Jack wrote:
>Strombergs - when tilted so gas is on the RIGHT side
(simulating a >left hand corner), the floats droop and never shut off
the gas -- it leaks
>out the jet tube.
That certainly squares with our experience. We're not getting a
sputtering on long high-g left-handers, we're getting a sudden loss of
power, which shows up immediately on hard left-handers, accompanied (I
am told) by a gas odor.
We're also running out of revs at around 4500, but that's probably
another cause.
Scott
> -----Original Message-----
> From: Jack W Drews [SMTP:vinttr4@geneseo.net]
> Sent: Saturday, January 30, 1999 2:45 PM
> To: FOT@autox.team.net
> Cc: vinttr4@geneseo.net
> Subject: Fuel Systems - Strombs vs SU's
>
> I have run Strombergs for three years, and Joe Alexander has run them
> for six years, I think. That doesn't mean anything other than that I
> have a keen interest in advancing my knowledge of the diffences in
> performance between Stroms and SU's.
>
> I made a number of measurements this afternoon using
> Stromber 175 CD's and 1-3/4" SU's with the float bowl with the central
> bolt and cylindrical float. What I discovered was interesting to a
> technofreak like me and maybe it will interest you, too. This is a
> long
> message so please delete NOW if you're not interested.
>
> Chamber capacity: For purposes of the measurements, I ran the Stroms
> the
> way I race them -- with the floats set as high as they will go and
> still
> shut off the fuel. I set the SU float to factory spec, not knowing
> what
> the current SU users do. Under these conditions, the Stormberg chamber
> holds 31 cc and the SU 21 cc -- and this is with the carb tilted as
> installed on the engine. The Strom holds 7 more cc not available to
> the
> jet because of the tilt.
>
> However, what happens during cornering? As an appoximation of
> cornering
> conditions, I assumed that the fuel in the chamber is tilted at a 45
> deg. angle, and measured chamber capacity with the carbs tilted 45 deg
> left and 45 deg right.
>
> Results:
>
> Strombergs - when tilted so gas is on the RIGHT side (simulating a
> left
> hand corner), the floats droop and never shut off the gas -- it leaks
> out the jet tube. When tilted so the gas is on the LEFT side
> (simulating
> a right hand corner) the floats shut off the gas and the chamber
> contains 12 cc. This is because the pivot for the Stromberg floats is
> on
> the right side.
>
> S.U.'s -- when tilted so gas is on the RIGHT side (simulating a left
> hand corner), the chamber contains 38 cc. When gas is on the left side
> (simulating a right hand corner) the chamber contains 31 cc. Under
> both
> conditions, the float and needle valve shut off the fuel.
>
> End of data.
>
> I've tried to present just data without comments so now here comes
> some
> real world experience. In the Alexander and Drews cars, we do not
> experience the deterioration of performance in right hand corners that
> the above measurements would seem to predict. The data above would
> indicate that the engine should starve but it doesn't seem to. When
> exiting a left hand corner, specifically #5 at RA, the Drews car
> sputters but the Alexander car does not. The Drewses have attributed
> this to other factors but maybe it's excess fuel.
>
> I would expect the same situation of shutting off or flooding to be
> true
> of any carburetor with side-pivoting floats, wouldn't you?
>
> And finally, this all confirms what Hero Drivers the Alexanders and
> Drewses are, to be running so fast with carburetors that don't
> work.........just wait till next season.....
>
> --
> uncle jack
> 61 TR4 Rallye Replica Racer
> Diligently Engineering My Way to the Back of the Pack...
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