There is some controversy over the need for relatively low fuel pressure in the Webers (2.5#-3#). Is this caused by the inability for the needle/seat fuel valve to control pressures above this? Are the current valves suspect/faulty? Several years ago a company (D & G valve) made a product called a Grose-Jet that was heavily advertised in Autoweek and other publications. I have never used them, but they are said to help with fuel control, anyone use them before? Said to work well in the old SUs on the British cars. Anyone experience or have concerns with current OEM Weber fuel valves?
Fuel pressure & supply
- Thread starter Rick
- Start date
Ron Earp
Admin
Everybody I know that runs Z race cars use the Grose-Jets. Including me. Also popular in the Strombergs found on TR8s, Jags, and Jensen Healeys. Essentially all it is is a trapped steel ball that can seat and act as a valve. Seems to deal with pressure fine, I run about 5.5 lbs of fuel pressure on my Hitachi flat tops in the 260z. Don't know about them in the Webers, but they do indeed get used and work well.
Rick-
Some years ago I contacted Carroll Shelby (who doesn’t know me from Adam) about the fine points of setting up Webers. This part of the reply applies to your question:
Carroll Shelby sent your question to the Shelby American Automobile Club
and I contacted THE expert in the Webers for Fords field; this is his
answer:
Howard C. Pardee
<snip>
Set the floats exactly to factory specifications, and install a Grose Jet in place of the Weber needle and seat. The stock needle and seat is not at all tolerant of pressure rises, and will leak easily. The D&G valve will handle up to about 6 lbs....cheap insurance. They'll cost about $30. These are sold by D & G Valve Co. in Massachusetts; they advertise in Hemmings (no, I'm sorry I do not have their phone number). Fuel pressure is very critical, and should be strictly regulated not to exceed 3 lbs.
<snip>
I have never been able to locate a Grose Jet though—Ron, do you have a source?and I contacted THE expert in the Webers for Fords field; this is his
answer:
Howard C. Pardee
<snip>
Set the floats exactly to factory specifications, and install a Grose Jet in place of the Weber needle and seat. The stock needle and seat is not at all tolerant of pressure rises, and will leak easily. The D&G valve will handle up to about 6 lbs....cheap insurance. They'll cost about $30. These are sold by D & G Valve Co. in Massachusetts; they advertise in Hemmings (no, I'm sorry I do not have their phone number). Fuel pressure is very critical, and should be strictly regulated not to exceed 3 lbs.
<snip>
Thanks for responses. I welcome others. This can benefit many of us. I have been told that the individial who was responsible for their design had died hence the company closed. However I have no hard firm evidence of this and have seen them being sold for SU carbs (maybe knockoffs). There also is a "Glass Ball" design being used in the VW drag race crowd that supposedly will tolerate 6 lbs of fuel pressure. I am on the hunt!
Let us know what you turn up.
John
John
