?'s Fuel Pin
#3
#4
#7
I want to take some internal VE measurements or cut a couple observation holes in my pump top first before making up my mind.
There's a limit to the amount that a fuel cone grind can get you. That limit is determined by the amount that the fuel pin can travel before the AFC arm contacts that case or whatever it contacts that limits its travel.
I've heard years ago that there wasn't much if anything to be had by going deeper than what could be had by grinding the stocker; the pin that rides on the cone simply can not move out that far before the arm hits. Which is exactly why you can't just shorten the pin that rides on the cone instead of cutting the cone deeper.
Old school thinking is that the only way to get full AFC actuation along with AFC control is an extended cone, like DennyT's, a ground AFC lever, and a longer pin connecting the two. Or to do something radical like putting a pneumatic actuator directly onto the AFC lever through the case.
A lot could be accomplished in the world of tuning these pumps with some strategically-placed holes and pipe plugs, to see exactly how far the throttle lever is moving, exactly how far the AFC arm is moving, and exactly how far the control sleeve is moving. The first two could be tested dry, the last one would require looking through a Lexan pipe plug on a dyno.
#9
A witness mark along the entire face of the cone could be taken to mean a constant contact with the AFC lever.
It could also be explained due to the case pressure pushing out against the pin.
If there is something to be had by having that deep of a cone, then I don't see how that wouldn't mean there wouldn't be an equal amount to be had by grinding 1/8" off the pin?
It could also be explained due to the case pressure pushing out against the pin.
If there is something to be had by having that deep of a cone, then I don't see how that wouldn't mean there wouldn't be an equal amount to be had by grinding 1/8" off the pin?