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Re: [Spridgets] SU question for racer types...

To: spridgets@autox.team.net
Subject: Re: [Spridgets] SU question for racer types...
From: fastvee <fastvee@yahoo.com>
Date: Sat, 13 Nov 2010 05:45:17 -0800 (PST)
I hadn't commented before now because there are just too many variables to
make any general statements. When I raced in H/P I used HS2's that were
through bored, had no dampers, and the air chamber springs were cut.  It idled
around 1000 rpm, could be driven through the paddock and did not hesitate or
sputter out of the turns. However, when driven properly on a road course the
rpm's hardly ever get below 4500. Doug Gutekunst and I spent an entire day on
his engine dyno tuning every aspect from cam timing and valve adjustments to
carbs, which is what made this possible.
My experience with my street 74 Midget carbs is that I can't do without the
dampers, and I prefer a slightly heavier oil. It does slow acceleration
slightly, but so far I haven't been able  to have smooth transition from idle
with lightweight oil. There is a video on youtube from someone whose
experience is directly opposite. He removed his dampers and taped the drive to
show no difference in smoothness. Don't think there will ever be one answer
carved in stone.
Fogelsville, PA

--- On Fri, 11/12/10, Mark Haynes <haynes386@netzero.net> wrote:

From: Mark Haynes <haynes386@netzero.net>
Subject: Re: [Spridgets] SU question for racer types...
To: spridgets@autox.team.net
Date: Friday, November 12, 2010, 3:35 PM

When we first bought the Spit racer, the HS2s on it were in this condition.
After talking with some of the Sprite/Spit racers, the conclusion that we
to was this- The dashpot dampers had been removed to 'help it accelerate
faster', since the dashpot dampers slow the rise of the dashpots.
It was flawed logic. All that removing the dampers did was to (as Kirk said)
cause the dashpots to rise erroneously fast leading to a huge lean condition
as it accelerated and a flat spot in the power curve. We played with heavy
weight oils, light weight oils and no oil and found (surprise, surprise) that
SU designed them pretty well and that using a lightweight oil (dashpot oil,
believe it or not) gave the best throttle response.
I know for a fact that John Twist advocates, nay, insists upon, using 90wt
in dashpots. His theory being how many times has that dashpot gone up and
in the 50 or so years that the car has been around, and how much wear has
there been on the interface? He has a point, and if you are just toodling
around town, you won't notice the difference, if you drive hard, who knows,
its mostly SOP feel anyway.
>From the work that I did with the Spit, I'd put another set of dampers in
use dashpot oil or 90 st whatever your gut tells you.
My experience and my $.02

Mark Haynes

Never heard of this as an intentional mod.  Unless someone
has installed a concealed electronic fuel injection.

But I have to ask..
1)How does it run presently?
2)Who took them out?

If it sputters and pops when you stomp on it then you just
found out why.

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