TurboBike
Expert Class
Posts: 121
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posted August 31, 2009 09:33 PM
Camshaft Havoc - Engine builders welcome!
This is a question for the Pro and/or experienced engine builders.
Here are some factoids about the ZX12R build on my friend's bike. This started out as a Carpenter built 1290 that eventually put out 193hp on a DJ 150 on pump gas. Carpenter uses fairly big grinds in his builds and times them at 110int 112exh to get those big HP #'s at high rpms. Specs to something like 385int and 394exh or some thing like that. Anyhow, after about 14k miles my friends blows up his stock clutch basket which resulted in mild engine damage, therefore a full rebuild was in order. Before we started, the engine was split and the trans was dissassembled completely and every part was inspected. After many days of inspection, the build went forward. So we upped the compression with new JE pistons, new Falicon knife edge rods, lightened crank with no balancer, race cut built trans with billet basket and ceramic bearings in trans. All bearings were replaced in the engine of course. Kept the original cams as they showed absolutely no issues and utilized APE springs(not sure what psi) instead of the original Carpenter springs(not sure why he did that). After all this, the bike picked up 3-4mph in the qtr right off the bat. Bike runs and revs great.
Well, the bike has about 1500 street miles since the build, 1 full road race day and 5 passes down the qtr. We make another trek to the strip to lower some ETs with more gear and some mild enhancements. We didn't even get out of first before the bike suddenly lost power. Got back into the pits and the bike sounded like it was missing a cylinder. After getting it to the shop, immediately checked for heat from the header and the #1 cylinder is cold. Checked cold compression and the other 3 cylinders showed 180psi where #1 had 25psi. Uh oh!!
Pulled the valve cover and upon quick inspection........found this........hmmmmmm......How often do you see this happen?
Intake cam
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RACE WHAT YOU BRUNG AND HOPE YOU BRUNG ENUFF
!!!!
  
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EastBayDave
Needs a job
Posts: 2245
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posted September 01, 2009 11:32 AM
wow, not an expert but kinda rare me thinks...
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Enjoy the ride!
02' ZRX1200
00' ZX12R sold
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BrooklynNYZX12
Zone Head
Posts: 520
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posted September 03, 2009 04:18 AM
 Edited By: BrooklynNYZX12 on 3 Sep 2009 12:19
I remember years ago when I was a teenager,A friends father had a 750 Honda w/a Yoshimura 810cc kit w/ Yosh cams ,it was a fast bike but it used to break cams too....Maybe the experts can weigh in,or post it in the Dragbike Zone...What was the seat and open pressures on those APE springs? I am guessing coil bind?
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Orient Express Top Street Bike Winner 8-4-07
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thekaz
Needs a job
spell chequer is bustimicated
Posts: 2909
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posted September 03, 2009 08:02 AM
I have never seen that in bikes but in big diesels it happens becuase the valve guide to valve stem tolerance is incorrect then when the diesel heats up the valve stem begins to bind on the stem....
BUT with this ???
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whitehendrix
Zone Head
fails!
Posts: 757
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posted September 07, 2009 07:01 PM
that fuggin sucks.
metal fatigue and some oddball occurance such as coil bind maybe?
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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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BrooklynNYZX12
Zone Head
Posts: 520
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posted September 08, 2009 04:15 PM
Post this in the Dragbike Zone....the guys there can help. Maybe Karl (ENTROPY)can shed some insight,he has broken just about everything in a 12 engine and then figured out why it broke...ask him
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Orient Express Top Street Bike Winner 8-4-07
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KZScott
Needs a life
high on speed
Posts: 7235
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posted September 09, 2009 01:30 PM
it was, and a bunch of guys did
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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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BrooklynNYZX12
Zone Head
Posts: 520
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posted September 10, 2009 07:24 AM
totally missed that..thanks for the slap Scott
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Orient Express Top Street Bike Winner 8-4-07
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KZScott
Needs a life
high on speed
Posts: 7235
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posted September 10, 2009 11:23 AM
Edited By: KZScott on 10 Sep 2009 19:25
any time 
I believe the general concensus was improperly torqued cam cap bolts
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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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