Shane661
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posted February 02, 2010 05:49 PM
 Edited By: Shane661 on 3 Feb 2010 01:56
Ok, there we go...
quote:
The build using Jim’s lovely head ran into trouble. No fault of the head, once the problem was corrected the engine ran fine and is producing impressive numbers. I have yet to fully scuff the motor in so details will follow.
Bottom line. Do not use JE 2mm over size pistons in a ZX14 with Jim’s stage 2 head. You will encounter interference issues with the intake valves and piston valve pockets. JE was made aware of the problem and declined to admit any design flaw or consider changing the design to accommodate larger valves. Make of this what you will.
Engine opened after incident:
A) The pistons are facing the correct way.
B) Head installed on block with Cometic 86mm gasket
C) APE studs, torque head @ 60FT/LBS
D) Confirm valve clearance 0.006 to 0.008 intake. 0.008 to 0.010 EX all OK
E) Install web cams provided. Degree cams at 0.040” checking lift. Intake opens at 16deg BTDC, closes at 46deg ATDC. Exhaust opens 49deg BBDC and closes at 15 ATDC.
F) Bike started and rattled a little. I thought I had the manual tensioner a tad loose. Tightened it and noise simply stopped.
G) Two heat cycles later; on to the Dyne and the bike was run to 3,4,5 thousand RPM at no more than 5% throttle.
H) The bike stalled for some strange reason. Tried to restart. Big pop thru the intake. At which time I decided to take a look inside.
The combustion chamber is full of shavings from the intake valves touching the back side of the valve relief in the piston. It also looks to be at a slight angle.
The valve pocket diameter measures 34.50mm across and the valves are 34.40mm in diameter so there is very little room for error.
In my opinion.
A) Either the pocket is at the incorrect angle.
B) The pocket is too close to the center of the piston.
I think it is (A) because the damage looks to be shaved at an angle.
Pistons after modification:
JE makes good pistons. In my opinion they should have stepped up to the plate on this issue but refused.
  
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KZScott
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posted February 02, 2010 05:55 PM
Edited By: KZScott on 3 Feb 2010 01:57
....
ouch
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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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rtbain
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posted February 02, 2010 05:58 PM
Shane, thanks for the help, you caught me mid-edit.
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Randy
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Shane661
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posted February 02, 2010 06:01 PM
That looks pretty ugly, glad it wasn't worse!
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wrongway
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posted February 02, 2010 06:29 PM
Not sure why you think JE is at fault here.
Needing to cut pistons on a race engine is common procedure for off the shelf pistons. It doesn't sound like you ordered custom pistons for your specific combination.
I have had to cut larger/deeper valve reliefs on every roller race motor I have built. Whenever you build an engine with larger valves , bigger cams , thinner head gaskets, or anything else that affects piston to valve clearance , the builder needs to check piston-valve clearance , including radial clearance before final assmbly.
Roy
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rtbain
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posted February 03, 2010 03:09 AM
Edited By: rtbain on 3 Feb 2010 11:17
I do see you point. JE pistons for other applications such as the Busa,ZX12, GSXR1000 and ZX10 all accomodate 1mm oversize valves. I also agree it is up to the builder to check clearancesbefore final assembly.
If nothing else my experience should serve as confirmation to this practice and a warning to others that not all JE pistons are compatible with over size valves.
My appologies to JE.
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Randy
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Shane661
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posted February 03, 2010 06:57 AM
Randle I sent you an email.
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osti33
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posted February 03, 2010 12:10 PM
Glad that the damage wasn't too bad. I agree with wrongway. Having to cut pistons is a pretty standard operation. Especially on off the shelf pistons.
Glad you got it sorted out and put back together. 
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WRECKSHOP
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posted February 03, 2010 12:22 PM
Now lets see ow much power this thing is gonna make after breaking it in ????
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rtbain
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posted February 03, 2010 03:52 PM
Working on it. Boss lady has had me busy doing silly things. Weather has kept me from putting a few miles on it before hitting the dyno.
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Randy
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Y2KZX12R
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posted February 03, 2010 05:36 PM
I was shocked that the off the shelf zx14 +2mm JE pistons had a problem with valve to pocket clearance. We've done many many +1mm O/S valve heads for Busas, zx12's gsxr1k's, zx10's, zrx's etc. and have never run into this issue. Oversize valves and offset bore blocks are another story they need a custom piston or fly cutting the valve reliefs.
With that said, Its advisable to always clay your pistons on every build.
Its interesting that the valve hit in the deep part of the pocket sidewall furthest from the pin. You can see this in the pictures. This tells me that the pocket location may be to close to the center of the bore. If I could see a clayed piston I'd be able to see the exact problem.
I talked with JE about this problem this week. They said it needs a custom piston. Funny how the other bikes mentioned don't need a custom piston for an over-sized valve.
Damn, I wish Noonan still worked there. He would have listened and actually checked into this issue. For all we know at this point this set of pistons could have just been made wrong.???
I'll be talking to them at the Indy Dealer Show in a few weeks to try and resolve this valve pocket issue. I'd like to see a modification to the off the shelf piston so the pistons aren't as expensive.
But if I have to I'll just spec out a proper custom piston for the zx 14 and stock it.
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Y2KZX12R
CompetitionCNC.com
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wrongway
Pro
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posted February 03, 2010 06:34 PM
quote:
Damn, I wish Noonan still worked there. He would have listened and actually checked into this issue. For all we know at this point this set of pistons could have just been made wrong.???
......
But if I have to I'll just spec out a proper custom piston for the zx 14 and stock it.
[/quote
Looks like John Noonan is working for Wossner now, and they are selling busa pistons and rods. maybe a better source for custom stuff.
http://www.hayabusa.org/forum/turbo/120088-wossner-turbo-pistons-h-beam-rods.html
Roy
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smokinZX14
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posted February 03, 2010 07:12 PM
Still can't take picture of the head ? Oh i forgot it's top secret ....
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Smokin Performance Cycles..
Tampa Bay , FL .. Brocks Performance Dealer ..
Gen 2 ZX14R Best ET 8.43 , Best MPH 164.95
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Y2KZX12R
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posted February 03, 2010 07:41 PM
Wrongway, I was wondering where he wound up. Thanks.
Smokin, I should have taken some pics before I shipped it. The next one I will.
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Y2KZX12R
CompetitionCNC.com
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wrongway
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posted February 04, 2010 07:12 AM
I guess the bad news is that I cannot just bolt on a stage 2 head without tearing the motor down and taking the pistons out. The stroker kit also uses JE pistons , and I bet the valve pocket location and dimensions are the same .
Looks like just some minor porting on a stock head this season.
Roy
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SteddyTeddy
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posted February 04, 2010 08:36 AM
Custom pistons. LOL All they need to do is make a couple changes to their CNC program
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Y2KZX12R
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posted February 04, 2010 08:41 AM
The good news is that the custom piston wont be that much more than an off the shelf piston.
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Y2KZX12R
CompetitionCNC.com
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WRECKSHOP
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posted February 04, 2010 10:27 AM
Should have went with CP pistons. They are a lot better design and quality than JE pistons. And I have received very good reliable information that Wossner is developing pistons and rods for the ZX-14 and should be available within the next few months !!!!
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Y2KZX12R
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posted February 05, 2010 05:14 AM
I've heard good things about wossner pistons. I'll be resizing 2 sets of wossner H beam rods for Brian at Quantam Motorsports in a week or so.
I'll get some pics of them.
He has used the pistons before. 1 set was for a turbo busa and the other was a regular busa piston. He was impressed with them.
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Y2KZX12R
CompetitionCNC.com
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WRECKSHOP
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posted February 07, 2010 11:06 AM
Cool...
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ZX14Mike
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posted February 07, 2010 11:21 PM
I think Wossner pistons are stock in KTM............I've heard good things about them as well.........heard they last a LONG time compared to what the Big 4 use.
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SteddyTeddy
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posted February 08, 2010 06:07 AM
quote:
I was shocked that the off the shelf zx14 +2mm JE pistons had a problem with valve to pocket clearance. We've done many many +1mm O/S valve heads for Busas, zx12's gsxr1k's, zx10's, zrx's etc. and have never run into this issue. Oversize valves and offset bore blocks are another story they need a custom piston or fly cutting the valve reliefs.
Scatch the ZRX off that list. My +2mm JE pistons needed cut for the +1mm O/S valves, just on the exhaust side. Looked at though JE had the center lines off slightly.
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Shane661
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posted February 08, 2010 07:26 AM
JE's rep seems to be taking a beating lately. They also had some recent issues with Busa turbo pistons cracking.
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NINJA12
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posted February 08, 2010 11:07 AM
I remember when 99% of the A/M pistons were JE or Wisco, now we have MTC, Wossner, and CP
all of which seem to have a better rep for quality that the first 2.
As the price difference is getting smaller, fewer people wil gamble on quality.
If they don't learn about quality and customer service they would survive much longer.
Professional builder know what to look for to make the most of the cheaper parts and their profits, but most use custom parts. NOT off the shelf.
This may not be the best part for the average builder trying to save a few dollars by building their own engines.
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dubious
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posted February 10, 2010 02:41 PM
Thought i would add, that my stock bore turbo 9.5 pistons would not clear oversize intake valves either.
I do not fault JE for that unless a oversize pocket is specified.
The zx14 intake valves run right to the edge of the cylinder at the outermost part from what I recal.
I didn't check but is there even room with the stock valve angle to go oversize on a stock bore without notching the cylinder for clearance?
____________
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destiny will overcome intervention.
Some are not worthy of the effort.
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