15 replies to this topic

[Jackmancer]

I was reading 'Rolt and Bira' by Hay Neville, and on one paragraph it said (about the ERA car):

"The Wilson pre-selector gearbox was heavy but it was reliable and to some extent enabled the driver to keep both hands on the wheel - when he was not desperately pumping up the fuel pressure."

 

Did cars back then have a manual pump to increase the fuel pressure? I'm totally unaware of this and would like to learn more. Googling is a tad difficult.

[Allan Lupton]

Air-pressurised fuel tanks were of course a hang-over from the days of riding mechanics but, even so, the "desperately pumping up the fuel pressure" is a pessimist's view of the matter. Except when the tank is nearly full, the pressure does not have to be pumped up very often and could be done on any straight bit of track.

 

 

PS I think you'll find that author was Neville Hay, not Hay Neville

Edited by Allan Lupton, 25 September 2017 - 07:40.

[GMACKIE]

A common method of delivering fuel was to pressurize the [sealed] fuel tank - normally around 2 psi.

 

The hand pump provide the pressure,if the mechanical pump did not.

[Jackmancer]

Cool, thank you. I didn't realise this.

 

So they looked like this? 

[GMACKIE]

Actually, when the tank was nearly full the hand pump would be be need more often, but not for as long. As the fuel level went down, the pump would be needed less often, but for a longer time. This is assuming the mechanical air pump [if fitted] is not working.

[Lee Nicolle]

Pressurising fuel tanks was a fairly common thing on old racecars. In hindsight it does seem weird as there is electric pumps and mechanical pumps that have been around for the best part of a century. 

I can remember seeing Speedway midget and TQ drivers madly pumping in the 60s. Usually feeding SU or similar smooth bore carbs. They seldom ever had any engine problems though I do know of a few prangs happening while doing so.

AND not many years later a chap I know simply used a factory mechanical fuel pump to pressurise the tank. And that style of pump had been around for decades before. And he was feeding a supercharged Holden 6 with triple 2" SUs on methanol. A fairly large volume of fuel required. From memory 10 or 15sec on the starter would build enough pressure to start it. Though being methanol it was generally started cold with a spray of petrol to the intake.

I know of some midgets by that time were using a similar deal. 

The only draw back is if a tank or line ruptures you have fuel everywhere wheras with a pump the engine stops and so does the pump. And I know that has happened.

I have seen clips of [I think] prewar racers pumping up the pressure. Some of the Jay Leno collection use the system and have manual pumps to pressurise for initial start.

[Charlieman]

Bikes too. Gravity is sometimes not enough.

[BRG]

Manually applied pressure has a long and distinguished history.  As late as 1963, the brand-new Hillman Imp Mk1 had a windscreen washer bottle (or rather a pouch) that needed pumping up to work, as well as a pneumatic throttle linkage that needed regular pumping with the foot if you were not to subside gradually to a graceful standstill.

Edited by BRG, 25 September 2017 - 14:49.

[Vitesse2]

You might find this video informative, Jackmancer:

 

[Peter Morley]

GP Bugattis have a hand pump to pressurise the tank when starting.

The engine has a mechanical air pump that takes over when it is running.

If the mechanical pump fails then the driver or mechanic has to pump manually occasionally while it is running.

 

Part of the reason could be that they were running methanol which requires huge volumes and it might have been difficult to find a suction pump that delivered enough volume.

[f1steveuk]

Had to do it often in the cars at the museum. Pressurise the tank to get fuel through, then a vac pump or similar system kept the pressure up. I was told by some of our older visitors that some drivers would continue to pump in the hope that more fuel would be forced through, and they would go quicker!

 

Of course, when I drove the 1904 Grand Prix Mercedes, pump air into the tank. Open the valve. Flood the carb. Swing the handle, and once running the engine pressurised the tank, but I still had to pump oil manually!!!

Edited by f1steveuk, 26 September 2017 - 14:16.

[Michael Ferner]

Any excuse to post a Picture of a Miller...

Typical position of the fuel pump on a Speedway or dirt track car before WW2.

[Ralf Pickel]

Also - don´t forget that many racecars did not have any electrical circuit.

Running on mag ignition you do not need a battery or any charging device, so no current for a pump !

Of course, they did not have electric starters, either. Or lamps, turn signals, heated steering wheels...

 

Ralf

Edited by Ralf Pickel, 26 September 2017 - 14:26.

[Jackmancer]

You might find this video informative, Jackmancer:

 

 

that's terrific, thank you!

[Roger Clark]

In 1954, the Mercedes W196 had a manual fuel pump that had to be used to ensure that sufficient fuel reached the fuel injection unit when the engine was started. The drivers would often forget this and a mechanic would reach into the cockpit to operate the pump- a difficult procedure with the streamlined body. In 1955, an electric pum was fitted.

[Lee Nicolle]

Also - don´t forget that many racecars did not have any electrical circuit.

Running on mag ignition you do not need a battery or any charging device, so no current for a pump !

Of course, they did not have electric starters, either. Or lamps, turn signals, heated steering wheels...

 

Ralf

Modern Sprintcars and Midgets still work on that principle. Mechanical injection pump and a magneto. 

A few have dabbled with a battery and MSD style ignition at times though. Those magnetos put  lot of load into the drive gear on the cam.