Aurelia on fire

Appia, Aprilia, Ardea, Artena, Astura, Augusta, Belna, Aurelia, Dilambda, Lambda and earlier
Sebastien

Aurelia on fire

Unread post by Sebastien »

Here a small story, that happened a few weeks ago, on a cold winter day: Enjoy!

Aurelia on fire – almost !

Yesterday I decided to start the Aurelia, for the first time since october. Weather was nice, but cold, and I thought it a good idea to drive the car before the next snowfall.

The Aurelia always starts as soon as fuel reaches the carb, which I find fascinating compared to the horror stories of Ferrari owners, where there is always something missing, or a cylinder not firing. But I disgress.

So I drove it out of the garage, and for a few kilometers. Then I stopped at a petrol station to check tire pressures, and all fluid levels. Pushing the dipstick back in (no oil needed), I noticed fuel drops from the fuel filter. I checked the connections of the fuel lines, everything was tight. Nothing I could do myself immediately. So I drove straight back another few kilometers to my trusty mechanic, where the fuel leak with running engine was watched with growing horror. The exhaust pipe is a few centimeters away, and the wire to the sparkplug ready to give the necessary spark !

In 15 minutes he took off the filter, found a leaking gasket between housing and glasbowl, temporarily fitted a rubber gasket cut to shape, and the leak was gone. The car is now safe again. We shall however change the gasket for an original spec cork gasket, to avoid having to check frequently the tightness of the rubber one.

This small story with a happy ending made me think :
1. ALWAYS have a fire extinguisher in your car – I take it frequently, but not always. And yesterday I did not take it with me. One extinguisher permanently fitted per car is the easiest way not to forget it, and cheaper than any fire!
2. Check your car thoroughly after the winter, when it has been standing a long time. Check it with a running engine, and after warming up. Gaskets dry out, levels drop, tyre pressure can be severely reduced.
3. Why is the fuel filter after the fuel pump on some Aurelias? this way it is under pressure, and the smallest leak can cause a fire. If the filter was before the pump, with a leak it would only suck in air, and the potential consequences would not be so severe. However a leak would be more difficult to find. Later Aurelia series had pumps with integrated fuel filters, and a direct fuel line from the pump to the carb. In my opinion the best solution.

What is your opinion on this incident ? Has it happened to you ? What do you do to avoid it ?
Brian Long

Re: Aurelia on fire

Unread post by Brian Long »

Sebastien,

Your story is interesting! I had a similar experience with my B12 but it didn't get to the 'on-fire' stage.
As you know, my car had long periods of inactivity whilst I was working in Malaysia. I came back to Melbourne one time to get it ready for a Castlemaine Rally. I always used to take the cover off the carburettor float chamber to fill it with petrol (and remove the spark plugs and spin it on the starter until it registered oil pressure. Also I used to take off the rocker box covers and squirt oil all over the valve gear). Whilst spinning it over, I noticed petrol spilling out of the petrol filter housing. It so transpired that the alloy die-casting had distorted and the glass filter housing cork gasket could not take up the gap. I think the alloy had succumbed to the tension exerted on it by the clamp which holds the bowl against the housing. Maybe it was too tight....Anyway, a straight edge revealed a couple of millimetres of distortion and the housing had to be discarded. Our Aurelias are nearly 50 years old and they, like us, may be weakening!!!!
My pump has the integral filter housing also. I ran the car for a long time after that without the filter; petrol is clean these days. However, I have now fitted a Flaminia combined filter-regulator although I am yet to set the pressure correctly and the Queensland/New South Wales Lancia Clubs' Wintersun Rally, 700km away in Orange, is only a week away!


P.S. Conversely, whenever I restarted the Beta sedan, which I had in Malaysia, after a period of inactivity, its carburettor would always leak petrol until the gaskets swelled up again.

Kind regards and happy motoring - once the warmer weather arrives.

Brian.
Geoff Goldberg

Re: Aurelia on fire

Unread post by Geoff Goldberg »

A different version of this kind of problem: the Aurelias (and Flaminias) carburetors get very hot when they sit after running. Sometimes, I have found the carbs on the B24 too hot to touch, as well as the Nardi air cleaner.

When they sit still after a good hot summer run, the fuel boils in the carbs, and having no where to go, comes out and percolates and is released into the butterflies - collecting a small but significant amount of gas. Three problems from that -

- the gas goes into the cylinders directly, making it very hard to do a hot start (say you pulled off the road on a summer day to get some gas or have an expresso.... and its hard to start up again)

- danger of a backfire and fuel igniting (happened to me years ago with a 3C Flaminia in the Arizona desert. Flames coming out of the engine bay...

- and lastly, the gas thins the oil in the crankcase.

In the Nardi kit on the B24 convertible, its even worse - as the spacers between the carbs and the manifold are reduced in thickness due to the lack of clearance.under the bonnet. Still, this problem probably exists for all Aurelias.

I've been told that American racers actually solved this by using wood spacers between the carb and the manifold, to lessen the heat transmittance.

Another fix is to take a fule return line back from the carbs to the gas tank. This allows the gas, when under pressure from boiling, to go somewhere else. Ideally, you'd take it off the feed at the carburetor, but until we find the ideal banjo fitting, we tee'd the fuel intake line and ran a second line off back to the fuel tank filler (which we removed, drilled and put a fitting on the top.

The "tee fitting" in the fuel line is for the moment some stock American one-way valve, with a 1 mm third connection. That way, only a little bit of the fuel is sent back to the gas tank. Its not pretty yet, but boy does it work.

It was 98 degrees here this weekend, and I'd pull off the road for 20-30 minutes, and get back into the car and it would start right up, docile and like it was a cold start. Absolutely amazing. And no contamination of the oil either.

Geoff
Florent

Re: Aurelia on fire

Unread post by Florent »

Geoff,

Thanks for the hint, I'll try it asap as I have troubles to re-start my engine when really hot, even with a 4mm Teflon spacer under my carburettor.

On the injection Flavias, Lancia used, on the return line, a banjo wich was closed with tin and then drilled (+/- 1mm) to get the correct pressure and quantity of fuel returning to the tank.

Regards

Florent
Geoff Goldberg

Re: Aurelia on fire

Unread post by Geoff Goldberg »

Was able to look at a Fulvia yesterday, and on that Lancia also put a return line from the fuel banjo fitting right back down to the fuel pump. And I just saw on a 124 Fiat, a line running from the front carb back to the fuel tank... I guess there is nothing new here, but it works just fine.

Geoff
Jean de BARSY

Re: Aurelia on fire

Unread post by Jean de BARSY »

Hi Sebastien,

Great story. I feel that driving "old cars" means a lot more than just using it. You need to understand the mechanical touch of the car, and project yourself back in time. Cold engines, cold starts, warming up of oil and water... All these things are "out of this world" for the younger ones among us who never knew this. "Old cars"... it's a state of mind!

The reason why the fuel filter is "badly" located in the engine compartment, is simply because in the 50's you could have really dirty fuel and the fuel filter was an absolute necessity. It was even so useful you had to get easy access to it to get the filter cleaned 'en route'!
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