KZScott
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posted June 11, 2008 06:16 PM
CL's PTV ect (engine builders plz read)
on my build, what would the experts estimate my quench height and PTV to be with the following:
no block shim, head milled 5 thou, CL's 105 105 or CL's 106 107, JE 86mm 13.5:1 pistons (as far as i know the only work ever done to the valve seats was me lapping them in, used seats, used valves )
i plan on measuring, but if its going to be way off(bad) plz recommend a better setting
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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zrxdean
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posted June 11, 2008 08:04 PM
What I've seen listed is .030 squish, and .045 int .065 ex PTV clearance.
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entropy
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posted June 11, 2008 10:56 PM
quote:
What I've seen listed is .030 squish, and .045 int .065 ex PTV clearance.
looks good to me. 30 squish is getting tight, certainly doable, but measure all 4.
how are you gonna measure squish?
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johnnycheese
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posted June 12, 2008 02:55 AM
anything under .024 will detonate with pump gas
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Y2KZX12R
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posted June 12, 2008 03:49 AM
quote:
quote:
What I've seen listed is .030 squish, and .045 int .065 ex PTV clearance.
looks good to me. 30 squish is getting tight, certainly doable, but measure all 4.
how are you gonna measure squish?
I agree.
The minimum on those clearances is also a factor of who is riding the bike. If its a customer bike or a pure race bike and if it will get proper warmup time EVERY time it fires up. If the oil isnt 160-170 degrees for several minutes then the engine isnt warmed up.
Water temp means nothing.!!
Also will the engine be shutoff and restarted hot with the factory starter etc. As in a street bike. Have you ever wondered why a race engine can be hard to restart if it stalls.?
.035" squish and .045"/.055" are good solid safe numbers with forged pistons.
Factory pistons, you can get down to I .030"/E.040" on the PTV and .025" on squish in an all out setup depending on the pistons used.
Like Karl says, you need to check every valve and every piston when you get down to the low end of these clearances. The rods are not the same length, the pistons have slightly different pin heights and slightly different skirt clearances also different valve pocket depths. The valve seats are slightly different depths.
I'd stay with the safer numbers for all but the most all out builds.
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NOX
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posted June 12, 2008 05:05 AM
quote:
anything under .024 will detonate with pump gas
What is this "pump gas"...........??
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tcchin
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posted June 12, 2008 01:22 PM
quote:
on my build, what would the experts estimate my quench height and PTV to be with the following:
I don't think there's any way to estimate what your numbers are, and I don't think it's safe to assume anything. Measure everything twice and shoot for the numbers recommended in the thread so far. Note that it's far cheaper to be conservative.
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KZScott
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posted June 12, 2008 01:38 PM
 Edited By: KZScott on 12 Jun 2008 14:40
thx guys, so go by those numbers or bigger 
Karl, i was going to use your crushed solder method. i read about that in one of your old threads on checking quench height. i believe VH used a similar method to check PTV... i wish i had of bookmarked those threads...
i do plan on running pump gas as much as possible, unless i need higher octane for "some" nitrous.
it is a street bike, not just a drag bike, but its getting to be close to the edge of just a drag bike 
____________
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
Zone Head
Posts: 867
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posted June 12, 2008 09:15 PM
I don't think I'd use solder to measure PTV. Too much risk of damage to the valves and too much tearing stuff apart. If only there were a tool to do that...
Using solder to measure squish is fine, just be sure to do all four quadrants on all four pistons, and use a little thick grease to hold the solder in place on the pistons.
As for lobe centers, I'd start out as narrow as you can get while still maintaining your PTV. See where your torque peak is on a dyno and adjust accordingly. Maximum area under the torque curve is nominally the goal. There's a lot of stuff written about lobe centers, and everyone has their own opinion. I try to base mine on lap times first, dyno charts next and internet opinions last. YMMV.
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entropy
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posted June 13, 2008 04:36 AM
as TCC says solder works great for quench but the thought of using it for PTV makes me cringe (after spending so much on those seats/valves)
best to use solder pieces all cut to the the same length, i do1/4"
after u grease em in place, rotate & crush em, average the measured thicknesses of F-B, L-R pair for ea cly. They will crush a lil differently sometimes
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KZScott
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posted June 14, 2008 06:49 AM
ok i should be fine measuring quench.
is .030 ok for forged pistons? Jim, didnt you run .031 in your 1375? or was just that the stock setting with no block shim? another question, will my quench change by just swapping pistons?
i dont have Tims fancy PTV tool, so some sort of clay or(???) to put in the valve pockets?
another question. which cam timing combo is safer as far as PTV is concerned? 105 105 or 106 107 (the 2 options i was recommended)
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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tcchin
Zone Head
Posts: 867
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posted June 14, 2008 08:48 AM
Not knowing which rods you have, I'd have to say that .030" would be about as tight as you want to go. Your squish *may* change when you change pistons, so you *need* to check it. I have had custom pistons made with non-stock deck heights to adjust squish, and there's always manufacturing tolerances to take into consideration.
You can always use a light replacement valve spring from the hardware store and depress the tappet with a dulled screwdriver. The problem with the clay method is that you only get one measurement per assembly/teardown sequence. If you're chasing some valve clearance numbers and it takes you five or six tries to make your numbers, that's five or six teardowns that you need to endure.
PTV will decrease as your lobe centers get smaller (advance the intake or retard the exhaust). Unfortunately, some good performance can be found in those areas sometimes. Back in the day when Formula Xtreme was fun, we were allowed to bore/stroke literbikes, use Ti valves, wild cams, etc. At certain tracks, we would run lobe centers in the 96-99 region and still have plenty of top-end. So again, I'd set the cams as your PTV allows (probably somewhere in the 101-105 region), and then adjust the area under your torque curve on the dyno by increasing your lobe centers. The good thing about using this technique is that you only have one direction to go (larger on LC and more PTV), rather than starting in the middle, guessing which way to go and wondering if you're running close to your PTV limits. Of course, if you're happy with the shape of your torque curve, you can just leave it all alone...right Karl?
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KZScott
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posted June 14, 2008 10:25 AM
stock rods
im worried about top end even if streetability (low end) suffers a bit, so ill go with the 106 107 lobe centers and hope for the best for HP as long as it has lots of clearance(which it really should, i think the pistons have deeper valve pockets than stock). no dyno close, and good ones are really far away (got a data logger to fine tune with) so i wont be on the dyno playing with cam timing  set them once and tune the AFR for that setting. i would love to try the technique you outlined above, but i cant afford that type of thing at the moment, and im very strapped for 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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KZScott
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Posts: 7235
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posted June 14, 2008 09:12 PM
ok quench height worked out in the safe zone, i measured on 1 4
avg on 1 = 0.036150"
avg on 4 = 0.039525"
avg of that = 0.0378375"
Awesome!!!
i was expecting around 0.031___. proof to measure and not assume based on someone elses build!!! lesson learned! (finally not the hard way too )
tonight was a good night
____________
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
|
entropy
Moderator
Posts: 8671
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posted June 15, 2008 03:01 AM
.040" on #4 and .036" on #1 = looking good.
I'm a lil surprised at the .004" difference seeing as you are using stock rods and crank, but it's fine.
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entropy
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posted June 15, 2008 03:06 AM
Q: are you gonna do the "soft spring" method of PTV??
If so, do it on #1 cyl, the one with the tight Q.
also, prob not needed cause you aren't that tight, but i would be looking for Q info on 2, 3 also.
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KZScott
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posted June 15, 2008 07:42 AM
Karl, im not exactly sure... i was thinking an EX spring but only either the outside piece or inside piece. I have a rough idea of how to do this, but if you could break it down for me and tell me how you would do it, i would really appreciate it!
____________
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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