Electric fuel pumps for early Triumph
> Would like to install an electronic fuel pump as part
of the upgrade for my TR2 project and would be interested in
what brand and what rate of fuel delivery a pair of SU SH6 carbs
on a fast road motor might require. Would any old pump
a regulator was used, or should one get as close as possible
to the working pressures of the carbs alone. Should a fuel
be installed before the pump of after? Is the trunk the best
location for the unit(s)?
> Thanks, Dan
Kas Kastner says that you need 35 gallons per hour flow for
a race car.
The SUs need about 2-3 lb./square inch pressure to operate.
Insufficient flow can occur if you use a pressure regulator
set to regulate at the pressure that the pump puts out unregulated.
The Chief Boffin here at The High Speed Triumph Research Laboratory
has experimented with this phenomenon. Makes the car run terrible.
Want trouble with a fuel pump line, just run too much pressure with S U 's.
Try 2 pounds and then check to see that the pump will deliver 15 gallons per hour. Easy to do, no excuses.
Listers, For street brit cars a more reliable pump I found was a mitsubishi for a 1984 Honda Accord. It fit under the ls floor along rocker and even sounded like an SU style. It has points but does not seem to be affected by sitting around. Around 2psi if I remember. Was 85.00 new last time I checked. Have not bought one in a while.
Electric Fuel pumps & pressure regulators
> After fighting all weekend with my fuel issues I am thinking it is the Holley regulator. Actually Jim Norlin though of it.
It broke on me a year ago at this event. It seems to be the only one that is 1 to 4 psi that I could find. Looking for input.
If my memory serves me we want to run 3.5psi with my SU HS6 carbs. Any thoughts on the regulator/ fuel pump??
I use a Holley red low pressure pump with a Mr. Gasket cheap regulator dialed down to 1.5 and it works great. We are using the same carbs as you. We used these regulators on VW off road cars to keep the pressure down so as not to flood in rough terrain. The Holley regulators might not be as sensitive at lower pressures. 3.5 is high I think.
Vintage Auto Service
Use the Holley Blue pump (about 15 psi output as I recall) with the Holley regulator - either the 1-4 psi regulator or the 4-7 psi regulator. If you use a low pressure pump you won't have enough pressure differential to properly actuate the regulator. Jack and I went through many permutations of pump / regulator before we found the reliable fix to the problem. I run a rock solid 2 psi to my Webers with that set up.
Group: Tony is dead on in his assessment. We had the same issue in the now Randy Williams TR3. The Holley red only puts out 4 psi, and as you try to adjust a Holley regulator down to 3-3.5 psi there isn't enough of a pressure differential to let the diaphragm work properly. The fix is to move up to the Holley blue, and adjust the pressure to the desired level. On this topic...most of us (read carb equipped) want pressures in the area of 2-3.5 psi. All the pressure gauges I can find read 0-15 psi. This puts us using them in the lower 25-30% of the gauge which is not the desired area to be reading. Has anyone been able to find a gauge that reads 0-5 psi? I have looked all over, including aircraft supply places, with no luck.
I used the blue pumps are regulators with great success. Some of the little electronic pumps were okay for a while but, they in the end, failed at a time of great nuisance. Pressure, volume and adjustability, from blue pumps. I have used AC motor pumps and they worked very well also.
I'm always a friend of simple solution. Less parts on the less failures you might face. I run a Mitsuba fuel pump. The is self regulating and suitable for SU and Weber.
I've used Facet pumps for a while now and they do eventually pack up, mostly due to moisture collecting inside the steel body and causing the electroplating to variously fur up .... I ditch them after 3 years in the car as 5 years seems to be the maximum service life. Otherwise so long as you put 12 volts and fuel through them they pump enough to keep up to 2 weber 48s happy.
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