Greetings, I have a 1941 olds business couple, mostly original or updated as close to original as we could get. Anyways, I noticed recently when the car sits in hot environment (parades, sitting in 1 spot for awhile) the fuel in the bowl starts bubbling (boiling) it looks like (I just noticed this when I opened the hood recently when I got home from a cruise). On this particular car the in line gl*** bowl fuel filter sits pretty close to the exhaust manifold, causing lots of heat. Any thoughts on creating a heat shield/insulator type set up to keep the heat away from the gl*** bowl and hopefully keep my car running better in hot environments. I’ve attached a photo for reference. Any thoughts or ideas are welcome. I know some people say bubbling could come from faulty fuel pump but the fuel pump is new and never had any issues.
This is common these days because the fuel they sell now is so volatile. It doesn't matter in a sealed fuel injection system but it does in old carburetted cars. You could cut a piece of aluminum to bolt between the carb and manifold, maybe even add a phenolic spacer for insulation. Aluminum is good for reflecting and dispersing heat. Make it big enough to shield the carb float bowl and fuel filter. Another common cure if your car suffers from vapor lock, is to add some kerosene or diesel to the gas to raise the boiling point. I gallon to 10 of gas is usually enough to prevent vapor lock and old low compression engines run better on this mix than on hi test. Another old cure is to wrap aluminum foil loosely around the fuel line to insulate and reflect away heat.
I drive an OT 442 that has 11:1's under aluminum heads and there is a lot of heat being dissipated under the hood. The factory ran the fuel line up the front of the block from the fuel pump to the carb which just wasn't going to cut it. I went to an in-tank pump/return line and re-routed the delivery line up the firewall and reversed the dual feed on the carb . A lot cooler fuel as a result. And I added a phenolic spacer under the carb. I have no issues now. You're filter is sitting on the upper rack of a toaster oven. Maybe you can re-route the line from the pump so you can get the filter to a cooler spot or as mentioned add a shield to block the heat. Nothing worse than a hot blooded Olds.
You are experiencing vapor lock.Wrap aluminum foil around the gl*** fuel bowl. Then wrap that in a piece of leather as an insulator. High quality exhaust wrap may also work. Plus you could make an insulated metal box to fit around the gl*** fuel bowel. Here's a photo showing the thin aluminum metal bos that slips over the fuel regulator. Box is lined with cardboard and fibergl*** cloth sandwiched between aluminum A/C duct tape. I would have lined it with exhaust wrap if I had some. I did wrap the regulator with aluminum foil. Box just slips over the regulator. Check underhood temp with an infrared temp gun and you will be amazed how hot it gets. This article tells how ethanol treated gasolene is more prone to vapor lock than regular gasolene. https://www.grabner-instruments.com...ssure vl ratio of gasolineethanol blends.pdf
I used an aluminum Walmart cookie sheet to build a heat shield between the carb and manifold. No vapor lock problems with 5 psi fuel pressure.
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