Gas cap venting?

[alfabits]

This is what I ended up doing for the moment. I am making a screw-in one way valve to indct into the cap center hole.

George

[Gordon Raymond]

Looks good George! If you blow in the middle hole, does the air come out the outside ones? If so you should be fine. I wouldn't worry about the pin valve, unless you like to overfill. As I mentioned, it really does not seal 100% anyway. However, as was mentioned, since I OFTEN corner at 1 G +, ( ) I'm glad to have the leaky valve on my "Jewel"! Gordon Raymond

[AlfaDuc]

Gordon,
Slightly off topic, but at least related ... Does your '65 Veloce use the mechanical fuel pump (bolted to the lower corner of the timing cover, beneath the distributor) or does it have the Facet electrical pump back near the fuel tank? I know the Giulietta Veloces used electrical pumps, but my two '65 Veloces have the mechanical pump. And the Giulia parts book seems to indicate that the mechanical pump is correct. Just curious, because I'd like to use the most correct pump now that the restoration has started to creep into gear on Veloce #2.
Thanks, Jim

[Gordon Raymond]

Hi Jim.
Correct for your installation is the mechanical pump driven off a lobe on the distributor shaft. My car is a one-off, in that it is an Ausca spider with GTA running gear. As such, when raced, it used the pair of Bendex electric pumps, in back. These were always overkill, as the only need for the pair was when it was REALLY HOT, and vapor lock might be a problem. This never happened, so when one Bendex finally died, I went to the single Facet. That also works perfectly. The parts book shows the later cars all with the Fispa mechanical pump. As once a race car, the electrical pump has the advantage of STOPPING fuel flow at the flick of a switch, whereas the mechanical continues to pump as long as the engine runs. Also interesting is that in my particular car, the mounts for the electric pump were in place when I purchased the car. You might check under some other '65's and see if they came with the bracket back by the tank as well. Does this help? Gordon Raymond

[alfabits]

Quote:

Originally Posted by Gordon Raymond Looks good George! If you blow in the middle hole, does the air come out the outside ones? Gordon Raymond

[Andrew]

My Giulia Super years ago tried to collapse the gas tank from the vacuum created from an apparent lack of vent. I drilled a small hole in the cap (so it would be oriented upwards when installed) and have had no further troubles. If the cap was already vented somehow, it wasn't working.

Many caps fit so poorly, or have worn out seals, that they self-vent.

Andrew

[AlfaDuc]

Quote:

Originally Posted by Gordon Raymond Hi Jim. Correct for your installation is the mechanical pump driven off a lobe on the distributor shaft. You might check under some other '65's and see if they came with the bracket back by the tank as well. Does this help? Gordon Raymond

[B24Spider]

Andrew, that may be the second time that happened to your Super. If my memory serves me well (keep in mind we're talking some 20+ years ago), shortly after I bought the car from Russ Potts' estate, I ran out of fuel late one night NB above the Golden Gate Bridge, just before the tunnel. After hitching down to Suasalito to find a gas station with a gas can, the tank would take barely any fuel. Further inspection the next day left me flabbergasted. Even though I realize they aren't constructed to hold negative pressure, it's amazing the vacume a tiny mechanical pump can draw. I think I have a (poor) photo of the collapsed tank somewhere. I can't remember where I got another tank, as well as a vented cap, but it wasn't easy, even then. Boy, was I p!$&@%-off.

[Andrew]

Thanks Steve.
Gordon, your AUSCA Spider has the hood prop on the passenger's side. My Giulietta has it on the driver's. Was that peculiar to your car, or were all Giulias that way? Thanks

Andrew

[Gordon Raymond]

Hi Andrew,
Alfa probably changed the hood prop with the Giulia's to confuse people years after the fact. I too have noticed the change and have not studied the transitional cars closely enough to tell exactly when that hood prop moved from one side to the other. As my car is a late Giulia, the early ones may hold the clue. I do not know if any of the flat hoods with center trim had the prop on the hood and cars left. Interesting question. More interesting, why?
Gordon Raymond

[Andrew]

I thought it might be a clearance issue for the 1600 type air canister, which is not an issue on your car. Seems a stretch though.

Andrew

[Gordon Raymond]

Hi Andrew,
All the stock Veloce 1600's have the air cleaner canister low enough that the prop wouldn't hit with a closed hood. An interesting idea though.
Gordon Raymond