KZScott
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posted April 28, 2010 05:44 PM
how do you check for bent valves?
let me first say Ive never done it, but I do catch on pretty quick with an explanation 
Im not sure if what I have done is correct, I was just guessing. I made 2 blocks out of 1.5x1.5in angle aluminum. with the open end down(point up), i cut a "V" notch in the top of each. I put a valve resting across the blocks so it was free to spin in the notchesI put one end very close to where the collets go, and the other very close to the valve head. I pit the DI in the middle pushing the valve into the blocks. very very carefully i spun the valves and watched the DI. I had an analog DI accurate to .0001 " got very reproducible results. the worst exh valve had about .00005 travel. one mark on the DI to halfway to the next and back on a full rotation. 2 more had slightly less about a third vs halfway, and 2 intakes had maybe a third aswell. the rest were rock solid, no bend.
what concearns me is that the valves could be bent further towards the head and this test would not show it. Im also not sure how much, if any bend is acceptable?
the reason I checked the valves was because the exh were just nicking the edge of the valve pockets on my pistons. I saw no contact on the intake side however.
____________
01 ZX-12R 8.84 @ 156.3 no bars, DOT tires. Pump Gas, NA.... turbo 8.47 @ 164.
00 ZX-12R 8.62 @ 165.2 no bars, slicks, Pump Gas, 55 shot.... turbo 8.32 @173
00 ZX-12R Fastest NA Kawasaki in the world 1: 222.046 1.5: 226.390 Loring AFB
00 ZX-12R street turbo 1: 227.9 1.5: 234.1 Loring AFB
00 ZX-12R LSR turbo 1: 263.1 1.5: 266.5 Loring AFB Worlds fastest ZX-12R
CMG Racing RCC Turbos
  
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ZRXDean
Needs a job
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posted April 28, 2010 07:02 PM
I put them in a drill press and turn it on
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Ozonkiller
Expert Class
Posts: 350
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posted April 28, 2010 10:44 PM
First question is, Why did you pull it down?
Usually valves bend right at the head. The stem may show straight but if the head of the valve wobbles you're toast. Use some machinists blueing on the valve face and see if it makes 360 degrees contact on the valve seat.
Half a tenth ain't much but since you're in there, why not play it safe. It's possible for an exhaust valve to hit, bend and then straighten back again if it's hot enough, but it will be weakened.
You've got to screw up awfully bad to bend an intake.
Sorry if I put the fear of B'Jeezus in you but all I can say is "If it was me, I'd change 'em"
I'm playing the devil's advocate here. I might think differently if I saw it in person.
Good luck,
Tom
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KZScott
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posted April 29, 2010 06:21 PM
quote:
I put them in a drill press and turn it on
with a DI?
____________
01 ZX-12R 8.84 @ 156.3 no bars, DOT tires. Pump Gas, NA.... turbo 8.47 @ 164.
00 ZX-12R 8.62 @ 165.2 no bars, slicks, Pump Gas, 55 shot.... turbo 8.32 @173
00 ZX-12R Fastest NA Kawasaki in the world 1: 222.046 1.5: 226.390 Loring AFB
00 ZX-12R street turbo 1: 227.9 1.5: 234.1 Loring AFB
00 ZX-12R LSR turbo 1: 263.1 1.5: 266.5 Loring AFB Worlds fastest ZX-12R
CMG Racing RCC Turbos
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KZScott
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Posts: 7235
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posted April 29, 2010 06:26 PM
quote:
First question is, Why did you pull it down?
Usually valves bend right at the head. The stem may show straight but if the head of the valve wobbles you're toast. Use some machinists blueing on the valve face and see if it makes 360 degrees contact on the valve seat.
Half a tenth ain't much but since you're in there, why not play it safe. It's possible for an exhaust valve to hit, bend and then straighten back again if it's hot enough, but it will be weakened.
You've got to screw up awfully bad to bend an intake.
Sorry if I put the fear of B'Jeezus in you but all I can say is "If it was me, I'd change 'em"
I'm playing the devil's advocate here. I might think differently if I saw it in person.
Good luck,
Tom
tear down for upgrades, bike was running fine(better than ever actually, but i still found a lot of issues). noticed the exh valves were nicking the valve pockets. the intakes have never hit anything and are stock, exh are 1mm os SS
my head is in another country right now so i cant try machinists blueing for awhile
____________
01 ZX-12R 8.84 @ 156.3 no bars, DOT tires. Pump Gas, NA.... turbo 8.47 @ 164.
00 ZX-12R 8.62 @ 165.2 no bars, slicks, Pump Gas, 55 shot.... turbo 8.32 @173
00 ZX-12R Fastest NA Kawasaki in the world 1: 222.046 1.5: 226.390 Loring AFB
00 ZX-12R street turbo 1: 227.9 1.5: 234.1 Loring AFB
00 ZX-12R LSR turbo 1: 263.1 1.5: 266.5 Loring AFB Worlds fastest ZX-12R
CMG Racing RCC Turbos
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rtbain
Expert Class
old, fat and slow
Posts: 244
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posted May 01, 2010 02:54 PM
quote:
I put them in a drill press and turn it on
Man, I really hate it when some goes up with a simple, elegant solution. Especially when I didn't think of it first.
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Randy
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Ozonkiller
Expert Class
Posts: 350
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posted May 02, 2010 08:15 AM
Better be a good drill press
A mill of a lathe might work. V Blocks are guaranteed to have NO run out
Tom
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KZScott
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posted May 02, 2010 02:14 PM
so I tried 3 different drill presses today, all wobbled.
how do you check with v blocks? anyone have pics?
____________
01 ZX-12R 8.84 @ 156.3 no bars, DOT tires. Pump Gas, NA.... turbo 8.47 @ 164.
00 ZX-12R 8.62 @ 165.2 no bars, slicks, Pump Gas, 55 shot.... turbo 8.32 @173
00 ZX-12R Fastest NA Kawasaki in the world 1: 222.046 1.5: 226.390 Loring AFB
00 ZX-12R street turbo 1: 227.9 1.5: 234.1 Loring AFB
00 ZX-12R LSR turbo 1: 263.1 1.5: 266.5 Loring AFB Worlds fastest ZX-12R
CMG Racing RCC Turbos
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2000redrocket
Pro
Posts: 1662
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posted May 02, 2010 02:49 PM
the drill press is going to only be as good as it was designed. they are not mills.if the head has a wobble it is junk. put the indicator on the stem in the chuck.look at the stem runout and compair the head wobble. heck put a nother indicator on the valve face if you can get a nother.
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rtbain
Expert Class
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Posts: 244
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posted May 02, 2010 02:50 PM
Buy some v-blocks. Make sure you get them in pairs, this gives you better assurance of a matching set. I prefer steel. Not critical but let the valves and the v-blocks come to the same temperature.
Put the stem of the valve in the v of the block. Rotate the valve and check for run out. If the stem is straight the run out will be in the face portion of the valve. You might be able to tell visually, if not use a dial indicator.
____________
Randy
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Y2KZX12R
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posted May 02, 2010 03:28 PM
I'll give you the quick run down on the procedure and things to watch out for.
Buy a good steel machinist V block set. Like the SMB–1253 http://www.simranindustries.com/measuring_tools_2.html
This size v block allows the end of the valve where the keepers are to be hanging off the v block. It also allows the other end of the V block to be below the carbon line on the stem. The part of the stem that is never exposed to the port.
Buy a good dial indicator that reads .0001" increments. http://www.starrett.com/download/260_p139_145.pdf
you will need a base setup to hold it as well.
We clamp the v block on the table of the Bridgeport. But you will need to find a way to clamp the v block down so it doesn't move. Place the valve in the vblock and set up a back stop against the tip of the valve. you can use another clamped v block turned sideways or something heavy that doesn't move.
Set the dial indicator so that you can read the dial but the carbide ball and arm are perpendicular to the 45 valve face. This will give the most accurate reading.
You must clean the valves with a wire wheel. Get all deposits off.
use your index finger to keep the valve stem tight in the V and spin the valve by the head in the V block while keeping it tight against the back stop.
It takes a little practice to get smooth readings but you will get the hang of it quickly.
Most used valves have some run-out. I use .001" as a cutoff. anything over .0011" total run-out gets tossed in the junk bin. You may see valves with .002- .006" run-out. This doesn't mean they got bent from hitting a piston. Typically its warpage from heat and can be from valve bounce from seats that arent concentric.
Once you get the hang of it its very easy.
____________
Y2KZX12R
CompetitionCNC.com
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KZScott
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posted May 02, 2010 04:47 PM
 Edited By: KZScott on 3 May 2010 00:53
Jim, once again I thank you for your very valuable input!
I got setup like you advised, and did all my valves with no problems 
on the IN side I had two at less than .0001, one at .0002 and the rest around .0001. these are the stock valves that have been in the bike since it was new and have never shown any signs of hitting anything. I have a few spare IN and the first one I pulled out was .0001 I can replace the .0002 with, but now Im not sure if it would even matter all the valves looked like they had a nice uniform contact area with the seat
on the EX side I had a couple at less than .0001, the majority at .0001 and one at .0005(which worried me until I read that up to .0010 is ok just now)
these valves are 1mm over size SS that Jim installed last winter with matching over size bronze seats. these valves all nicked the edge of the valve pockets in my pistons due to excessive piston skirt to cylinder clearance(the face of the valve didnt actually smack the piston head on). something that has my attention is the fact that the contact area of the valve to seat is not a nice uniform line, rather "patchy" or "wavey". I assume this is from nicking the pistons or the valve seats moving?? car guys tell me they have to lap valves after a few heat cycles if they get new seats put in due to the seats moving a tiny bit to their final location(beat into place by the valves). Im not sure if this applies to this however
____________
01 ZX-12R 8.84 @ 156.3 no bars, DOT tires. Pump Gas, NA.... turbo 8.47 @ 164.
00 ZX-12R 8.62 @ 165.2 no bars, slicks, Pump Gas, 55 shot.... turbo 8.32 @173
00 ZX-12R Fastest NA Kawasaki in the world 1: 222.046 1.5: 226.390 Loring AFB
00 ZX-12R street turbo 1: 227.9 1.5: 234.1 Loring AFB
00 ZX-12R LSR turbo 1: 263.1 1.5: 266.5 Loring AFB Worlds fastest ZX-12R
CMG Racing RCC Turbos
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Y2KZX12R
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posted May 03, 2010 04:37 AM
Scott,it couls be from the valves hitting the pistons. We havent seen the bronze seats move on the bike heads. The springs dont have much seat pressure compared to the springs in a V8 race head.
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Y2KZX12R
CompetitionCNC.com
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KZScott
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posted May 03, 2010 01:13 PM
ok, I messed up reading the DI, I was off a decimal place. F*** 
the valve I said was at .0005 is really .0050. I was checking cam lift and caught the mistake.
so I need at least 1 exh valve
Jim, the guy from the kawi dealership is supposed to get back to me tonight. Ill let you know as soon as I know 
____________
01 ZX-12R 8.84 @ 156.3 no bars, DOT tires. Pump Gas, NA.... turbo 8.47 @ 164.
00 ZX-12R 8.62 @ 165.2 no bars, slicks, Pump Gas, 55 shot.... turbo 8.32 @173
00 ZX-12R Fastest NA Kawasaki in the world 1: 222.046 1.5: 226.390 Loring AFB
00 ZX-12R street turbo 1: 227.9 1.5: 234.1 Loring AFB
00 ZX-12R LSR turbo 1: 263.1 1.5: 266.5 Loring AFB Worlds fastest ZX-12R
CMG Racing RCC Turbos
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Y2KZX12R
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CompetitionCNC.com
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posted May 04, 2010 01:44 AM
Scott, I kinda knew you were talking .005" not .0005" Used valves are never .0001" or .0002"
That would be a sweet deal if they sponsor you!!
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Y2KZX12R
CompetitionCNC.com
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whitehendrix
Zone Head
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Posts: 757
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posted May 04, 2010 05:25 PM
+1 on the V blocks. i have a really badass set made from 6061. set those up, set up my .0001" test indicator and give em a spinaroo at various spots alongt he stem.
____________
Duct tape is the handyman's secret
weapon. The black is for formal
occasions. - ZRXDean
ill never own a busa unless
someone gives me one.... and then
ill sell it -KZScott
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Y2KZX12R
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posted May 05, 2010 04:03 AM
quote:
+1 on the V blocks. i have a really badass set made from 6061. set those up, set up my .0001" test indicator and give em a spinaroo at various spots alongt he stem.
You are running the dial indicator on the 45 valve face right?
you dont need to run the dial indicator on the stem. If the stem is bent it will show up measuring the 45 face.
I may not have been clear on that. Sorry.
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Y2KZX12R
CompetitionCNC.com
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KZScott
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posted May 05, 2010 05:13 PM
quote:
You are running the dial indicator on the 45 valve face right?
you dont need to run the dial indicator on the stem. If the stem is bent it will show up measuring the 45 face.
I may not have been clear on that. Sorry.
I was putting it right where it contacts the seat
still trying to get this deal sorted out, so lets do the mild version Jim, sent you an email
thanks
____________
01 ZX-12R 8.84 @ 156.3 no bars, DOT tires. Pump Gas, NA.... turbo 8.47 @ 164.
00 ZX-12R 8.62 @ 165.2 no bars, slicks, Pump Gas, 55 shot.... turbo 8.32 @173
00 ZX-12R Fastest NA Kawasaki in the world 1: 222.046 1.5: 226.390 Loring AFB
00 ZX-12R street turbo 1: 227.9 1.5: 234.1 Loring AFB
00 ZX-12R LSR turbo 1: 263.1 1.5: 266.5 Loring AFB Worlds fastest ZX-12R
CMG Racing RCC Turbos
|
whitehendrix
Zone Head
fails!
Posts: 757
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posted May 05, 2010 07:28 PM
quote:
quote:
+1 on the V blocks. i have a really badass set made from 6061. set those up, set up my .0001" test indicator and give em a spinaroo at various spots alongt he stem.
You are running the dial indicator on the 45 valve face right?
you dont need to run the dial indicator on the stem. If the stem is bent it will show up measuring the 45 face.
I may not have been clear on that. Sorry.
yes sir.. if it's not blatently obvious to me, i will go on the front and back faces of the valve at the seat and .250 in from the outside edge to gauge how bad it is.. i do stem runout as well along the length.. not necessary, but i do it anyway to kinda map out how bad it is.. lets me determine if i need to address guides or the head or anything else, or at least inspect more closely than just a quick visual.
____________
Duct tape is the handyman's secret
weapon. The black is for formal
occasions. - ZRXDean
ill never own a busa unless
someone gives me one.... and then
ill sell it -KZScott
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