Charles,
My understanding is that with a heavier oil the piston rises more slowly
such that the venturi opening is smaller in ratio to the throttle plate
opening than it would be with lighter oil. The smaller venturi opening
draws more fuel per air volume enrichening the mixture during rapid
acceleration, which is when you need it. I believe your are correct that
constant speed is not the issue.
This is my un-educated, non-degreed conception of the process. I'm sure
there are more lucid descriptions available among listers. Why are you
going through so much oil? Our technique at a dealership I worked for was
to fill the dampers, screw on the top, push the carb piston up, and
whatever squirts out of the vent hole and into your eye shouldn't have been
there... what is left is the correct amount.
YMMV Peter C
--
At 09:36 AM 3/13/2000 , Charles D. Sorkin wrote:
>But what is confusing me is that unless the spring is going bad, the piston
>ought to remain at the same level while at a constant speed. Since my
>dashpots go through half of their oil in about a week or two, I'll be
>experimenting. A representative from a local parts vendor suggested using
>ATF, so that if a problem developed that caused dashpot oil to be consumed
>rapidly, the resulting smell (stench) would indicate the driver.
>
>If the oil is too thick, doesn't it also impede performance by making the
>mixture adjust more slowly?
>
>As for the 3-in-1 that I use, its best feature is that it comes in a small
>can that fits conveniently behind the frame member in the boot.
>
>Regards,
>
>Charles
>'74 Midget
>'68 Sprite
>cdsorkin@ix.netcom.com
>Bloomfield, NJ
>
>
>
>-----Original Message-----
>From: shawn tobin <suhs2@hotmail.com>
>To: cdsorkin@ix.netcom.com <cdsorkin@ix.netcom.com>
>Date: Monday, March 13, 2000 9:43 AM
>Subject: dashpot oil
>
>
>>I have used Marvel Mystery Oil like some suggest but I believe it to be too
>>thin and allows the carbs to flutter. My car seems to run best with 20W50
>>synthetic in the dashpots. This weight of oil is recommended in the
>Bentley
>>manual and in owner's manuals. You may like a lighter grade but some
>weight
>>of motor oil works best for me.
>>
>>Also, on constant speed question, I have done a couple of the Vizard mods
>on
>>my carbs to increase airflow. After modding them, I put straight Marvel in
>>them and adjusted the mixture for idle. I found a sputtering flat spot at
>>2000 to 3000 rpm even at constant speed. Richened the mixture nuts--same
>>problem. Put in 30wt and the problem subsided. Now I'm back to 20w50 and
>>the car runs great. Don't exactly know why.
>>
>>PS get some Royal Purple--you'll love it.
>>______________________________________________________
>>Get Your Private, Free Email at http://www.hotmail.com
>>
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