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Thanks for the info.
I have a 70 GTV which I am trying to put on the road after 20 years of storage.
I removed the Fispa filter which I was gonna replace with a 'modern' cheapo fuel filter. However, after I opened up the Fispa I noticed a diaphragm and got to thinking that it served to more than just clean the fuel. So I consulted this forum and concluded that it was necessary to keep the Fispa in place. Is this correct or is there something more 'modern' used now?
Thanks for your help. James
 
The Fispa is best and easiest. The FRB 11 was used by both Ferrari and Alfa in front of Webers. You should replace the diaphragm and fuel bowl seal with modern fuel proof viton parts. They are available from "Partsource" owned by Geoff Ohland, and some other speciality Ferrari parts suppliers. The FRB 11 will damp out fuel pump pulses, and keep the pressure at a good-for-Weber 3 lbs.
 
For the FISPA fuel filter/pressure regulator, there is a set screw on the top, apparently for regulating the fuel pressure to the carburetors. Which way does one turn the set screw to decrease/increase the psi setting? I tested mine for fuel pressure yesterday, with the screw lined up with punched marks, and it measured 5 1/2 psi. I tried turning the screw, but could not discern a change.
Thanks in advance for your knowledge.
Jim Enloe
Iowa City
 
If the diaphragm is stiffened, or the spring weak, it will not change. Take it apart to check the diaphragm. Often the adjustment mechanism has rust inside. It should be clean. Somewhere on the BB, I posted a series of photos showing dis and re assembly. If you cannot find it, contact me by e-mail and I'll dig them out of my files. You may need to make a new spring. See photo's.<dademon@mindspring.com>
 

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I discovered a new leak on my Fispa regulator. It looks like it is coming from the inlet side of the unit near the fuel hose. On the second photo the fitting has a 90-degree bend and it looks like a metal disc in that fitting, it was loose and crooked in the fitting. I pushed it back in now it looks like the other side. I took the photos after I pushed the disc back. Could that be a source of a leak? What is the purpose of those plugs?
Auto part Automotive engine part Wheel
Auto part
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The plug was to cover the hole of the drilled passage. Drill bits dont like right angle turns.
GLUE the plug in with a fuel proof Epoxy.
 
Is that what was done at the factory, gluing the disc in a hole? I am thinking 2 part epoxy. Not sure it is fuel proof?
 
Factory had a tool that upset the dome of the steel plug, and upset a ring of the zinc body over the edge of the steel plug. Flattening the dome of the plug expanded the OD of the plug and the upset edge of alloy held it in place. Hard to duplicate as a DIY job. Those that leak I glue in. Google fuel proof epoxy or check what you have, several are listed as "fuel-resistant".
Auto supply store will have something.
 
Gordon, I may as well take it apart completely to clean and inspect while it is out? The consumable parts are still available at Alfa Stop UK. Is this an FRB11 or FB43? I don't see those markings on it. Also, pin vs no pin? I guess mine has a pin attached to the bottom of the diaphragm, based on the 1st photo.? The only part I didn't remove was the yellowed plastic part in the last photo. What does the pin push on? Did I read somewhere else about a ball bearing? All I see is the small spring and the yellow plastic thing. Is there somewhere that shows a cross-section drawing and operation of this unit? I put both diaphragm surfaces on an emery cloth on a flat plate and gave a quick polish. The outlet brass colored pipe has the slightest bit of play (I can barely feel it move) is there any way to improve that, or more epoxy? Everything was clean inside and the diaphragm is still supple.
Disc brake Auto part Rotor Brake Vehicle brake
Auto part Automotive engine timing part Automotive engine part Clutch
Auto part Automotive engine part Rotor Disc brake Machine
Auto part Clutch Wheel Automotive engine part
 
Pinned FRB11. Fuel proof diaphragm and bowl seal are available in the USA from Partsource in Camden, Maine. Ferrari uses the identical FRB 11's on older Ferrari's with Webers. If you replace diaphragm, you will need to re-adjust to about 3# fuel pressure running on your car using an accurate fuel pressure gauge.
 
My diaphragm is the least of my worries and the bowl seal is soft enough as well. I need a ball bearing, mine is gone hasn't been one in there for over 35 years! Does anyone know the size? I wouldn't mind having another yellow plastic spring and ball keeper. Also the main body that has the 2 hose outlets would be on my wish list as well. I wonder how this will change the way my car runs when I fix all this?
 
Both diaphragm AND bowl seal are the parts that will fail very quickly with todays fuel Brad. The FRB11 was made for gasoline, not todays fuel which will harden the diaphragm, alter adjustment and eventually crack as it hardens and leaks. same for the bowl seal. These components need to be replaced with fuel proof or Viton replacements for safety.
If originality is unimportant, just buy a new Filter King unit. These are manufactured for todays fuel, and will not lose adjustment or leak with age.
As FRB11's have not been manufactured in some time, the plastic spring and ball retainer is no longer available unless you have a junk unit to borrow salvaged parts.
I've rebuilt / restored these for concourse use for years. I DO NOT sell parts as my customers get them in my rebuilds.
Here is a 1967 GT FRB11 almost ready for reassembly with new diaphragm and bowl seal in transit.
1630524

Here is the Filter King unit popular with racers.
1630525

Filter King makes several variations, this one is popular. All the Filter King units have better pressure adjustment range than restored FRB11's.
 
Ball diameter is .375, I was contemplating making ball spring retainers from aluminum. The earlier banjo FRB11’s were made from aluminum not from plastic from the ones I’ve taken apart. I would like to find a source for the springs though.
 
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