Vorn and Piston Orientation

[Kurt in S.A.]

I saw a post on another forum.  Owner of a '61 R27 can't figure out which way to orient the piston.  He said that the letters "vor" (should be vorn) are on the crown but no arrow.  Does the R27 have an offset on the piston?  Without the arrow, which way does the piston getting oriented?  My R25/2 shop manual says the arrow points in the direction of travel, but he needs an arrow...

Kurt

[Kurt in S.A.]

[DanMay]

Kurt,
See the picture below of an R27 piston. 
It reads  "  <--- VO"



https://picasaweb.google.com/lh/photo/f6zH345Mq6D5ke0e5jgc2SFJEdbAaQEO35ou6OtqX2k?feat=directlink

Daniel

[Kurt in S.A.]

Dan -

The picture is a little hard to make out.  I assume that the arrow points to the front of the bike and the "VO" letters are readable from which side of the bike?

It also appears that the R27 piston has pockets for the valves.  Can this be used to also orient the piston?  Is the intake valve bigger and thus the piston pocket would be bigger too?

Kurt

[† odeon8]

Hi Kurt,

the offset is to the right side if you sit on the bike.
You can measure it using a caliper - ca. 1,5 mm from the middle.

See also here.

Thomas

[Kurt in S.A.]

the offset is to the right side if you sit on the bike.
You can measure it using a caliper - ca. 1,5 mm from the middle.

Thomas -

So, you're saying that the wrist pin will be shifted 1,5 mm from the middle of the piston to the right as you sit on the bike?

Kurt

[27-steib]

Hi Kurt,

and Yes - Vorn means front.


Greetings Jan