650Rider, xs650 hosted by XS650.com

What Happened to 650rider.com?

650 Rider went offline for about a month at the beginning of 2010. In order to save the technical information that was here, XS650.com acquired the site and brought it back online as a read-only archive. If you were a member of 650 Rider, you will need to re-register at XS650.com

     [x] 650Rider Menu
 Community Search Information


xs650 > > Motorcycle Systems > > Engine > > 256 Engine Parts Measurements

SearchSearch


256 Engine Parts Measurements
    Forum Index -> Engine
View previous topic :: View next topic  
Author Message
ZouLou
Full Member
Full Member


Joined: Jun 01, 2008
Posts: 15
Location: St. Louis/Columbia MO

PostPosted: December 27, 2009, 9:46 pm    Post subject: 256 Engine Parts Measurements

Does anyone have a 256 piston and rod lying around? I could really use rod length measurements (hole center to hole center if possible) and on the piston a wrist pin hole to top edge of piston. I have a attached an image od the two measurements i need.

I need measurement C or A, B and Hole to Hole



I also need measurement A in this picture

Back to top
despecial
Full Member
Full Member


Joined: Sep 26, 2009
Posts: 232
Location: D20000

PostPosted: December 28, 2009, 5:37 am    Post subject: Re: 256 Engine Parts Measurements

A....22mm piston wrist pin
B....34mm big end
C..136mm con rod centre to centre
D..?

A..?

_________________
Most motorcycle problems are caused by the nut that connects the handlebars to the saddle.


Last edited by despecial on December 29, 2009, 12:40 pm; edited 1 time in total
Back to top
ZouLou
Full Member
Full Member


Joined: Jun 01, 2008
Posts: 15
Location: St. Louis/Columbia MO

PostPosted: December 29, 2009, 1:19 am    Post subject: Re: 256 Engine Parts Measurements

Thanks a whole lot for those measurements. I am ordering a custom piston from Venolia and I think the pin placement is set for a 256 engine. I know the pin hole size is for sure. Here is the piston drawing.

Back to top
despecial
Full Member
Full Member


Joined: Sep 26, 2009
Posts: 232
Location: D20000

PostPosted: December 29, 2009, 9:12 am    Post subject: Re: 256 Engine Parts Measurements

you should also be able to fit a complete crank-rod-piston assembly from a later model motor
_________________
Most motorcycle problems are caused by the nut that connects the handlebars to the saddle.
Back to top
yamaman
Support Staff
Support Staff


Joined: Jan 04, 2007
Posts: 1638
Location: Perth Western Australia

PostPosted: December 29, 2009, 9:46 am    Post subject: Re: 256 Engine Parts Measurements

Despecial, you've put down the big end as 26mm pin.
Big end internal diameter is 34mm I think...........(well it's a 26mm pin & 34mm rod on the 447's anyway)

Edit: Just looked at Mikes, bearings suit all motors, so rod big end is 34mm.

_________________
Its not enough to have an aim in life, you have to pull the trigger!
Back to top
Photo Gallery
despecial
Full Member
Full Member


Joined: Sep 26, 2009
Posts: 232
Location: D20000

PostPosted: December 29, 2009, 12:39 pm    Post subject: Re: 256 Engine Parts Measurements

youre right-ive just checked my table and ive given the crank pin diameter not the big end...will edit the post
_________________
Most motorcycle problems are caused by the nut that connects the handlebars to the saddle.
Back to top
ZouLou
Full Member
Full Member


Joined: Jun 01, 2008
Posts: 15
Location: St. Louis/Columbia MO

PostPosted: December 29, 2009, 5:37 pm    Post subject: Re: 256 Engine Parts Measurements

OK here is the whole story with this question. I have a '79 XS650 engine. I got a head ported by 650performance.com. The porting was designed by Harry Lillie and the Venolia pistons were designed by him too to work specifically with his head porting. I am going to get a set of Carillo rods made for my application to ensure max rod strength. So looking at the piston design I realized they are set up for 22mm pins which come on the 256 engines. According to Craig Weeks the 256 rod and piston were preferred by top tuners for their dwell time at TDC. I am hoping to get the Venolia pistons and then use 256 sized rods and have it all work together with my rephased 447 crank. Any help or suggestions is greatly appreciated.

-Kyle
Back to top
Display posts from previous:   
Printer Friendly Page     Forum Index -> Engine All times are GMT - 5 Hours
Page 1 of 1


Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You cannot download files in this forum


   

Check out the new Honda CB750 Forum at CB750.com! A site dedicated to the great Honda SOHC and DOHC CB750.

Check out the new Yamaha XS400 Forum at XS400.com!

Yamaha xs650

xs650, xs, 650, forum, links, chopper, custom, yamaha, parts, forum, info, information, bb, bulletin board, XS650
650Rider, Free Unrestricted xs650 forum, Personal photo albums, Post images in Forum, News columns, Daily blog, Links, Event calendar, Information for Yamaha XS650



Interactive software released under GNU GPL, Code Credits, Privacy Policy