74 z1 piston to head clearance

canadien
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19 Jun 2015 05:26 #677241 by canadien

74 z1 piston to head clearance was created by canadien

Hello I'm new to this forum.
Im rebuilding a 1974 z1 900. I got the block bored to 69mm and the machine shop also had to machine the deck. I would like to check piston to head clearance and valve clearance. Anyone here know what tthe minimum piston to head clearance is for street use?

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531blackbanshee
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19 Jun 2015 06:04 #677246 by 531blackbanshee

Replied by 531blackbanshee on topic 74 z1 piston to head clearance

i would want at least .045 thousandths between the piston and head and .080 between the valves and the piston.

imho,

leon

skiatook,oklahoma 1980 z1r,1978 kz 1000 z1r x 3,
1976 kz 900 x 3
i make what i can,and save the rest!

billybiltit.blogspot.com/

www.kzrider.com/forum/5-chassis/325862-triple-tree-custom-work

kzrider.com/forum/5-chassis/294594-frame-bracing?limitstart=0

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SWest
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10 22 2014

19 Jun 2015 07:22 #677257 by SWest

Replied by SWest on topic 74 z1 piston to head clearance

How much did they take off the deck?
Steve

Z1b1000 1975 Z1b
kzrider.com/forum/11-projects/598262-kz-...-will-it-live#672882
kzrider.com/forum/2-engine/597654-poser?start=240#704229

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canadien
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19 Jun 2015 08:06 #677260 by canadien

Replied by canadien on topic 74 z1 piston to head clearance

They removed. 020" I haven't checked the clearance yet

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SWest
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10 22 2014

19 Jun 2015 09:13 #677269 by SWest

Replied by SWest on topic 74 z1 piston to head clearance

From the head or barrels?
Steve

Z1b1000 1975 Z1b
kzrider.com/forum/11-projects/598262-kz-...-will-it-live#672882
kzrider.com/forum/2-engine/597654-poser?start=240#704229

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canadien
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19 Jun 2015 09:28 #677272 by canadien

Replied by canadien on topic 74 z1 piston to head clearance

From the barrels, the head has not been machined at all

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531blackbanshee
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19 Jun 2015 11:37 #677284 by 531blackbanshee

Replied by 531blackbanshee on topic 74 z1 piston to head clearance

prolly be just fine .

always nice for the piece of mind to check tho. :cheer:

leon

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SWest
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10 22 2014

19 Jun 2015 14:10 #677302 by SWest

Replied by SWest on topic 74 z1 piston to head clearance

69mm, Are they J pistons? High compression?
Steve

Z1b1000 1975 Z1b
kzrider.com/forum/11-projects/598262-kz-...-will-it-live#672882
kzrider.com/forum/2-engine/597654-poser?start=240#704229

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canadien
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19 Jun 2015 15:06 #677311 by canadien

Replied by canadien on topic 74 z1 piston to head clearance

Whoops I said 69mm actually they are 68mm and the compression ratio before machining would be 9.25 or 9.5 to 1. Really all Im asking is what is the minimum clearance before the piston would hit the cylinder head.
J piston? Are you talking about the newer J engine? If so it is not a J engine.

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canadien
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19 Jun 2015 15:10 #677313 by canadien

Replied by canadien on topic 74 z1 piston to head clearance

I just checked again. Actually they are 69mm pistons

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SWest
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10 22 2014

19 Jun 2015 15:14 #677314 by SWest

Replied by SWest on topic 74 z1 piston to head clearance

Mine are 70mm. That's stock 1015. The J's had slightly smaller pistons but higher compression with a different head. I don't have the specs but I'm sure one of our members do.
Steve

Z1b1000 1975 Z1b
kzrider.com/forum/11-projects/598262-kz-...-will-it-live#672882
kzrider.com/forum/2-engine/597654-poser?start=240#704229

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74 z1 piston to head clearance

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