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Vapourlock - It can leave you sitting

Published in Technical
Written by  04 October 2012
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While at Studefest in 2010 our 64 Cruiser stalled out and was really hard to start. Al Jordan and Bill Patterson were assisting me in trying to start the old girl by pouring some gas down the Carburetor and after some flooring of the gas pedal she finally started up. They both indicated that it was probably vapourlock but it was news to me as this was the first time it has happened in the Cruiser. I was able to keep it going and got to a gas station where I filled the tank and made it back to the hotel with no further problems.

What is Vapourlock? It’s when the fuel in your gas line is so hot that it turns into vapour due to its close proximity to the engine. You can’t run your car on vapour so this situation will leave you sitting on the side of the road scratching your head. The thinner ethanol based fuels we use now also increase the chances of vapourlock so this needs to be fixed if you want to use your car on these hot summer days. When back at home I inspected my fuel line and notice that I had installed it too close to the intake manifold and so I re-routed it away from the hot engine towards the water pump manifold. It’s closer to the fan and further away of the motor so this will help.

Some of the other things you can do:

Use only Non-Ethanol Gasoline – Some premium gases sold in Ontario are High Octane non-ethanol fuels. Although most of our Studebakers were designed to be used with regular gas, all regular gas in Ontario has Ethanol which should be avoided when possible. In Ontario, Shell, Cdn Tire & some Flying J locations sell 91 Octane Premium which has no ethanol and most gas stations in the US sell non-Ethanol Premium gasoline. Visit (Ethanol Free premium Coalition) and (Pure Gas) for the full story.

Insulate your Fuel Line – It comes from Tech Flex and it’s good for 950 degrees F. You install over the fuel line and put ties on it to properly secure it. This cover protects the fuel line from getting too hot and greatly helps in preventing vapourlock. For more info go to It’s available at for $10 or more depending on size and length.

Install an electric or 5 or 6 blade clutch fan to keep the engine cooler. The stock 4 blade doesn’t always cut it and if you have a V8 that has rust and corrosion in your water jackets, this tends to make the engine run hotter. When Bill Patterson took out a small coffee can of build-up rust and corrosion from the water jackets in the engine block when he was rebuilding my 289, I learned that this is a common occurrence in all V8 designed engines. If you look at the way the engine is installed. It points up at the front end and if the engine’s cooling  system isn’t flushed out regularly it tends to allow accumulation of rust and corrosion in the rear of the engine block water jackets.

Install an electric fuel pump – this will ensure you have a constant flow of fuel to the engine, it needs to be installed near the fuel tank and hooked up via an on/off toggle switch under the dash and used mainly for hot summer days when this situation usually happens. Under normal conditions you would leave it off and use the regular mechanical fuel pump. Remember to ensure it’s turned off whenever you stop the engine because it may cause your car to leak out fuel due to the much higher pressure in the fuel line.

You can also install an in-line fuel filter which has a return line to the Fuel Tank as Bob Easton did on his 1960 Lark Convertible. He had the same problem when he went to the Crossroads Zone Meet in Chilicothe, Ohio. He had no problems now driving from Welland to Brockville return during last year’s Studefest.

Final Diagnosis and repair: After breaking down again en-route to the Maple Leaf Tour I proceeded to replace the Intake manifold which saw the original having burnt paint on the middle  portion. I also found that the Heat Riser valve was sticking closed which was the real culprit in this situation. After I replaced the intake manifold, cleaning/resetting the carb and removed the heat riser valve the car has worked fine since and has seen no reoccurrence of this problem. Ethanol Gas is still a problem and I now only use Premium non ethanol gas in all of our vehicles.

Maintaining our Studebakers in these days of unleaded, ethanol based fuels and hot summers has always been a challenge but if you have stalled out under similar conditions then this could be your fix to having a lot more fun and less time being under the hood fixing your car on the side of the road.

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