Sounds like vaporlock at the rear carb to me (from heat).
Try this. Install a fuel bowl top from a front carb on the rear carb. Now
you have an outlet for a fuel return line, similar to what was seen on most
air conditioned cars of the 70's. Run metal fuel line back to the tank -
you will have to make a fitting to dump the gas back in the tank. Install
a restrictor in the rubber hose that leads from the rear carb to the new
metal fuel return line. This can be made from a short section of metal rod
and a very small drill bit, and will control the rate of flow back to the
tank. Too big and you will loose pressure. Too small and it won't be
effective. Shove this in the hose and put a hose clamp on it to keep gas
from leaking by.
I did this same kind of trick with the Holley carb on my 355 C.I. Chevy
Monza. It was boiling the fuel in the secondary fuel bowl (fell flat on
it's face when you opened the secondaries - after driving at speed). this
fixed the problem. Tapped the rear fuel bowl and installed a fitting.
Fotunately I was able to use the vapor return line for the fuel return line
(vented the cap with a drill bit).
Some cars have poorer air flow through the engine compartment itself, at
speed. This Monza was definitely one of them. I have noticed that
Spridgets seem to run quite hot when you get past about 70MPH, for any
lenght of time - no apparent reason.
Another trick I have used is to wrap aluminum-faced tape around the (very
heat-absorbing) black rubber fuel lines. Makes a difference.
Les Myer
At 08:51 AM 4/16/99 -0700, you wrote:
>I have posed this puzzle to the list before but since we have a lot of new
>people I thought I would try it again.
>
>The engine in my Bugeye runs great 99% of the time. When driving at a
>constant speed in 4th or 5th above about 3500 RPM it will occasionally start
>to sputter real bad.
>
>If I let off the throttle, press the clutch, and let to RPM's drop to idle,
>the miss goes away. No other action will make it stop. I've tried less
>throttle, more throttle, etc. and it just keeps sputtering until I let it go
>to idle.
>
>This happens randomly but always under the same conditions. It never happens
>around town in stop and go driving, only on the open road. Some times after
>a mile or so, some times after 20 or 30 miles, some times never.
>
>This engine has been in two different cars with different fuel and wiring
>systems.
>
>One car has a new gas tank with all new 1/4" gas lines and the other has a
>"renu" gas tank with all new 5/16" gas lines.
>
>The following components have been installed in just about every possible
>combination:
>
>1. Three different carburetor and manifold setups, 1.25 SU's, Weber DGV
>downdraft, and Weber 40 DCOE.
>
>2. Two different distributors, a stock vacuum advance and an Aldon Yellow
>centrifugal advance.
>
>3. Three different fuel pumps with and without a fuel pressure regulator at
>various pressure settings.
>
>4. Three different coils, a stock Lucas coil with external ballast, a hot
>Crane coil with external ballast, and a Lucas
>sport coil.
>
>5. Various types of plugs, plug wires, points, distributor caps, rotors,
>etc.
>
>
>
>
>
>Larry Miller "A Fool (For LBC's) And His Money Are Soon Parted"
>59 Bugeye (Being Ripped Apart)
>60 Bugeye (Willie Nelson)
>78 911 SC Targa (Faster than a Bugeye but not as much fun)
>Home Page http://ado13.com
>Spridget List Member Input Form http://ado13.com/listinfo.html
>Spridget List Member Info Page http://ado13.com/list/email/files/list.htm
>
>
>
>
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