Wednesday, July 14, 2010

Lesson

5 1/4 stroke, rpm´s @s 6,500 on 15 runs over a couple of days.
Day 3 and during the burnout the rear exhaust valve decides it is time to retire.
Steel pieces of which the largest is about 3mm leaves the edge of the valve

and are in a hurry to get out. The valve doesn´t quite close when the pieces are leaving so the pushrod leaves the ball on the rocker arm and now hits the ball with the edge of the pushrod cup. and with very limited travel to coil bind that is exactly what happens, and something has to give...this time it is the rocker arm at the
spring end.

I will miss this rocker arm, it has done a good job and had bushings in both ends.
I have a spare one already prepared which mr Baisley did the roller on, not bushed on the spring end, but it should not be a problem these days after i learned to adjust pushrods with generous clearance.
To little and the knuck will starv for oil on the shaft at the spring end when clearance is eaten up by the hot valve, and with hard springs and steel to steel it seizes on shaft.


The valve is a 5/16 stem 1,800" but somewhat taken down on the dia.
I used a S&S S B2 head exh.valve to start with and reduced thickness on the disc and the dia , cut the groove and then the stem to the right length. 



New S&S valve on the left and the reduced new valve is right.






Ok i got a valve and a rocker arm

I have not decided if I should go into a full head rebuild with guide replacements and the rest, or just put it togheter which should be ok and then do the zerosetting coming winter, there is still three races left this season.

Will exhibit in the "Back to Basic" races at Mantorp last week of July, after that we have championship races first weekend of August in Lindesberg, and after that it´s Mosten Raceday/Denmark in September, Mosten is end of season, great music and gigantual party.

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Reception

Reception
I.m a gasoline molecule on my way to work....

Mystery Oil.........

Mystery Oil.........
Just a spoonful to the assembly lube.

Remote Starter

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