J motor max displacement

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J motor max displacement

04 Mar 2024 14:59
#895959
What is the max displacement a stock cylinder kz1000 J motor can get to?

How about with the stock crank? Aftermarket crank but stock block?

Thank you.

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Re: J motor max displacement

04 Mar 2024 15:19
#895962
It's not a small block Chevy, where you can order up a stroker crank!  Pretty much all motor size increase comes from bigger pistons.  You might want to check Weisco.  Or, just wait.  There are guys here that can tell you every possible size on the planet, based on available pistons and max bore of the liners!  
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Re: J motor max displacement

04 Mar 2024 15:23
#895963
Here are a bunch of options. APE will go up to 1500cc with their block.

kzzone.com/pistons.html
1982 KZ1000 LTD parts donor
1981 KZ1000 LTD awaiting resurrection
2000 ZRX1100 not ridden enough

www.kzrider.com/11-projects/620336-anoth...uild-thread?start=24
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Re: J motor max displacement

04 Mar 2024 16:02
#895965
Ok.

 Thank you for the link.

Looks like 1075cc with stock sleeves.

1260cc with changing the sleeves.

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Re: J motor max displacement

04 Mar 2024 16:04 - 04 Mar 2024 16:08
#895966
Darn!

You mean I can’t get a siamese bore cylinder to get me to 3,500cc?

Edit to add, but I did see a bike with half of a Vette LS engine for it’s motor.

That would be pretty sick. I don’t know what they did for the transmission though? I jokingly want to say Baker 6speed from the agricultural world.
Last edit: 04 Mar 2024 16:08 by RedPill.

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Re: J motor max displacement

04 Mar 2024 20:25 - 04 Mar 2024 20:27
#895973
DIY KZ 1600. Not a J engine, though.

www.rideapart.com/news/463729/allen-mill...awasaki-z1-v8-build/

Just in case you are in need of the utterly insane Kawasaki-

www.throttlextreme.com/48-cylinder-kawas...e-insane-motorcycle/
 
1982 KZ1000 LTD parts donor
1981 KZ1000 LTD awaiting resurrection
2000 ZRX1100 not ridden enough

www.kzrider.com/11-projects/620336-anoth...uild-thread?start=24
Last edit: 04 Mar 2024 20:27 by TexasKZ.

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Re: J motor max displacement

04 Mar 2024 21:05
#895974
That V8 Z1 is way cool.

48 cylinders? I wonder how many gallons of gas just to sync the carbs?

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Re: J motor max displacement

05 Mar 2024 06:36 - 05 Mar 2024 06:38
#895984
Ok.

 Thank you for the link.

Looks like 1075cc with stock sleeves.

1260cc with changing the sleeves.

 
I am in the process of building a hot street 1197cc engine, the liners are now .100" thick so I would not advise anybody to build a 1260 for street use.

A 1075 engine is plenty strong and a lot cheaper option, if I did not get my pistons for free I would have went 1075 cc. Building a big CC Z engine from scratch is getting more expensive than in the past expect anywhere from $3-5K to do it proper.

 
1978 KZ650B2 w 1197cc Z1 engine
1977 KZ650B1 w 750cc Spectre engine
1979 KZ650C3 w 831cc Hot Rod engine
1978 KZ650C2 w 762cc DFI project
1977 KZ650C1 stock restoration project
1978 KZ650B2 modified project
1978 KZ650B2 Injected Drag 831cc
1980 Z1 Custom Frame Drag 1327cc
1981 Z50R Honda tow bike
Last edit: 05 Mar 2024 06:38 by Injected. Reason: info

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Re: J motor max displacement

05 Mar 2024 07:53
#895989
Ok.

 Thank you for the link.

Looks like 1075cc with stock sleeves.

1260cc with changing the sleeves.


 
I am in the process of building a hot street 1197cc engine, the liners are now .100" thick so I would not advise anybody to build a 1260 for street use.

A 1075 engine is plenty strong and a lot cheaper option, if I did not get my pistons for free I would have went 1075 cc. Building a big CC Z engine from scratch is getting more expensive than in the past expect anywhere from $3-5K to do it proper.


 

At what point is a crank rebuild/welding job needed?  I'm guessing that's pushing $1000 these days?

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Re: J motor max displacement

05 Mar 2024 08:26
#895990
Crank starts at about $1250 from Gardner then goes up depending on what you need

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Re: J motor max displacement

05 Mar 2024 08:57 - 05 Mar 2024 11:24
#895992
Ok.

 Thank you for the link.

Looks like 1075cc with stock sleeves.

1260cc with changing the sleeves.






 
I am in the process of building a hot street 1197cc engine, the liners are now .100" thick so I would not advise anybody to build a 1260 for street use.

A 1075 engine is plenty strong and a lot cheaper option, if I did not get my pistons for free I would have went 1075 cc. Building a big CC Z engine from scratch is getting more expensive than in the past expect anywhere from $3-5K to do it proper.






 

At what point is a crank rebuild/welding job needed?  I'm guessing that's pushing $1000 these days?



 
The old racers reply would be if you intended to run a slick or not. Slick bikes always require a welded crank.

Yes, "real" rebuilt and welded cranks start at $1000 from APE (web site) maybe a bit cheaper at Pearson, not sure who else does them.

For this street bike I had mine done by the same guy that does my boring and cylinder heads. He charged me $200 to inspect/weld/true, the welds are not all the way around the pins. For the kind of HP a street bike makes you really don't need a complete rebuild job, just weld the pin edge that you can get to. This is assuming low mileage virgin crank.

New LA sleeves to go 1197 were $540, boring/installing/honing a 1015 block was $500. Porting and big valve a Z1 head was $750 (similar to Larry C's work) Boring upper cases is $160.

Then you have to add new valves, cams, pistons, bigger carbs, etc.
 
1978 KZ650B2 w 1197cc Z1 engine
1977 KZ650B1 w 750cc Spectre engine
1979 KZ650C3 w 831cc Hot Rod engine
1978 KZ650C2 w 762cc DFI project
1977 KZ650C1 stock restoration project
1978 KZ650B2 modified project
1978 KZ650B2 Injected Drag 831cc
1980 Z1 Custom Frame Drag 1327cc
1981 Z50R Honda tow bike
Last edit: 05 Mar 2024 11:24 by Injected. Reason: info

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Re: J motor max displacement

05 Mar 2024 08:59
#895993
Easy to double your build budget with these kind of delights 

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