Dellortoman said:
If you had been more attentive young man, you would have noticed the differing drive ratios!
Checked the OR600 part #s, 41 111 305/306 are the respective gears, used solely in this application.
Bob, I too have not found any reference to a special "Formula" pump. Can only guess it was introduced at a later date and therefore not included in the early parts lists. The data I posted was worked out by Mr. Witt and myself many years ago. He had done the triples as well as the 500/Formula pumps, I added the 600 data.
The Zane pumps have 15 and 12 teeth respectively, both 15mm wide. The high-volume 12T is from the air/oil cooled 668, the water cooled 750 shitpile got a slightly decreased circulation volume. Again with the same shaft centre dimensions and the gear pitches echoing the earlier 12 and 15T items.
piet
