Bob Lang wrote:
Hi,
Along the lines of thinner oil - try no oil at all in the dashpots. The
SCCA racers did this as a matter of course. I don't know why it works,
but it's probably a function of the carb response at WOT as opposed to
driving on the street where we hardly use any of the throttle (more or
less).
Great idea to check the dashpots, Vance.
rml
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Bob's right about not feeling the need for dashpot oil, once above 3000
prms, or so. By then engine vacuum is high enough so that the air valves
respond instantly to changes in throttle positions. At lower speeds this
rising must be slowed down with some kind of dashpot oil, or the air
flow will be too great, and will lean out the mix. The engine will of
course stumble.
My own tests using an air/fuel monitor confirms this. Even at 3,000
there is an initial drop in the mix, and is picked up by the monitor. So
quick as to hardly feel it in the pants seat. The engine will still
accelerate without this oil, but is doing so with a leaned-out mix.
More on this later in my reply to Shawn...
Dick
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