Fuel. Priming

[Martin Benade]

Unless you add a valve to it as I’d stated. A common part at your FLAPS.

[Ron LaDow]

Spent a lot of time and (Alan's) dyno money; here's the best we found:
https://www.912bbs.org/forum/ams/ladies ... ngines.10/
Depending on how much you value originality, Al Z's FI will probably give you instant starts; didn't include that.

[Harlan Halsey]

Hi All.
Has this been done , or even feasible ? We all know how quickly our Carb Float Chambers dry up / evaporate. Wondered if it is both safe or possible to adapt a Spare Gas Tank Lid fitted with a pressure regulator ( Set at 3 PSI ) and a Tire Valve fitted to the inlet side. This would then easily connect with one of those electrical tire pumps available. So, pumping direct through the gas tank. , Pet Cock through to the Carbs.
Just a thought, am I mad? Didn't know if the Petcock would be up to it ?
Just thinking
Jay

I think pressurizing the fuel system to fill the float bowls is a good idea. Porsche did it with the Carreras putting the electric fuel pump in the front of the car. Rather than modify the cap I'd pressurize the vent tube. 3 psi on the vent tube for about 20 seconds should do it. Perhaps one of those battery powered tire pumps could be modified to 3 psi.

[Marcus van Bers]

I've installed electric fuel pumps (2-4psi) on two other carb vehicles I've had for the very purpose of priming them after sitting for awhile. In both cases you can hear a change in the noise from the pump when it has filled the bowls. Can take anywhere from a few seconds (sitting for a few days) to half a minute (first start after sitting all winter). When I hear that change I turn the ignition and they start right away. You can wire them so they run continuously (if inoperative mechanical pump) or install a switch to turn them off once the car has started and the mechanical pump takes over.

[John Clarke]

That's great Marcus. If You want to go down that route. And as I posted earlier, that Topic has been covered to death ! We know about installing all different kinds and makes of pumps into the 356 fuel system. But, this idea Is A Completely different approach to achieve the same result without having to install a secondary fuel pump. You can leave the fuel system stock. You Simply shut an Isolator Valve / Tap in the Gas Tank Vent Pipe, Fit the Spare Modified Fuel Tank Cap with pressure regulator Set At 3 PSI Installed with a Simple Tire Valve fitted , and pressurize the fuel system with one of the many Electric Tire Pumps available . Many thanks for the.many different pump suggestions, but this is a Different Approach !
Kind Regards Jay

[Marcus van Bers]

That's great Marcus. If You want to go down that route. And as I posted earlier, that Topic has been covered to death ! We know about installing all different kinds and makes of pumps into the 356 fuel system. But, this idea Is A Completely different approach to achieve the same result without having to install a secondary fuel pump. You can leave the fuel system stock. You Simply shut an Isolator Valve / Tap in the Gas Tank Vent Pipe, Fit the Spare Modified Fuel Tank Cap with pressure regulator Set At 3 PSI Installed with a Simple Tire Valve fitted , and pressurize the fuel system with one of the many Electric Tire Pumps available . Many thanks for the.many different pump suggestions, but this is a Different Approach !
Kind Regards Jay

Ok, I get it now. Very interesting idea.

[Vincent Canzanese III]

Instead of an Electric Tire Pump with a regulator, you can feed the regulator with the spare tire as your air pressure source somehow. VW used the spare tire on later model Beetles to pressurize the washer fluid system.

[Wes Bender]

Too bad Rube Goldberg didn't own a 356.

[David Jones]

One could spend a lot of time and money improving things on a 356 that gains one absolutely nothing. Some obviously do.

[Dave Erickson]

It seems like either a poppet or a solenoid valve on the breather tube might solve or at least help the evaporation problem. That and going to the early tops for Solexes with the smaller diameter breather.

[John Clarke]

Hi David. Love Your humour.
Explain Please ?
And Dave E, We can't change modern fuel. It's a Simple Principle Just need to adapt to modern fuel and force feed the Fuel to the Carbs Float Chamber, to hopefully Fire Up. !
The 'Principle' in my idea is to simply deliver ( momentarily) the modern gas directly to the float chamber. Ready to hopefully ignite. I do take on board all the good advice ref priming the Oil System First..
Cheers Jay

[David Jones]

Jay, I am all for innovation and improvement. I'm on my 4th wife! I think long and hard about any changes I decide to make. There has to be either a safety, performance, reliability or some kind of justifiable payback and in a reasonable time frame. I'm too old to have to wait more than a few weeks to see the payback.

[Wes Bender]

Jay, your idea can certainly be made to work, but isn't it simpler to just push the fuel momentarily and directly with a small electric pump? Many of us are doing that now. Some use the rubber bulb method which works quite well too.

If I wanted to, I could put a small adapter between a carburetor and manifold, pull a vacuum from it and store it in a tank, use a solenoid operated valve to send that vacuum to power a small set of bellows to generate 3 psi of air pressure, plumb that to the fuel tank, regulate the tank vent with another solenoid operated valve and then use an automatic timing device to allow the bellows-driven air pump operate for a specific amount of time when the ignition is first turned on. Obviously, additional steps or devices could be added to overcome any other issues, but you get the idea....

You're way ahead of me David. I'm still on my first.

[Harlan Halsey]

No Wes and David the air pressure idea, which is not new to me, can be about as simple as it gets with the availability of modern battery powered air pumps. Open the hood, attach the pump/regulator to the vent line, pump for a minute, detach, close the hood and start the car. (I already have a 912 and a 356A with added electric pumps. They work well but they were not that easy to plumb.)

[Vic Skirmants]

If I wanted to, I could put a small adapter between a carburetor and manifold, pull a vacuum from it and store it in a tank, use a solenoid operated valve to send that vacuum to power a small set of bellows to generate 3 psi of air pressure, plumb that to the fuel tank, regulate the tank vent with another solenoid operated valve and then use an automatic timing device to allow the bellows-driven air pump operate for a specific amount of time when the ignition is first turned on. Obviously, additional steps or devices could be added to overcome any other issues, but you get the idea...."

Wes; I know you're kidding; right?