Vapor lock could be a possible cause, except that he said he had tried 3
different carburetor setups and still had the problem, which would
essentially eliminate a carburetor problem as the cause.
Bob W.
----------
> From: Les Myer <lesmyer@geocities.com>
> To: spridgets@autox.team.net
> Subject: Re: Constant Speed Sputter
> Date: Friday, April 16, 1999 6:22 PM
>
> 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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