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Z2 750 crank (Bossie the Kaw)
- SWest
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- 10 22 2014
Steve
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- Tyrell Corp
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But remember CR and compression pressure is not exactly the same thing, the wilder GPz variants often have lower compression pressures despite higher CR due to the hotter cams.
What are the chances of that being a pre z1 750 crank?
Assuming the extra squish doesn't cause problems, you have a great candidate for a turbo bike with the modest CR and mild cams. And with all that clearance you can rag the nuts off it without piton/valve interference.
Don't close the thread, I think it is interesting. These jobs always take a long time of planning and accumulating parts beforehand, so nice to see it coming together and up and running with a few days.
1980 Gpz550 D1, 1981 GPz550 D1. 1982 GPz750R1. 1983 z1000R R2. all four aces
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- SWest
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Maybe I should put the 60's back in and raise the needles?
It came out of a wrecked Z2 750 engine. I don't plan on putting a Turbo on it, I don't want to be launched off a cliff. :lol:
I'm thinking on sending this thread to the original Poser thread. Lots of info there and combining the two just makes sense to me.
Comments?
Steve
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Tyrell Corp wrote: A comp test at 500 and at thousand miles will tell you the real numbers. Mines at 165 last check so thinking its right at 10/1 or a hair under.
But remember CR and compression pressure is not exactly the same thing, the wilder GPz variants often have lower compression pressures despite higher CR due to the hotter cams.
What are the chances of that being a pre z1 750 crank?
Assuming the extra squish doesn't cause problems, you have a great candidate for a turbo bike with the modest CR and mild cams. And with all that clearance you can rag the nuts off it without piton/valve interference.
Don't close the thread, I think it is interesting. These jobs always take a long time of planning and accumulating parts beforehand, so nice to see it coming together and up and running with a few days.
Thanks Tyrell so your saying since I put in the slightly warmer 750 cams I am a "little" bit better off yet ? Maybe I'll get to that 101/4 to one after all. Only went with a min cut on the head APE said .004 got it and it looked perfect. Moving this to the original Poser thread sounds good to me.......I'm interested in following your build Steve.
1978 KZ650 b-2
700cc Wiseco kit 10 to 1.
1980 KZ750 cam, ape springs, stock clutch/ Barnett springs.
Vance and Hines Header w/ comp baffle and Ape pods, Dyna S and green coils, copper wires.
29MM smooth bores W/ 17.5 pilots, 0-6s and 117.5 main
16/42 gearing X ring chain and alum rear JT sprocket.
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More duration and overlap onthe cams increases power and brings it up on the rpm range...think grunty z650 compared to screaming redline zx750 unitrack. A very nice compromise might be GPz750R1 cams, if you can find.
What i like about this thread is it is 'wrong' , just like my earlier'wrong' low compression GPz 550 build that worked really nice -until I trashed a piston 5k miles later. All the muppets laughing at Steve as he has a part he hasn't correctly identified - join the club, this is what happens when you hoard 30 year old motorcycle parts.
1980 Gpz550 D1, 1981 GPz550 D1. 1982 GPz750R1. 1983 z1000R R2. all four aces
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- SWest
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Steve
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- missionkz
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Bruce
1977 KZ1000A1
2016 Triumph T120 Bonneville
Far North East Metro Denver Colorado
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- SWest
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Bruce, when you went to your 1075 kit, were your 1015 pistons even with the deck? If so did your 10.5 pistons sit above the deck?
This is one of those things that will bother me until it's solved. :pinch:
Steve
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So much so that I considered using two base gaskets but taking head gasket crush into consideration, they were still below the top of the metal ring made into the head gasket. So I let it go.
Also, keep in mind that the 8mm difference in stroke means 4mm up and 4mm down so if you have a 58mm stroke, the pistons would only be 4mm (or less then .16") below flush with the deck.
Bruce
1977 KZ1000A1
2016 Triumph T120 Bonneville
Far North East Metro Denver Colorado
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- SWest
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Steve
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- SWest
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Steve
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- SWest
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Steve
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