KZScott
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posted December 23, 2008 01:26 PM
strange piston pin "wear"?
upon further tear down of my motor (1287) for inspection/cleaning I noticed a few things
one, my rings arent as worn as i expected. the second ring is only contacting the cylinder wall for about half of its thickness. is this normal or did i switch to synthetic oil way too soon and not get a full break in?
two, more importantly, my piston pins are rough (feel it with a fingernail) in the middle where they are inside the rod. 1 and 4 pulled out nicely, while 2 and 3 were a bit sticky but still pushed out. #3 is the worst as is the corresponding piston. What caused this? blocked oil passage? wrong size? new JE pistons and pins last winter.
pics
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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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tcchin
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posted December 23, 2008 01:58 PM
How did the rod small end look? Was the circlip difficult to remove?
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KZScott
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posted December 23, 2008 02:07 PM
circlips came out just like normal. the rod small end is slightly rough. #3 being the worst. very similar "wear pattern" as the pins
____________
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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flite leader
Zone Head
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posted December 23, 2008 02:22 PM
small end problems dont happen in isolation
what do your big end rods & bearings look like
be certain not to mix em
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Y2KZX12R
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posted December 23, 2008 02:39 PM
Scott,
The second ring is actually an oil ring. There are several types out there these days but they all try and do the same thing, scrape oil off the cylinder wall.
As long as the shiney part of the face of the ring was facing down or on the lower half of the face then you had them right.
Pin galling is typically seen when the piston is hitting the head. Look at your pistons and head very carefully and see if you can detect any contact. It may not be in the squish area either. It could be in the chamber.
You can hone the pin bores slightly to clean them up. the pins as well. Check the rod small ends also.
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flite leader
Zone Head
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posted December 23, 2008 02:48 PM
scope the pix of the valves hitting the head
already considered that
but lookin at the big end will tell the story
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tcchin
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posted December 23, 2008 03:04 PM
Jim - With head contact, won't the galling typically be worse on the lower surfaces of the bearings than on the upper, due to the load vector? Some material will get dragged around to the upper surfaces, but most of the damage and discoloration should be on the lower surfaces, right?
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KZScott
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posted December 23, 2008 03:06 PM
 Edited By: KZScott on 23 Dec 2008 23:15
thanks Jim, learn something new every day  I thought the whole surface of the ring was supposed to touch. the shiny part was on the bottom, which makes sence if its job is to scrape oil downwards. going up it has a taper and wouldnt catch as much of the oil.
the pistons were tagging the head. one of the reasons i want to shoot for slightly more squish this yr.I want to be closer to .040 (it was a bit tighter)
rod small ends are slightly rough. (pics didnt focus well) they have the same "wear" pattern as the pins.
VERY glad my pistons arent "shop decorations". is a machine shop required to fix these issues or can i do this myself? 1500 grit sand paper?
thx!
____________
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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posted December 23, 2008 03:17 PM
quote:
Jim - With head contact, won't the galling typically be worse on the lower surfaces of the bearings than on the upper, due to the load vector? Some material will get dragged around to the upper surfaces, but most of the damage and discoloration should be on the lower surfaces, right?
hmmm the only damage looks to be at the top of the pin bore. the bottom of the pin bore is fine. "shrugs"?
dont have the cases split to see the rod bearings yet, but im guessing some damage
____________
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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dougmeyer
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posted December 23, 2008 03:55 PM
Y2 has it exactly right ( ot course). I wouldn't expect that what you have is bad enough to mess the big ends.
Hone the small ends and pin bores to clean them up, give yourself .001" clearance minimum. What's with the nasty ass valve tag. That certainly didn't help.
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Y2KZX12R
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posted December 23, 2008 05:10 PM
Edited By: Y2KZX12R on 24 Dec 2008 01:31
quote:
Jim - With head contact, won't the galling typically be worse on the lower surfaces of the bearings than on the upper, due to the load vector? Some material will get dragged around to the upper surfaces, but most of the damage and discoloration should be on the lower surfaces, right?
Well, the metal to metal will happen when the oil is squeezed out mechanically at TDC when the piston actually is hitting the head. If its severe enough (this doesnt seem to be) you can see some damage to the rod bearings, but by that time the pistons would be junk.
The pin is oiled by the oil collection in the oil ring and sent thru an internal passage to the pin bore in the piston, and thru a hole in the end off the rod, if it has one.
It has to be severe for the rod journals to make contact with the rod bearings, with the rod bearings being pressure fed and all.
But yes, the bottom of the rod small end and the top of the pin bore in the piston. And if severe the top of the rod big end.
Its possable that the contact only happened when the engine wasnt fully warmed up. Factory pistons run VERY tight clearances in the bore because the pistons are designed to control expansion VERY carefully. They are a hypereutectic alloy that contain high silicon levels to reduce expansion and so they are tighter cold in the bores but harder and more brittle. (they also help reduce emisions so the feds like em)
Your pistons are forged hypoeutectic so they contain less silicon to make them more forgivable in extreme applications and they also expand and grow a lot more when hot.
So you guys running any hypoeutectic (most aftermarket forged) pistons be carefull of reving or loading the engine untill its FULLY warmed up. You can break or partially collapse a skirt. The pistons can also hit the head during this time but may not once the engine is warmed up fully.
You can actually hear the pistons "slapping" around untill the engine is warmed up. That is if your pipe wasnt so loud.
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Y2KZX12R
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posted December 23, 2008 05:37 PM
quote:
...is a machine shop required to fix these issues or can i do this myself? 1500 grit sand paper?
Its best to hone them on a rod resizing machine. But if its not to bad you can clean them up a little with some 1500 paper on your finger. Polish the pins and rod small end the same way with 1500.
A local machine shop should be able to hone them in just a few min for you. It takes very little honing to clean them up. If you cant find anyone to do it local and dont want to do it by hand, we can hone them for you.
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KZScott
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posted December 23, 2008 06:31 PM
quote:
Y2 has it exactly right ( ot course). I wouldn't expect that what you have is bad enough to mess the big ends.
Hone the small ends and pin bores to clean them up, give yourself .001" clearance minimum. What's with the nasty ass valve tag. That certainly didn't help.
definately didnt help! check out this thread Doug, page 2 is where it gets into the motor, just ignore the back and forth bs with flite(hes on my ignore list now)
http://www.bikeland.org/board/viewthread.php?FID=13&TID=43105&pagenumber=2
thx for your input, its allways welcome
____________
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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posted December 23, 2008 06:46 PM
Jim, once again thank you for the info Ill see what happens by hand first and go from there. I like doing as much as possible myself (which is actually great for my budget  ). I really enjoy working on this stuff and learing as much as i can. trust me, If its in the budget as much of my stuff as possible will be going to you for work. head, rods ect
somehow i dont think i could hear piston slap over a muzzy pipe is going by oil temp the proper way to assure a warmed up and "ready to be thrashed on" motor? or should it reach a certain temp for X amount of time?
____________
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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whitehendrix
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posted December 23, 2008 11:23 PM
hmm.. so what would be the root cause of the galling.. has it een determined yet?
does look alot like oil starvation, but i would surmise that if it was an extreme case, you would have never gotten the pins out in the first place.
or maybe you caught it early?
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Y2KZX12R
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posted December 24, 2008 02:55 AM
Scott, Without an oil temp gauge I'd say 10 min of riding after the water temp is at its "normal" place should be fine.
quote:
hmm.. so what would be the root cause of the galling.. has it been determined yet?
See my above post, its from the piston hitting the head.
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VincentHill
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posted December 24, 2008 08:38 AM
Edited By: VincentHill on 24 Dec 2008 16:40
Scott, I have used Crocus Cloth to clean up the Piston Pins and Small end of the rods using a small Wheel cylinder Hone wrapped with the Crocus cloth provided there is no metal build up on the Rods!
When everything is heated up the Piston Pins float and the taperd end gets trapped at the end by the circle Circlip! Before this was full understood, Wiseco used Spiral Locks with would come out and also Piston Buttons that rubbed against the sides of the Cylinder and could wear out. Also at one time before this was all fully understood the circlips had tangs to help remove them which would break and later be found embedded into the Piston somewhere!
1500 W&D paper is good but I think Crocus Cloth is better. (No disrespect to Jim or Dr. Doug
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2000redrocket
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posted December 24, 2008 11:20 AM
so jim or doug what is the min clearence of piston to head for assembly? i think a guy from a long time ago in jersey (dan from action machine who owes me 400 bucks yet) said vlvs are .060 which i think is close. but he is the one that had me put 1500mi on the engine then go .004 to .006 valve clearence from the loose initial clearence like .011 to .013 on my zx11. it picked up .15 in the 1/4 with the tighter valves. cars with aluminum rods are like .060 so maybe even closer???
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APE Jay
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posted December 24, 2008 03:28 PM
We have tool steel pins for those pistons. JE pin bores are slightly undersize, so you can givew them a couple of strokes on the pin hone and install the good pins and you are ready to go.
If you don't have anyone to do that, send them to us and we will turn them around same day.
Jay
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dougmeyer
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posted December 24, 2008 05:11 PM
P to H - Well it depends on a few things, how large a bore, piston to wall clearance, what you're doing with the engine. Think about the geometry, the larger the bore, the greater the distance the the top edge of the piston can move when it rolls around the pin axis (called "rock"), also the greater the bore clearance and the shorter the skirts the more the piston CAN rock.
If you are building a drag engine or road racer where over rev's are likely, you need to give yourself some extra room.
On my Bonneville engines, where I have the time to shift very carefully and compression rules, I run them very close.
My indication that I have it just right is when there is no carbon on the squish area, but no actual contact either, well, maybe just a little..... Any real contact will show on the dyno as mysteriously lost hp.
On my 11 and 12 engines that's about .035"-.037". If I was building something with margin for error I'd run .040-.045".
Jim?
Hi Jay!!
Doug
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Y2KZX12R
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posted December 25, 2008 05:14 AM
quote:
P to H - Well it depends on a few things, how large a bore, piston to wall clearance, what you're doing with the engine. Think about the geometry, the larger the bore, the greater the distance the the top edge of the piston can move when it rolls around the pin axis (called "rock"), also the greater the bore clearance and the shorter the skirts the more the piston CAN rock.
If you are building a drag engine or road racer where over rev's are likely, you need to give yourself some extra room.
On my Bonneville engines, where I have the time to shift very carefully and compression rules, I run them very close.
My indication that I have it just right is when there is no carbon on the squish area, but no actual contact either, well, maybe just a little..... Any real contact will show on the dyno as mysteriously lost hp.
On my 11 and 12 engines that's about .035"-.037". If I was building something with margin for error I'd run .040-.045".
Jim?
Hi Jay!!
Doug
Yea, agreed Doug.
When you set an engine on "kill" you have little or no room for error. Miss a shift and you can damage the engine. Thats where you have to balance reliability with power. If you cant finish the race or go all the rounds to the end, then none of it matters.
Thats the difference between the qualifying engine and the "feature" engine.
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KZScott
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posted December 26, 2008 02:25 PM
quote:
Scott, Without an oil temp gauge I'd say 10 min of riding after the water temp is at its "normal" place should be fine.
and if i put on an oil temp gauge?
Jay, why arent the JE pins "good pins" ? they were in the piston kit that i got from APE
2 yrs in a row now i wasnt able to finish the local heads up event. (first time was trans popping in and out of gear, this time spit shims) you better believe i want this build to last a full season! safer numbers will be used this go around
____________
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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entropy
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posted December 26, 2008 03:30 PM
KZ,
I believe you had a solid build last time. Opening up the squish by .005" might be a lil bit safer?
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KZScott
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posted December 26, 2008 08:59 PM
definately, i do miss shifts every now and then(usually the 2-3 on a nitrous pass last yr(spray was activated in 2nd) . Im having the rods resized to bring them back to round and the tight end of the spec. that should open it up some, but i wont know how much untill i put it together. in your expirience, how much has resizing the rods affected squish?
____________
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
|
flite leader
Zone Head
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posted December 27, 2008 09:09 AM
quote:
thanks Jim, learn something new every day I thought the whole surface of the ring was supposed to touch. the shiny part was on the bottom, which makes sence if its job is to scrape oil downwards. going up it has a taper and wouldnt catch as much of the oil.
the pistons were tagging the head. one of the reasons i want to shoot for slightly more squish this yr.I want to be closer to .040 (it was a bit tighter)
rod small ends are slightly rough. (pics didnt focus well) they have the same "wear" pattern as the pins.
VERY glad my pistons arent "shop decorations". is a machine shop required to fix these issues or can i do this myself? 1500 grit sand paper?
thx!
those pistons cant be reused
no less as i mentioned b4 ............small end problems DONT happen in a vacuum
if those pistons werew smaking the head that much
you have big end bearing problems
imagine smacking the pistons with a ball peen hammer
it has a direct effect on th big end bearings
it has toooo
no less you arent gaining "Squish"............
squish has more to do with combustion chamber "SHAPe" than
valve.... piston or heaad clearances
you constantly Bust me out while making serious mistakes & ive told you
NOTHING WRONG
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bend your mind.....
or break your ass...!!
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