Valve clearances

[yorkie_chris]

Did a few bits on melodys curvy on sunday, checked clearances and all were within spec except for the front right exhaust valve, this showed less that 0.2mm but more than 0.15mm.
So, I would say this is worth changing the shim so as not to risk the valve, anyone think otherwise?
How much will a shim be?

Chris

[Sid Squid]

Do it.

About £5-£7 depending on who sells it to you.

Read me. (http://forums.sv650.org/showpost.php?p=852749&postcount=6)

[yorkie_chris]

Right oh, dizzyblonde has a proper tensioner holding tool which makes life so much easier so shouldn't be too much trouble.
Any common pitfalls?

[Blue_SV650S]

Right oh, dizzyblonde has a proper tensioner holding tool which makes life so much easier so shouldn't be too much trouble.
Any common pitfalls?

How far 'in spec' were the others? I'd be inclined to replace them all whilst you are in there ... take them out to near max spec (largest gap) that way the job won't need doing again for ... well lets face it, the bike is already what 8 years old?!?! so probably ever (in Melody's ownership) 8)

[rictus01]

How far 'in spec' were the others? I'd be inclined to replace them all whilst you are in there ... take them out to near max spec (largest gap) that way the job won't need doing again ... well lets face it, the bike is already what 8 years old?!?! so probably ever (in Melody's ownership) 8)

whilst exhaust valve gaps do tend to close, inlets valves tend to open with wear, so setting them to the widest isn't wise.

Cheers Mark.

[Blue_SV650S]

whilst exhaust valve gaps do tend to close, inlets valves tend to open with wear, so setting them to the widest isn't wise.

Cheers Mark.

are you sure?? How does that work?!!? :smt104

[yorkie_chris]

Inlet valves run cold (if CVH escorts are anything to go by) so the valvetrain wears more than the seats do, opening the clearances.

I only did a loose check i.e a 0.2 gauge fit, a 0.3 didn't (exhaust valves) so not a clue what the rest are at with regards to how far each way they are

[Blue_SV650S]

Inlet valves run cold (if CVH escorts are anything to go by) so the valvetrain wears more than the seats do, opening the clearances.

I only did a loose check i.e a 0.2 gauge fit, a 0.3 didn't (exhaust valves) so not a clue what the rest are at with regards to how far each way they are

Still not convinced ... surely what causes the wear is the valves smacking into the head ... and the inlets have higher lift ... sure the heat of the ex might accelerate wear, but the inlets still get a hammering ...

I have done quite a few bike valve clearances over the years ... and I have NEVER had a gap go LARGER than spec (inlet or exhaust) ... not since days of tappets anyway ... well with the exception of when I have a bent valve ... that gap was pretty big!! :D

I suggest someone do a bit of googlefu to confirm or deny the allegation that gaps get larger (on bucket and shim OHC) ... I am not convinced that is the case - if for no other reason than through observation ...

[yorkie_chris]

I'm not too fussed either way, if I bother with more than 1 shim then I'll set them to the middle of their adjustment as they can go both ways.
Have seen them go tight and loose so will hedge my bets and put them halfway, if a little loose as thats the safer bet.

[rictus01]

...

yes it's right, whether you're convinced or not :smt102, understanding the thermal dynamic wear pattern on the different valve trains explains it quite logically, look it up, and I have seen valve gaps greater than spec.

but then you do post for effect, so it doesn't surprise me.

Cheers Mark.

[yorkie_chris]

thermal dynamic wear pattern

F#king hell

Thats a big term

[rictus01]

F#king hell

Thats a big term

true, but once again, not wrong.

Cheers Mark.

[yorkie_chris]

Indeed, and it appears to have shut blue up...

[Blue_SV650S]

Indeed, and it appears to have shut blue up...

What’s wrong with you people?!?!? :smt018

Anyway, having logged back on and seeing we have got no further, just done some quick googlefu myself (I don't care enough to do exhaustive search - especially if people are starting to be knobbers about it!! :smt011) and I came up with this (random first page links to mention reasons WHY) … you will note there is no mention of valve clearances opening during NORMAL operation … http://faq.f650.com/FAQS/ValveMiscFAQ.htm
search for/click {What causes changes in Valve Clearances?} And another http://www.motorcyclistcafe.com/forums/showthread.php?t=191 (second post)

So once again, I put it to you to find some supporting evidence to the claim that inlet valve clearances open and I'll start to listen ... its going to take more than your mutual back slapping to convince me to the contrary of my own observation ...

Can someone who knows what they are on about (RobW#70 for example) please contribute to this thread, I’d take most of what HE says regarding bikes as dogma …

[yorkie_chris]

You miss my point, I don't really care either way, I've seen clearances open, I've seen them close, all I want to see is them back in the middle of their operating range.
No need to call me a knobber about it.

[Blue_SV650S]

You miss my point, I don't really care either way, I've seen clearances open, I've seen them close, all I want to see is them back in the middle of their operating range.
No need to call me a knobber about it.

Why the hostility then? :smt104

[yorkie_chris]

Was supposed to be in humour, honest

[Blue_SV650S]

Was supposed to be in humour, honest

Ha frekin ha!!! :p

[timwilky]

Now I may be talking out of my rear end here, and if this is the case please ignore as it may not apply to the simple SV engine.


Cam followers/buckets call them what you want, are designed to rotate within the carrier, this is to reduce wear, if they don't rotate a grove would be worn into the follower by the cam always rubbing against the same spot.

To induce this rotation, cams are very slightly tapered.


Therefore, you can expect there to be a minuscule difference between the gap when measured on the extreme ends of the lobes.

I have spent weeks using high speed photography to film cams/followers, seen the followers stick, seen the wear groves etc. Rotation is an important part of the cam system. It may just not be designed into the SV engine

[rictus01]

Now I may be talking out of my rear end here, and if this is the case please ignore as it may not apply to the simple SV engine.


Cam followers/buckets call them what you want, are designed to rotate within the carrier, this is to reduce wear, if they don't rotate a grove would be worn into the follower by the cam always rubbing against the same spot.

To induce this rotation, cams are very slightly tapered.


Therefore, you can expect there to be a minuscule difference between the gap when measured on the extreme ends of the lobes.

I have spent weeks using high speed photography to film cams/followers, seen the followers stick, seen the wear groves etc. Rotation is an important part of the cam system. It may just not be designed into the SV engine

Hmmm, never measured an SV valve to see (I'll do that next chance I get to confirm), but have seen the rotation effect on other valves, also seen the thermal effect on ceramic valves and the reduced effect of titanium light weight valves to control valve flow at high rpms, the benefits of additives in both fuel and oil on valve temp/wear and carbon build up is another area of interest to (done some practical testing myself here) all a bit techi stuff, but good to associated with witnessed engine wear.

However for setting purposes on the SV set the gap mid range not at either extreme, for those who don't understand the thermal dynamic wear characteristics and want to I could explain more simply* although I’d expect most to understand that the exhaust valve train will run upto 250’ F hotter than the inlet.

And Blue……. Posting for effect again.


*(PM me if you like).

Cheers Mark.

[Spanner Man]

Morning all.
I have found that on most shim & bucket engines all clearances tend to close up, this seems to be particularly prevalent on inlet valves, as I seem to shim more inlets than exhausts, on all makes & models.
Valve seat wear, & the valve stem stretching mostly contribute to the clearance lessening, whereas wear on the camshaft bearings, & the bucket & shim itself would contribute to the clearance increasing. On a well maintained engine the former is much more likely.
If a valve clearance is out of tolerance it need correcting period! On an SV where one can remove the camshafts individually, any camshafts that have both clearances within spec I tend to leave alone.
On something such as a ZX6 or 9 which have a one piece bearing which retains both camshafts, one would be daft not to re shim any valves that were virtually at either end of the specified tolerance.
A point of note, Kawasaki sent out a flyer to all dealers in the mid nineties which stated that when shimming valves, shim to the upper end of the specified tolerances, which has always been my preferred option, as for every valve I've seen go over tolerance, I have seen at least fifty go under.
Shims from most nineties Hondas (CB500, CBR6, Fireblade etc) are identical to the SV's, & also come in .025 increments. So if you can't get a Suzuki shim, your local Honda dealer may be able to help.

Cheers.

[Blue_SV650S]

....

Thanks spannerman for your informed (and independent) post, that is just what we needed here :study: :thumright:

So in conclusion, learned/observed FACT:- gaps do ALL close (unless there is something wrong), also Kawasaki suggested at one point shimming to the larger end of tolerance for this reason.

So back to where we came in, to me if you are buying shims and taking on this (not the most pleasant) job; then why not shim on the bigger gap side of tolerance to increase interval where it needs to be done again??? To my mind, the only time it is worth shimming close is if it is a race engine, where every fraction of a HP maters (that little bit more lift) and where it is in bits so often anyway!!!!! :D

[rictus01]

:laughat: selective reading and writing the word FACT aren't by any means supportive, but then you knew that.

All valves don't close over time & wear, no matter how much bold type you use.

Kawasaki's flyer of the mid 90's was sent out because there workshop manuals of that time gave direction to set mid range (as do most current manufacturers).

good bit of misdirection with the races engine part I'll grant you.

[Spanner Man]

Handbag chucking time folks!
I actually said MOST valve clearances reduce over time on a shim & bucket engine, & Kawasakis flyer was sent out for the reason that as MOST clearances close over time it would presumably be better to set them to the max. After all, they build the FECKIN things! (& it's 'their' manuals, & not 'there') MIAOWW!.:D

The only situation on a healthy engine that would generally cause the clearances to increase, would be an excessive build up of carbon on the valves, due to short journeys, or prolonged idling etc.....What reason do you think a single valve can increase it's clearance? Granted they can, one in fifty are my findings, as I've stated.

I don't think that Blue was miss directing, with his observations regarding racing engines, fact actually!

Cheers.

[Blue_SV650S]

....

I agree, using the term ALL is open to interpretation. By ALL I meant both inlet and exhaust valves gaps will tend to close (if everything else is in order/healthy), but then everyone knew that right as it is what I have been saying all along? I too have had gaps open, but its only because of other problems – normal/healthy running engines I have worked on, the gaps tend to close.

Rictus, your tone lends itself to me thinking you are obviously just spoiling for a (textual) rumble, I don’t really know why? :?

[rictus01]

I agree, using the term ALL is open to interpretation. By ALL I meant both inlet and exhaust valves gaps will tend to close (if everything else is in order/healthy), but then everyone knew that right as it is what I have been saying all along? I too have had gaps open, but its only because of other problems – normal/healthy running engines I have worked on, the gaps tend to close.

so ALL ment MOST, glad that's cleared up ;)

Rictus, your tone lends itself to me thinking you are obviously just spoiling for a (textual) rumble, I don’t really know why? :?


Just clarity.

Handbag chucking time folks!
I actually said MOST valve clearances reduce over time on a shim & bucket engine,

Indeed you did and I'd agree most do.

& Kawasakis flyer was sent out for the reason that as MOST clearances close over time it would presumably be better to set them to the max. After all, they build the FECKIN things!

I doubt there was any presumably about it, I don't know, but normally manufacturer amendments are in response it a problem in the original setup specs which is why they give an acceptable range, it doesn't necessarily mean all (not most ;)) manufacturers recommend it for all their bikes.

(& it's 'their' manuals, & not 'there') MIAOWW!.:D!

apologies, amendment accepted :D

The only situation on a healthy engine that would generally

the only or generally ?

cause the clearances to increase, would be an excessive build up of carbon on the valves, due to short journeys, or prolonged idling etc.....

whilst a carbon built up is indeed a possibility, I wouldn't address it by shimming it out as this is only masking the problem, if the engine looked to be in this condition, if minor I'd use additives or if needed strip it down and clean it properly, but then I'm sure you'd do the same.

What reason do you think a single valve can increase it's clearance? Granted they can, one in fifty are my findings, as I've stated.!

I was vexed by this for a while also, however upon investigation (source was a Mclaren engineer) was told the inlet valve train runs at between 150' F - 250' F cooler that the exhaust temperature (which remains predominantly stable), this in turn lead to the same components of either side valve train wearing at different rates, and can result in greater clearance, they call it thermal dynamic wear patten.

having actually seen greater clearances on engine that didn't appear to have any other problems (although a history of fuelling changes could well shed light on it), this seemed more than plausible to me, in these cases I would shim it back to spec.


I don't think that Blue was miss directing, with his observations regarding racing engines,

Come on now, race engines are generally perseved to be a high preformace, to that end have a far greater amount of time and effort ( not to mention money) spent on them, you can indeed set tollerances tighter and remove the manfacturing slackness from them, but you also need to up the service schedule to match, I can't see many people stripping the engine after a trip in to work :eek:

fact actually!

Can't be fact, you haven't used BOLD
;)


Cheers Mark.

[toonyank]

You miss my point, I don't really care either way, I've seen clearances open, I've seen them close, all I want to see is them back in the middle of their operating range.
No need to call me a knobber about it.

Exactly, go for the nominal and besides at that age of bike it's not likely of much more wear to the valve seats. After all the more they smack the more they work harden and shouldn't be a problem from hear on after this it's more likely valvetrain wear which will increase gap which is not a danger situation it's when they don't seat (no gap or worse negative gap) that exhaust valves burn.

[Spanner Man]

Morning all.
Oh dear the handbags are flying! Good fun though eh!

Enough of this churlishness, let's all hold hands & agree that MOST valve clearances will close up over time. Hence when shimming it would be wise to set the clearances to the mid way point of the tolerance at least. (I'll still set them nearer the maximum:p).

I have a suspicion that as petrol has changed considerably over the last 20 years, it has contributed to the fact that inlet valves close up more readily than they used to, for back in the seventies & eighties, indeed it was more common to have to adjust exhaust valves as opposed to inlet valves. But, as I've stated I have found the opposite to be the case over the last 10 years or so.
Still on the subject of petrol, I have found that engines that are run on normal unleaded from one of the major companies, (Esso, Total, etc), suffer less in the way of carbon build up on the valves, than those that are run on cheapo muck from the Supermarkets etc.
I have always used Forte fuel system cleaner on engines that have heavy carbon deposits on the valves. I've seen valve clearances reduce by as much as .07mm after an application, & a good run. I don't think it's available now, as it probably contained something that the greenies managed to get banned.

Comparing race engines to road engines is usually of little relevance,(as is quoting Maclaren engineers) but the point Blue made regarding them is most definitely valid. & of course it wouldn't be practical to strip ones engine down after a trip to work!

Anyway, enough of this points scoring:D, I'm off to give a troublesome Bandit what for!

Cheers.

P.S. My English is much better that yours Rictus old bean INNIT!!!!:D:D

[Blue_SV650S]

...

Just ignore him, read his posts to most people, I tend to think they are generally rude and demeaning, rarely actually THAT helpful. :smt018

Thanks for your input - hope you get that bandit tamed!! :D

[Spanner Man]

Just ignore him.....

Thanks for your input - hope you get that bandit tamed!! :D

My sentiment exactly!:D, then again I usually do that when people can't spell:D:D

Bandit already beaten into submission! Now to set it's tappets, & being an engine with screw & locknut adjusters I shall set them to the MIDDLE of the recommended tolerance, as on engines with this type of valvegear clearances can go EITHER way in EQUAL proportions!!!!!!!!!!!!:D

There's a cue for some Backstreetaintgotafeckincluemate type to sling HIS or HER handbag into the ring, if ever I saw one!:D:D:D

Cheers.

Spiffing fun this cyber banter isn't it?

[yorkie_chris]

Was never expecting this thread to turn into a "light fuse, run away" type!

[Spanner Man]

Morning all.
Us professional types on here do tend to get forceful when another questions ones findings & opinions. But hey, conversation was invented for the exchange of ideas & information etc.
A bit of good old handbag chucking brightens the day somewhat eh! I can't speak for the others, but I don't take it seriously.

Cheers.

[Sid Squid]

Just ignore him, read his posts to most people, I tend to think they are generally rude and demeaning, rarely actually THAT helpful. :smt018

Really? I think you'll find that Rictus has added and done more for this forum and it's users than any other single individual. Including actually spending his own time and effort to assist.

[Spanner Man]

Afternoon all.
HMMMMM!! Look like you Southern types sticking together Sid:D & of course no one else on here does a thing for anyone do they?

And you're not of course posting for effect then eh!

Cheers.

[Sid Squid]

Having been a member for some while I actually KNOW the above to be true.

No element of Southern sticking together, (is Blue not Dahn Sarf as well), just speaking as I find.

A ridiculous slanging match has no place here, no-one who entered one ever comes out of it looking good, and as one of the respondents you might think on that too.

PS. As someone who has a liking for good spelling and grammar I have sometimes pointed out mistakes, however to suggest that someones knowledge or findings is less applicable because of spelling errors is quite daft. I do hope no-one that would do that ever slips up themselves and thus be hoist by their own...

[Spanner Man]

PS. As someone who has a liking for good spelling and grammar I have sometimes pointed out mistakes, however to suggest that someones knowledge or findings is less applicable because of spelling errors is quite daft. I do hope no-one that would do that ever slips up themselves and thus be hoist by their own...

Good afternoon all.
I see that the sense of humour bypass was a success Sid old chap!:D

I don't think it's a geographical issue actually, (I think it's the 'home twiddler brigade' bigging themselves up).:D

I don't see it as a slanging match, more like good natured banter actually, but then again I do have a sense of humour, (& I too originate from down south & indeed spell it correctly):D

An individuals spelling or grammar obviously has no bearing on their understanding of any subject (except English). I was under the impression that these little smiley faces were there to indicate that one was jesting, & of course one would have to be careful not to make errors oneself for one would indeed be hoist (ED) by ones own Petard, as the saying goes.

Cheers.

[MR UKI (1)]

Start another 'Which oil?' thread Spannerman, you know you want too :D

[Spanner Man]

Good afternoon UKI old boy!

Nah, that last one is still way too fresh:D.
It seems that there's a growing number of 'dummychuckingknowalls' on here lately, who mistake good natured banter as something more serious:D.

But us good humoured types will have the last laugh, as they'll be wearing triple thickness bottle bottom glasses from all that looking down their noses at people:smt110:smt110:smt110.

Cheers.

[rictus01]

Away for a while and look what I miss.

[northwind]

Away for a while and look what I miss.

You must be gutted about that :D

[Spanner Man]

Morning all.
As Northwind says, you must indeed be gutted, & there was me thinking that I'd finally shut you up, only to find that you had been away! Try harder next time methinks!:D

Cheers.

[Sid Squid]

Last word competition won by - Me!