Original part numbers (Rotor Arm)

[mgm]

Hi,

I have a new (Bosch-GSF) rotor arm that is slightly different to the existing one (Bosch-Halfords), but identical to an old one? My Van is a 1980 T25 2lt Aircooled twin Solex all original CU engine code (Oh and sorry not for sale).
The main differences are the lengths of the brass wiper that contacts each of the 4 positions on the dist cap. Therefore this would effect how long the spark is there for each cylinder and therefore if the combustion was complete or not.

How do I know which is the exact one as per OEM VW? Does anyone have the part numbers or a suggestion where I can find out?
My Bentley and Haynes don't satisfy this request....

Even looking on the dark side they list two versions that could fit a T25 1980 2lt VW????

Thanks.

[Grun]

mgm,
Since no one has replied, and although I have no answer to your request for specific part numbers for your rotor arm, your fears about the difference in the length of the brass portion of the rotor arm affecting the duration of the spark are in my opinion unfounded. Many other factors determine the spark timing and duration.
The VW flat four in all its forms has been around for about as many years as me, and is a pretty basic bit of kit able to operate quite well with a lot of alternate parts.
Don't worry if it works enjoy it.

Mike

[Aidan]

1980 CU rotor arm should be 071 905 225 A 5400rpm and a frightening £16.50 plus vat from VW