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Bore size
Posted: Mon Sep 07, 2009 12:01 pm
Author: martinz1000r
Just had a thought whilst engine is back in bits prompted by reading back through Pigford's Lawson project. Thought if I need a new set of rings best I be 100% on cc before I splash cash. This motor was sold with suggestion that it is 1260cc. Bore sizes are 76mm.
What does this make the engine as I think 78mm was 1260?
Posted: Mon Sep 07, 2009 12:09 pm
Author: martinz1000r
oops! should have been in Bike help! Accurate measurement 75mm. 1170cc?
bore vs stroke capacity
Posted: Mon Sep 07, 2009 12:36 pm
Author: KWACKERZ1
z900 is 66x66 bore and stroke.
to calculate cc
Bore area is therefore 6.6 x 6.6 x 3.14159 / 4 = 34.20 square cm.
Volume of 1 cylinder is bore area times stroke = 34.2 x 6.6 = 225.7cc
As there are 4 cylinders in the engine the total engine volume is 225.7 x 4 = 903 cc
Therefore 75mm is
7.5 x7.5 x3.14159 /4 = 44.17
44.17 x 6.6 = 291.57 each cyl so x4 =1166.31 (1170)
Hope this helps.
Phil
Posted: Mon Sep 07, 2009 12:39 pm
Author: Al
http://www.wiseco.com/ProductDetail.asp ... AppID=7914
http://www.wiseco.com/ProductSearch.aspx
1166 or 1170 dependant on wrist pin diameter for 75mm bore. Which should make it the 1171 kit i think or the other one if 18mm pins! Confused?
With the unitrak head and those high top pistons combustion chamber volume will be between 29 and 31 ml which is = 29-31 cc.
Unlike what it says in the listing above this will probably put the compression ratio nearer to 11:1 than that stated.
If you're buying rings you might want to think about a base gasket spacer too.
Debbens do rings from stock i believe as do Gremlin Racetech and others.
Need to measure the outer diameter of the skirt of the protruding liners before placing an order for a base gasket spacer but if they're 1089 stamped barrels there is no reason to suppose the liners have been changed.
As you say the pistons at 75mm will dictate the cc of the motor.
You will probably also need the stamped code from the crown of the piston to order the rings since there are several variants; XA XC XG
http://www.debben.co.uk/acatalog/GPz1100.html
http://www.gremlinracetech.com/
Hope this helps.
AL
Posted: Mon Sep 07, 2009 12:53 pm
Author: KWACKERZ1
Just a thought if its a a z1000 THE BORE IS 69.4 STD AND THE STROKE IS STILL 66.
Posted: Mon Sep 07, 2009 12:56 pm
Author: Al
KWACKERZ1 i think he said its a unitrack 11 motor from standard in the other post about coils.
AL
Posted: Mon Sep 07, 2009 1:04 pm
Author: martinz1000r
It is a Unitrack engine.
Thanks for all the help!
Martin