View Full Version : Crankcase opening dimensions needed ?


Mohawk
October 26th, 2016, 09:20 AM
Hi Guys,

Does anyone have a 250 crankcase minus its block at the moment that they could measure for me ?

I need the width of the cylinder base openings left the right & front to back, I assume both sides are the same.
Plus I need the web thickness between the holes.

if anyone happens to have a 250 piston complete with rings & wrist pin that they could weigh accurately it would be appreciated. I have found a note somewhere that they are around 167grams complete, just need that confirmed.

Thanks

Chris.

garth285
October 26th, 2016, 12:53 PM
will any measurements from a 08-12 engine help you?

Mohawk
October 26th, 2016, 02:48 PM
I believe the crank cases are the same on the pre-gen & next-gen, so yes that should be fine. Thanks

Mohawk
October 29th, 2016, 03:23 PM
Bum, any joy with the Tahoe measure ?

Petrolh34d
November 20th, 2016, 09:17 PM
I'll see if I can be of assistance

Mohawk
November 21st, 2016, 12:30 AM
I'll see if I can be of assistance

Many thanks Petrolh34d.

Mohawk
November 25th, 2016, 08:13 AM
BUMP

bruce71198
December 6th, 2016, 11:27 AM
BUMP

Do you still need these ?

Mohawk
December 6th, 2016, 12:43 PM
yes please

Mohawk
December 9th, 2016, 10:03 AM
Come on you teasers, someone must have one in bits. Also need the thickness of the bridge between crankcases.

Mohawk
December 17th, 2016, 02:56 AM
Bump

bruce71198
December 17th, 2016, 01:21 PM
Bump

https://www.ninjette.org/forums/picture.php?albumid=1160&pictureid=13096

https://www.ninjette.org/forums/picture.php?albumid=1160&pictureid=13097

I'll weigh a piston assembly and post later.

bruce71198
December 17th, 2016, 02:01 PM
Come on you teasers, someone must have one in bits. Also need the thickness of the bridge between crankcases.
https://www.ninjette.org/forums/picture.php?albumid=1160&pictureid=13098

https://www.ninjette.org/forums/picture.php?albumid=1160&pictureid=13099

That's the piston, pin, circlips and rings.

Mohawk
December 18th, 2016, 01:19 AM
Hi Bruce, thanks for those, much appreciated.

Mohawk
December 20th, 2016, 10:51 AM
So as I suspected, my new big bore liners will need a little metal removed from the left & rights sides where the liner cutouts are, but loads of room front to rear.

Thanks for the complete pisyon weight too. My big bore ones will weight 180 grams complete, (132gm bare), so 20 grams up on stock, but still lighter than the JE (139gm bare) or Wiseco (152gm bare) versions, which appear to work with stock rods.

Anyone know how deep the cylinder cut outs are in the side walls of the crankcase ? By that I mean from the top gasket face to the bottom of the scolloped area.

Mohawk
December 22nd, 2016, 09:52 AM
Just an avatar test

bruce71198
December 23rd, 2016, 11:11 AM
how big are you boring this engine?

Mohawk
December 23rd, 2016, 12:50 PM
66mm for 282cc using ZZR600 liners but having had them fitted to a spare block, then discovered the 250 liner is narrower at the bottom.

So thanks to your help, I now know I need to widen the cutouts slightly left to right, but they are fine front to rear. Then I remembered that the new liners are 3mm taller than the 250's so need to know if I need to trim the length !

dcj13
December 25th, 2016, 12:07 AM
Your avatar pic looks just like your profile pic.

bruce71198
December 27th, 2016, 05:24 PM
66mm for 282cc using ZZR600 liners but having had them fitted to a spare block, then discovered the 250 liner is narrower at the bottom.

So thanks to your help, I now know I need to widen the cutouts slightly left to right, but they are fine front to rear. Then I remembered that the new liners are 3mm taller than the 250's so need to know if I need to trim the length !

I widened the cases with a die grinder and carbide bit. It was relatively easy and didn't take to long. 3mm should clear the crank, if not clearance it with the die grinder.