Thank YOU, Bill.
Am putting the BBW info. "in the file".
for reference when the time comes.
Yes, air moves faster than liquid
as your foot goes down and the air
valve opens for acceleration.
Slower rate of opening allows a little
more "fuel to air" as engine accelerates
while a thinner oil allows the air valve
to open faster, allowing more "air to
fuel" under same engine demand.
"Balanced" by":
spring stiffness determines air valve opening at any given engine
"demand"
and is "matched" so that air valve reaches maximum travel in the "open"
position at engine's maximum rpm. If it's
fully open before that, mixture leans out
at towards top rpm. If spring is too stiff, the carb. never fully opens
for max airflow
and top end power and the entire application runs a little richer
throughout the entire curve below
that point in the rpm curve wherein the
air valve reached full travel.
The spring rate is important for racing or constantly driving around
with your foot
"in it". Otherwise, a red spring for the
average 1275 with anything less than Stage 3 tuning seems to be the
choice
with a BDL needle. But I'll look up the
difference in profiles between the BBW
and BDL and will probably start with the
leaner and work along from there.
Can't have too much information when
doing a conversion the first time around!
Thanx, again. C'ya and happy Spriting.
Cap'n. Bob
'60 :{)
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Date: Wed, 07 Aug 2002 09:45:07 -0500
To: PilotRob@webtv.net (Robert E. Shlafer)
From William Cantrall <cantrall at wrcresearch.com>
Subject: Re: 5000 miles in a Bugeye
Cc: spridgets@autox.team.net
>
References: <William Cantrall <cantrall@wrcresearch.com>
Cap'n. Bob,
The BER has a much leaner profile at mid to high revs and it felt pretty
weak at those revs as well. The BBW is much better at mid to high revs.
Thanks for the suggestion on the damping oil! I will give that a try.
Bill
At 23:30 08/06/02 -0400, Robert E. Shlafer wrote:
>Thankyou, Bill.
>
>I used to think a 1.75 was a bit much
>for the stock cammed older 1275's
>though the "newer" (different cam?)
>1275's all come with the this carb.
>according to Dave Anton (APT)
>
>The "coming up on the cam" effect sounds
>like an intially lean acceleration "circuit"
>(flat spot?) in view of the fact the cam is stock and the BBW choice
>otherwise sounds pretty much right according to
>your plug color observations.
>
>Of course, going to a heavier weight oil
>in the damper would test for the foregoing
>in a heartbeat.
>
>May I ask what prompted you to replace
>the BER needle with the BEW in the first
>place? Did you notice an obvious "fault"
>using the former needle?
>
>Again...appreciate the feedback! :)
>
>
>
>
>Cap'n. Bob
> '60 :{)
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