Valves and tolerances

Ron1000 · 09-10-2020, 03:16 PM

See if I can annoy everybody instead of just Mr Gazza with this next one

Valve clearances ON MY R6 TRACK BIKE - mods delete if necessary

So obvs very different to a Ducati, pretty straight forward for the most part and I’m definitely overthinking this however.

With regards to tolerances my R6 (exhaust side as an example) is 0.21 to 0.30mm. So I read that as 0.21mm is the loosest the valve should be and 0.30 is the tightest the valve should be. My logic being 0.21 clearance would give the lobe maximum opening time and 0.30 would give the lobe minimum opening time.

I look forward to your thoughts and my imminent ban

slob · 09-10-2020, 03:31 PM

back to front Ron. you’re right about opening times but that’s just a side effect. Opening and closing times are usually stated at a given valve lift (eg 1mm) to take clearances out of the equation, since you should be measuring on a stone cold engine. 0.2mm is the minimum clearance and 0.3mm the maximum... just as it sounds. Once warm (bloody hot) the parts have expanded and lost around 0.2mm of clearance, so it’s ideal at zero, the engine can live with 0.1mm of free play without too much of a hit. What you really don’t want is less than the minimum 0.2mm, as this means once warmed up the valve will never fully seat when ‘off cam’ losing compression and adversely affecting performance.

Ron1000 · 09-10-2020, 03:41 PM

Perfect slob. Nice. Yeah it seems the valves are too tight…not measured yet, awaiting correct tool. The engine becomes noisy and hard to start when hot. A classic symptom in these yams apparently.

I’ll just make sure they are set back to between the tolerances and leave it alone

The precision type in me would dearly like them to be all exactly the same e.g. 0.25mm but I’ll not push my luck.

slob · 09-10-2020, 03:51 PM

Aiming for the middle of the range is good. It stops you worrying about minor measuring errors. Also worth remembering that the cams/shims/buckets/valves aren’t what wears, it’s the seats, so the valves gradually recede into the heads, reducing clearances.

the lodger · 09-10-2020, 07:14 PM

My simple understanding of valve clearances is like this ( caveat I know nothing about Yams ) . What Slob said:

1. clearances tend to close up so 0.3 moves towards 0.2 and not the other way round
2. So a clearance at the upper end of the range (0.3) is ok but one at the lower end ( 0.2) may need actioning if it is near 0.2 or less
3. Bigger clearances (0.3) are better for longer valve life
4. Tighter clearances ( 0.2 ) are better for power
5. 3 and 4 above are relative , marginal and not something to aim for as any clearance in range ( 0.2 to 0.3 ) is ok

Note the clearances and shim measurements you have. Sometimes you can just swap over shims to get back in range.

Good luck

Ron1000 · 09-10-2020, 07:44 PM

Thanks lodger. I’m hoping for minimal adjustments as the shims are £11 each and there’s 16 of them.

Oh and side issue Yamaha reliability is a myth, yamaha did not continue the water jacket all the way round the cylinders on this particular model and apparently the cylinder liners will crack eventually on every single bike. Could be 1 mile could be 50k miles.

Terrible terrible design work, apparently they fixed it in later models then added other issues that make them just as bad.

I’m now looking at my 1100 Evo even more lovingly now.

Ron1000 · 13-10-2020, 08:36 PM

Any ideas on this one guys:

So Yamaha list shim size as 120, 125, 130 etc up to 210. So I’ve got the shims out and two or three are marked as 172 etc, according to yamaha this shouldn’t even exist.

Now worried that someone has done reasonably extensive engine mods.

Any thoughts welcome.

the lodger · 13-10-2020, 09:31 PM

Ron
You should treat anything marked on a shim as a helpful guide to what size it might be but in practice you should measure them with a micrometer to check and confirm. They don't wear much but they do wear. Re the odd size found you could use any shim for the job
( so not necessarily a "Yamaha " one ) if it is the right size for the job

Ron1000 · 13-10-2020, 09:55 PM

Yeah that’s fine but it kind of puts me in no mans land with sizing.

The 172 (stamped on it not measured) shim was never fitted in the factory absolutely guaranteed. So just wondering where it came from, why and possible problems. As it essentially puts me in the position of going to a 170 then using the shim Calc table from there. If you know what I mean.

Or calculate it and find weird shim sizes which is at odds with what Yamaha say to do.

Luddite · 13-10-2020, 10:06 PM

Is this thread any help, Ron?

http://fzronline.com/forum/viewtopic.php?t=7807

Ron1000 · 15-10-2020, 10:27 AM

I’m back troops. Seems it’s all a bit easier than I thought, I was wrong (shocker) it is entirely possible Yamaha did fit weird factory sizes; two I’ve got are 148 and 172.

But they do give a wee table and an explanation on it. So basically you round up or down. 0 = 0, 3 = 5, 8 = 10 i.e. 148 = 150 and 172 = 170.

Then you use the table so depending on clearance you maybe go down to 165 or up to a 175.

I had it all perfect lastnight; buckets, shims all in and cam rail on (took an age as they are fragile and machined individually to each engine) all timed up perfectly…then the chain slipped and timing was out so had to strip it all back to re-align the timing. I’ll have it all back together tonight hopefully.

09-10-2020, 03:16 PM	#1
Ron1000 Registered User Join Date: Jun 2015 Location: Livingston Bike: M1100evo Posts: 863	Valves and tolerances See if I can annoy everybody instead of just Mr Gazza with this next one Valve clearances ON MY R6 TRACK BIKE - mods delete if necessary So obvs very different to a Ducati, pretty straight forward for the most part and I’m definitely overthinking this however. With regards to tolerances my R6 (exhaust side as an example) is 0.21 to 0.30mm. So I read that as 0.21mm is the loosest the valve should be and 0.30 is the tightest the valve should be. My logic being 0.21 clearance would give the lobe maximum opening time and 0.30 would give the lobe minimum opening time. I look forward to your thoughts and my imminent ban

09-10-2020, 07:14 PM	#5
the lodger Registered User Join Date: Oct 2019 Location: Chorley Bike: M900 Posts: 160	My simple understanding of valve clearances is like this ( caveat I know nothing about Yams ) . What Slob said: 1. clearances tend to close up so 0.3 moves towards 0.2 and not the other way round 2. So a clearance at the upper end of the range (0.3) is ok but one at the lower end ( 0.2) may need actioning if it is near 0.2 or less 3. Bigger clearances (0.3) are better for longer valve life 4. Tighter clearances ( 0.2 ) are better for power 5. 3 and 4 above are relative , marginal and not something to aim for as any clearance in range ( 0.2 to 0.3 ) is ok Note the clearances and shim measurements you have. Sometimes you can just swap over shims to get back in range. Good luck __________________ Contents may settle !

13-10-2020, 09:31 PM	#8
the lodger Registered User Join Date: Oct 2019 Location: Chorley Bike: M900 Posts: 160	Ron You should treat anything marked on a shim as a helpful guide to what size it might be but in practice you should measure them with a micrometer to check and confirm. They don't wear much but they do wear. Re the odd size found you could use any shim for the job ( so not necessarily a "Yamaha " one ) if it is the right size for the job __________________ Contents may settle !

09-10-2020, 03:31 PM	#2
slob . Join Date: Jul 2003 Location: East London Bike: Multiple Monsters Posts: 9,707	back to front Ron. you’re right about opening times but that’s just a side effect. Opening and closing times are usually stated at a given valve lift (eg 1mm) to take clearances out of the equation, since you should be measuring on a stone cold engine. 0.2mm is the minimum clearance and 0.3mm the maximum... just as it sounds. Once warm (bloody hot) the parts have expanded and lost around 0.2mm of clearance, so it’s ideal at zero, the engine can live with 0.1mm of free play without too much of a hit. What you really don’t want is less than the minimum 0.2mm, as this means once warmed up the valve will never fully seat when ‘off cam’ losing compression and adversely affecting performance.

09-10-2020, 03:41 PM	#3
Ron1000 Registered User Join Date: Jun 2015 Location: Livingston Bike: M1100evo Posts: 863	Perfect slob. Nice. Yeah it seems the valves are too tight…not measured yet, awaiting correct tool. The engine becomes noisy and hard to start when hot. A classic symptom in these yams apparently. I’ll just make sure they are set back to between the tolerances and leave it alone The precision type in me would dearly like them to be all exactly the same e.g. 0.25mm but I’ll not push my luck.

09-10-2020, 03:51 PM	#4
slob . Join Date: Jul 2003 Location: East London Bike: Multiple Monsters Posts: 9,707	Aiming for the middle of the range is good. It stops you worrying about minor measuring errors. Also worth remembering that the cams/shims/buckets/valves aren’t what wears, it’s the seats, so the valves gradually recede into the heads, reducing clearances.

09-10-2020, 07:44 PM	#6
Ron1000 Registered User Join Date: Jun 2015 Location: Livingston Bike: M1100evo Posts: 863	Thanks lodger. I’m hoping for minimal adjustments as the shims are £11 each and there’s 16 of them. Oh and side issue Yamaha reliability is a myth, yamaha did not continue the water jacket all the way round the cylinders on this particular model and apparently the cylinder liners will crack eventually on every single bike. Could be 1 mile could be 50k miles. Terrible terrible design work, apparently they fixed it in later models then added other issues that make them just as bad. I’m now looking at my 1100 Evo even more lovingly now.

13-10-2020, 08:36 PM	#7
Ron1000 Registered User Join Date: Jun 2015 Location: Livingston Bike: M1100evo Posts: 863	Any ideas on this one guys: So Yamaha list shim size as 120, 125, 130 etc up to 210. So I’ve got the shims out and two or three are marked as 172 etc, according to yamaha this shouldn’t even exist. Now worried that someone has done reasonably extensive engine mods. Any thoughts welcome.

13-10-2020, 09:55 PM	#9
Ron1000 Registered User Join Date: Jun 2015 Location: Livingston Bike: M1100evo Posts: 863	Yeah that’s fine but it kind of puts me in no mans land with sizing. The 172 (stamped on it not measured) shim was never fitted in the factory absolutely guaranteed. So just wondering where it came from, why and possible problems. As it essentially puts me in the position of going to a 170 then using the shim Calc table from there. If you know what I mean. Or calculate it and find weird shim sizes which is at odds with what Yamaha say to do.

13-10-2020, 10:06 PM	#10
Luddite Registered User Join Date: Aug 2011 Location: Southampton Bike: M1100evo Posts: 2,465	Is this thread any help, Ron? http://fzronline.com/forum/viewtopic.php?t=7807

15-10-2020, 10:27 AM	#11
Ron1000 Registered User Join Date: Jun 2015 Location: Livingston Bike: M1100evo Posts: 863	I’m back troops. Seems it’s all a bit easier than I thought, I was wrong (shocker) it is entirely possible Yamaha did fit weird factory sizes; two I’ve got are 148 and 172. But they do give a wee table and an explanation on it. So basically you round up or down. 0 = 0, 3 = 5, 8 = 10 i.e. 148 = 150 and 172 = 170. Then you use the table so depending on clearance you maybe go down to 165 or up to a 175. I had it all perfect lastnight; buckets, shims all in and cam rail on (took an age as they are fragile and machined individually to each engine) all timed up perfectly…then the chain slipped and timing was out so had to strip it all back to re-align the timing. I’ll have it all back together tonight hopefully.