Kawasaki ZX-10R Forum banner

1 - 18 of 18 Posts

·
Registered
Joined
·
407 Posts
Discussion Starter #1
I just inspected my valve this morning on my 06 zx10 and they are a little loose.
I know the tolerance for the Ex is .17 - .22mm or .0067 - .0087in and for
the intake it is .15 - .24mm or .0059 - .0094in.

My question is where in that range should I be.

The bike is only used for track and race so no street miles. The bike is production so there is no special components.

I have called a few places some say go with the middle of the range while others are saying to go closer to the tight side.

I can see the benefits to both so any input would be very helpful

Thanks in advance
 

·
Registered
Joined
·
1,797 Posts
I might be wrong on this but as a machinist I would think that as long you are within the high and low of your tolerances you should be ok. In the machine shop world thats why you have tolerance. Also if I understand things correctly the valves in this engines get tight over time instead of loose due to valveseat wear,....again not sure?:dontknow:
 

·
Registered
Joined
·
407 Posts
Discussion Starter #3
I might be wrong on this but as a machinist I would think that as long you are within the high and low of your tolerances you should be ok. In the machine shop world thats why you have tolerance. Also if I understand things correctly the valves in this engines get tight over time instead of loose due to valveseat wear,....again not sure?:dontknow:
I have heard that usually it is supposed to get tight too which is another thing that is throwing me off. I'm mostly curious as to weather on side of the spectrum is better than another for road racing or if I should shoot for the middle. I was told that the shims might be starting to compress witch would cause the loose fit. I don't know.
 

·
Registered
Joined
·
1,797 Posts
I have heard that usually it is supposed to get tight too which is another thing that is throwing me off. I'm mostly curious as to weather on side of the spectrum is better than another for road racing or if I should shoot for the middle. I was told that the shims might be starting to compress witch would cause the loose fit. I don't know.
I think the shims are made of really hard forged material, if so seems they would break before compressing. It throws me off about the valves getting tight also,I have been told the valve angle and the valve seat wears causing the the valve to press farther into the head closing the clearance between the cam and the valve................
 

·
Registered
Joined
·
598 Posts
If I were you I would keep them within spec and try to get them consistent. i.e. all of the intakes at similar tolerances and all of the exhaust valves at similar tolerances. As long as you are in spec I do not think you are gaining anything by being tight or loose. I would shoot for the middle. I know for a race bike you do not want them too tight since this can cause your valves to overheat and fail.
 

·
Registered
Joined
·
407 Posts
Discussion Starter #6
I think the shims are made of really hard forged material, if so seems they would break before compressing. It throws me off about the valves getting tight also,I have been told the valve angle and the valve seat wears causing the the valve to press farther into the head closing the clearance between the cam and the valve................
I think I need to check the buckets also to make sure that the cam hasn't worn into the causing them to be recessed. Also under advice from a buddy at work I am going to run a leak down and compression test to see if maybe the valves are gummed up which may cause them to be loose. I haven't noticed a lack of power but better to do it right than wonder once it is back together
 

·
Registered
Joined
·
407 Posts
Discussion Starter #7
If I were you I would keep them within spec and try to get them consistent. i.e. all of the intakes at similar tolerances and all of the exhaust valves at similar tolerances. As long as you are in spec I do not think you are gaining anything by being tight or loose. I would shoot for the middle. I know for a race bike you do not want them too tight since this can cause your valves to overheat and fail.
If there is nothing to gain from it then I will just go for the middle.
Is it friction from them being tight which would cause them to overheat and fail? I am definitely trying to avoid failure, but if they are within spec just on the tight side would it be a noticeable difference in heat or failure?
I also know that loose tolerances tend to wind up faster so I don't know if that may prove a factor in my decision.
 

·
Registered
Joined
·
29 Posts
Kawi race manual says that more power is expected if the valveclearances are set to "upper" range. Does that mean valveclearances should be loose?
I did set mine loose side. Intakes are now average 0,20mm and ex are average 0,22mm. I do lot of trackdays, so i decided to adjust like this mentioned.
 

·
Registered
Joined
·
598 Posts
My understanding is that if the valves are too tight they can not cool properly and they overheat and bend/fail. I think this is due to the constant contact with the valve train. A bit of separation allows for more oil to cool the valve and surrounding components.
 

·
Registered
Joined
·
1,797 Posts
My understanding is that if the valves are too tight they can not cool properly and they overheat and bend/fail. I think this is due to the constant contact with the valve train. A bit of separation allows for more oil to cool the valve and surrounding components.
Also if they are too tight they will not seat completely causing a loss of compression and could burn the exhaust valves do to combustion blowing through the valve giving it a cutting torch effect.
 

·
Registered
Joined
·
1,361 Posts
valve tolerances

valves dont loosen up unless tweaked by contact. valves tighten up from valve stretch, seat wear,valve cupping , or keepers pulling through retainers. high spring pressure as in hd springs quickens all these. some springs for the 10 are downright dangerous to run because of acellerated valve train wear. shims dont shrink, or break in normal operation, they are tool steel. some are even hard coated. buckets dont wear or gall with normal oiling and spring pressure. if you dont know it, ex. valves operate white hot in high load situations for hours at a time. valves need very , very little oil by the oil seal, and they cool primarily by contact with the valve guide, and seat, both shedding their heat into the alum. head. as far as clearances, within spec. is fine. each at exactly the same bettter. valves loose allow a little more time to transfer heat to valve seat and seal time. balanced, in the middle is my personal preference, and my engine doesnt sound like a combine running. initial seating is a natural process, todays valvetrains are so good there is very little of that. adjust your valves and let it rip.
 

·
Registered
Joined
·
407 Posts
Discussion Starter #12
Kawi race manual says that more power is expected if the valveclearances are set to "upper" range. Does that mean valveclearances should be loose?
I did set mine loose side. Intakes are now average 0,20mm and ex are average 0,22mm. I do lot of trackdays, so i decided to adjust like this mentioned.
This is good info I would assume upper range would be loose clearance

Also if they are too tight they will not seat completely causing a loss of compression and could burn the exhaust valves do to combustion blowing through the valve giving it a cutting torch effect.
I'm not intending to make them that tight I was just trying to figure out which side of the spectrum (within the tolerance) would be best

valves dont loosen up unless tweaked by contact. valves tighten up from valve stretch, seat wear,valve cupping , or keepers pulling through retainers. high spring pressure as in hd springs quickens all these. some springs for the 10 are downright dangerous to run because of acellerated valve train wear. shims dont shrink, or break in normal operation, they are tool steel. some are even hard coated. buckets dont wear or gall with normal oiling and spring pressure. if you dont know it, ex. valves operate white hot in high load situations for hours at a time. valves need very , very little oil by the oil seal, and they cool primarily by contact with the valve guide, and seat, both shedding their heat into the alum. head. as far as clearances, within spec. is fine. each at exactly the same bettter. valves loose allow a little more time to transfer heat to valve seat and seal time. balanced, in the middle is my personal preference, and my engine doesnt sound like a combine running. initial seating is a natural process, todays valvetrains are so good there is very little of that. adjust your valves and let it rip.
Will do sounds good. I think I will double check sense they seem to be on the loose side I don't want to let it rip if something is bent
 

·
Registered
Joined
·
1,361 Posts
valves

a very small tweak in valve head trueness, produces big clearences, and leakdown., and a ticking valve, usually pretty audible. cking valves on different engines is like opening a box of chocolates, you never know what you will find. usually they are fairly consistent, within a couple thous. either way tight or loose, sometimes more. doesnt mean anything is wrong, but as you mentioned, since you are racing and want it all, leak it and you can be absolutely sure. mid to upper limits for your purpose. expensive from kaw, list for 14.00 each, hot cam a good option and i have about 30 extra if u need help. often shim size cant be read, must use mike to select new shim. its smart to ck and set things right, good racing.
 

·
Registered
Joined
·
1,483 Posts
gazx10 is right on IMHO.

The race manual suggestion is to set lash close to the TIGHT side, which gives more lift and duration. If it's a race motor, tight is fine as long as it's within the range.
 

·
Registered
Joined
·
226 Posts
Over time, the valve seats wear and the valve lash gets tighter. Set it toward the large side so they'll stay within tolerance longer. The very small difference in lift between the high and low end of the clearance tolerance is inconsequential for performance.
 

·
Registered
Joined
·
29 Posts
I have here Yamaha R6 Kit Manual, it states:

INT race 0,17-0,23
INT std 0,11-0,20

EXT race 0,27-0,33
EXT std 0,21-0,30
 

·
Registered
Joined
·
226 Posts
I have here Yamaha R6 Kit Manual, it states:

INT race 0,17-0,23
INT std 0,11-0,20

EXT race 0,27-0,33
EXT std 0,21-0,30
I expect race is wider to accommodate higher wear rates and temperature, not to make the bike go faster.
 

·
Registered
Joined
·
1,483 Posts
Do what makes you comfortable. It's a common practice to set valve lash tight for a bit more lift and duration. Ask a Supersport racer.

KHI race manual:

Adjust the valve clearance within the specified value. Intake: 0.15 ~ 0.24 mm, Exhaust: 0.17 ~ 0.22 mm

More performance is expected when adjusted from middle value to upper limit between
adjustable range.
 
1 - 18 of 18 Posts
Top