KZScott
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posted September 29, 2009 01:16 PM
ping y2k,(and other gurus) cam selection for stock buckets
Jim, I remember awhile back you posted the max cam lift/duration for stock zx12r buckets, i believe it was the megacycle 419-x1 ? L/D= .405 / 255
without getting into any fancy machining, or complete rebuild(stroker), im wondering how much more power i can get out of my current setup. i have .358 / 246 on both sides right now. stock IN valves, and the 1mm OS exh valves you put in. if i were to just get one new cam, where should it go(in or exh?), and how much of a gain should i expect? also curious as to how much of a gain i would get with getting 2.
trying to get ideas for the winter 
thx
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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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Y2KZX12R
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posted September 30, 2009 03:57 AM
Well Scott, Valve velocity is somewhat limited on the zx12r and zx14 due to the 26.5mm buckets.
This is the reason the cams listed by Megacycle for the zx12r are smaller than busa cams.
But in general, the zx12/14 are limited to about .4"/245 or there abouts. As duration grows lift can go higher, to a point.
If you really want the biggest cams possible for a 26.5mm bucket I can call Jim at Megacycle and see what other lobes he can recommend.
Or just put 28mm buckets in the head and be done with it. The added weight of the 28mm bucket and weight reduction on the TI retainers will still rev to 12,500 with APE springs.
With an added 1mm of lift on intake and exhaust there should be some good power gains. Mostly above 7000. But you will want at least 13 to 1 CR .
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Y2KZX12R
CompetitionCNC.com
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KZScott
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posted September 30, 2009 01:14 PM
hmmm, im guessing busa buckets, ti retainers, machining, and cams wouldnt really be cost effective in the power department unless we are talking in the range of 20 hp (doubtful). Im probly going to look for somthing thats about the max for stock buckets, if i get cams unless i can find a great deal on a used set.
I have Carpenter springs... they are stiffer than APE correct?
my motor is currently at 13:1, but the head has plenty of material that could be shaved off(only has 5 thou off total.)
i am looking for top end power, not low. track performance is top priority
im open to suggestions besides cams (yes i have nitrous lol)
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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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Y2KZX12R
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posted October 02, 2009 03:11 AM
Yea it gets more and more and more expensive to extract the last dozen or so hp from one of these engines.
A pair of cams for stock buckets is the least expensive route. Stage 2 porting is recommended with them.
I don't know what springs carpenter is using. But you don't need any more spring tension than 60# I didn't do any spin-tron testing on my setup but with .443"/.415" cams, os buckets and valves, the APE springs keep everything in control. So any cam for a stock bucket wont need more spring, It simply wont have the valve velocity to even worry about it.
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Y2KZX12R
CompetitionCNC.com
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KZScott
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Posts: 7235
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posted October 02, 2009 11:19 AM
they are supposed to be 65lbs seat pressure
so with the 2 biggest cams possible for stock buckets, im looking at around 8ish hp?
____________
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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Posts: 3762
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posted October 05, 2009 12:06 PM
quote:
they are supposed to be 65lbs seat pressure
All valve springs should be cycled to coil bind several times before putting them in the head. Once cycled the spring pressure drops a little. This is totally normal.
quote:
so with the 2 biggest cams possible for stock buckets, I'm looking at around 8ish hp?
Its hard to say Scott. I didn't even know for sure how my engine would respond to these big cams I am using until I dynoed the engine. I had an idea from running dozens of simulations in Dynomation, but you never really know until you are actually burning gasoline.
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Y2KZX12R
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Shane661
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posted October 05, 2009 12:09 PM
Jim...why do aggressive cams need larger buckets??
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Y2KZX12R
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posted October 05, 2009 07:43 PM
Because the lobe runs off of the edge of the bucket. The cams will wear out fast and the profile will be messed up.
Its a valve velocity issue. Big lift and short duration.
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Y2KZX12R
CompetitionCNC.com
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