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Old 03-25-2013, 02:08 AM   #590
LukasM
Beastly Adventurer
 
Joined: Nov 2006
Location: On a RTW ride - currently Central Asia
Oddometer: 5,352
Quote:
Originally Posted by Pete640 View Post
Ok so its a very busy night at work tonight so I thought what better way to constructively use my time than do a little research. Knowing the 690RFR motors are actually 654 (IIRC) and knowing that KTM has made the 690 Enduro a true 690 cc motor I thought - is it possible???

Onto the Boltons KTM parts fisch I go.....
1st - the base gaskets for the RFR bikes and the 2012 Enduro are the same PN (75030035000),
2nd - the head gaskets are the same PN (75030036000),
3rd - timing chains are the same PN (75036013000) B2, 104 links, 07
4th - wrist pins are different PN's but they are both 20mm,
5th - timing pullys are the same PN (75036014000).

Obviously the cylinders are different as are the pistons/rings. Cylinder heads are different as well but I expected that, the RFRs being a higher performance possibly? (But they use the same valves, both intake and exh - same PN's). My reasoning is that if the gaskets are the same PN the water galleries, chain and guide caverties and oil passages should all line up???

This leads me to think that it would be possible to use the 690R "big bore" cylinder and piston on the RFR bikes. Can anyone shoot a big fat hole in my logic? More CC's = more kapow right???
The 2012 690 models get their increase in CCs from a crank with 84.5mm stroke instead of 80mm, the bore is still the same 102mm as the 654cc models have. The long stroke crank should come with a shorter rod, so it could probably be put into the Rally engine with the rest of the parts staying the same. However you'd have to do some head work to keep compression with same with the increased stroke.
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