the case be very careful marking the Big end caps for each rod and orientation. Not overly sure about the Big H, but a lot of rods are manufactured complete and the caps are 'snapped' off. These two components end up with a granular surface and the match between the 2 has massive bearing surface advantages allowing for greater finesse in the design. So don't think about mixing the caps up (would be bad practice anyway).

Not so sure that you can't drop the barrel onto the pistons though. If Haynes are recommending from above and show a ring compressor in the photos, it'll be that the compressor will get stuck because there's a skirt on the bottom of the barrels that would stop you getting the compressor out and it will get caught! You should be able to see from the photos if the skirt has scallops cut away between each bore: these are generally there to minimise windage losses and minimise weight as the piston forces are going fore and aft. Now it is possible to jam a piston as a ring gap gets snagged by the cutaways, conversely those cutaways can be your friend in ensuring that you can wriggle the rings a bit with a fine,soft, blunt object.

While you're looking at the photos, see if you can spot a lead in chamfer at the bottom of the Liners/Barrels. Some manufacturers used to leave this out making piston and ring insertion a nightmare. On an Iron liner cutting a chamfer to assist assembly wasn't an issue, but if you had to do this to a ceramic plated bore, I'd take serious advice, chips in the plating in this area could lead to rapid wear on the pistons.

It's from the Honda service manual, not the Haynes. I've not read the Haynes yet to see what they say about it, although i'd be more inclined to trust the Honda manual over the Haynes one.

Just before the section on removing pistons, there's a little box saying 'NOTICE' The exact wording is;

"Do not try to remove the piston/connecting rod assembly from the bottom of the cylinder; the assembly will get stuck in the gap between the cylinder liner and upper crankcase."

Then it mentions it again later on and says the assembly will get stuck when the oil ring expands into the gap between the cylinder lining and upper crankcase.

The pictures aren't great as it's a scanned copy, but there doesn't look to be a chamfer at the top of the cylinder.

edited to add: crankpin bearing cap bolts are one of the items i'll need. these can't be used again once loosened apparently.

[Mark/Foggy]

There certainly won't be a chamfer at the top. You'll need compressors, actually only the one. I'm getting lost in this, what years the bike, might have a hot-line to some-one whose built dozens of them. Probably can't get his number 'til weekend after next, willing to ask though.

[Superdunc]

It's an RR8 I believe, which has a separate cylinder block. Don't see the need to be removing rods or splitting crank cases.

[gsxr renegade]

Indeed it is a 2008 RR8.

I'm just going by what the manual says as i need to remove the pistons to replace the rings. From what i can see, i'm not sure how you could remove the pistons without splitting the cases to unbolt the conrods from the crank.

Mark - Really appreciate that - i don't want to put you to any bother though as i won't be making a serious decision about attempting it until the end of August at the earliest.

Just to stress again, i'm not going to do this unless i'm 100% confident about doing it, i'm more just chucking ideas etc. around at the mo and looking for tips etc. When the time comes, i'll be looking into the cost of getting a pro to do it as well and being realistic with myself as to whether this is too big a job.

[Mark/Foggy]

No stress bro, just a possible available resource. Currently bored 'cause I've not taken anything to pieces for a couple of weeks.

Like Dunc, can't see why the rods have got to come apart.

Head off, barrel off, replace rings in situ. .............And as the Haynes legend suggests ' Replacement is the Reverse of the Dis-assembly Procedure'

^ This of course is usually a lie

But, not beyond the wit of man

Sod the manual

You'll walk it.

[Hendo]

Just thinking out loud but have you thought of trying semi synth in it instead of fully synth oil?

Will do the bike zero harm, will be cheaper to buy and may just use less.

I'm sure this was the case with the old Yams, they drank much less with semi synth.

[Elohesra]

Go to your local tip and get an old Briggs and Stratton mower engine to practice on.

You'll find they're virtually identical to the Blade.....Arf! Arf!

[Wildbill]

Them old Yams you allude to run perfectly well on 15/40 diesel mineral engine oil which costs the pricely sum of exactly SFA per 25litre drum in my case. In fact if I could get them to run on cherry I would.