Goodbye to Percolation/Vapor Lock & Heat Soak
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Goodbye to Percolation/Vapor Lock & Heat Soak
Like many, I’ve experienced issues with both hard start after a good drive and with what appeared to be an empty primary bowl on the day’s first start. In hindsight I attribute the entire mess to a painful lack of planning on my part. The rubber fuel line and the metal fuel filter were routed in such a way that both touched the engine or were in close proximity—headers didn’t help.
How did I proceed? Since altering the routing was problematic, I decided to reposition the fuel filter to just above the pump and to use a DEI Fire Sleeve & Tape Kit (010472) 5/8" (0.625) x 3'. (Two sections were used, one from carb to filter, one from filter to pump.)
According to product info, the sleeve protects from direct heat up to 500 degrees and withstands 2000 degrees of intermittent heat. The kit includes a 16-inch length of Fire Tape, which is a non-adhesive silicone rubber tape that is self-bonding, self-curing, and forms a permanent watertight barrier. It also finishes off the ends to protect against radiant heat entering the ends of the sleeve.
To further aide in eliminating the issue, my intention is to use ethanol-free fuel in the future.
Note: On my application a spacer or thicker carb gasket wasn’t an option as hood room is a concern.
As can be seen below, the sleeve is bulky (but pliable) and slips nicely over a 3/8” fuel hose.The tape is remarkably thin but holds, stretches and conforms very well. I used four four-inch segments, one at the carb, one on each side of the filter and one at the pump.
To gauge how successful the repositioning+sleeving was, I used an infrared thermometer on the fuel filter both before and after the swap. Before the swap with a 30-minute heat soak, the reading was 185+. After, 120+.
Before, with a spirited drive (city & highway), the car exhibited hard start with some cranking and pedal. After the swap, the car fired immediately.
First start of the day? Before the swap, excessive cranking and pedal. After, a touch of pedal to set the choke and the engine fired straightaway. All in all impressive.
For about $32 to include a Wix 33033 fuel filter (O’Reilly’s) and the DEI kit (ebay), I’m well satisfied.
Update: All has continued to go well with some temps in the upper 90s and heat indexes of a 100+.
JamesC
How did I proceed? Since altering the routing was problematic, I decided to reposition the fuel filter to just above the pump and to use a DEI Fire Sleeve & Tape Kit (010472) 5/8" (0.625) x 3'. (Two sections were used, one from carb to filter, one from filter to pump.)
According to product info, the sleeve protects from direct heat up to 500 degrees and withstands 2000 degrees of intermittent heat. The kit includes a 16-inch length of Fire Tape, which is a non-adhesive silicone rubber tape that is self-bonding, self-curing, and forms a permanent watertight barrier. It also finishes off the ends to protect against radiant heat entering the ends of the sleeve.
To further aide in eliminating the issue, my intention is to use ethanol-free fuel in the future.
Note: On my application a spacer or thicker carb gasket wasn’t an option as hood room is a concern.
As can be seen below, the sleeve is bulky (but pliable) and slips nicely over a 3/8” fuel hose.The tape is remarkably thin but holds, stretches and conforms very well. I used four four-inch segments, one at the carb, one on each side of the filter and one at the pump.
To gauge how successful the repositioning+sleeving was, I used an infrared thermometer on the fuel filter both before and after the swap. Before the swap with a 30-minute heat soak, the reading was 185+. After, 120+.
Before, with a spirited drive (city & highway), the car exhibited hard start with some cranking and pedal. After the swap, the car fired immediately.
First start of the day? Before the swap, excessive cranking and pedal. After, a touch of pedal to set the choke and the engine fired straightaway. All in all impressive.
For about $32 to include a Wix 33033 fuel filter (O’Reilly’s) and the DEI kit (ebay), I’m well satisfied.
Update: All has continued to go well with some temps in the upper 90s and heat indexes of a 100+.
JamesC
Last edited by JamesC; 08-30-2021 at 03:12 PM. Reason: Update
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NoEmissions84TA (08-21-2021)
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