Re: Anybody got the end all cure for vapor locking?

Posted by Highlander160 On 2022/1/11 10:18:56

I breezed over a lot of replies, and not surprised to see the old tried and true "fixes" and the everlasting search for the reasons. I have some questions. When it's vapor locked, have you ever taken the fuel line off to confirm it's actually blocked by excess vapor pressure? As to it happening "...inside the carb..." that's partially true or helpful. How's the needle and seat? If the answer is that it looks new or we just got a kit from so and so, where did it come from?

Let's talk about today's fuels. I'm near Motown and I think Michigan hot summers are probably on a par with Louisiana. High humidity from being surrounded by lakes, temps in the 90s, none of it uncommon or pleasant in a vintage car. However I can't recall a single real vapor lock situtation since the mid 90s. Our fuel today, despite the rapid evaporative nature, is superior to what was around in the good ol days. Way more energy in it, more "light ends" to the blends, and frankly fuel injection CAN NOT have fuel that vapor locks so put 2 and 2 together and come out with Whiskey Tango Foxtrot. Since even our regular is better adding 2 degrees to your ignition timing is a monster drivability improvement and will tend to drop coolant temp just a wee bit, maybe 5 degrees on average. Fuel isn't "late burning" in the exhaust manifold adding a bunch of unwanted heat in the worst possible place when you do that. New formulations are also less apt to lubricate sensitive little carb parts like power valves, check balls, and the ultimate culprit, the needle and seat. Once the needle valve gets stuck in the bore of the seat (due to heat) no gas gets into the bowl and we run home to "VAPOR LOCK" because it acts like it. It ain't.

Look up Daytona Carburetor (in FL obviously) and scope out their solution to "vapor lock" via their exclusive needle/seat. Not the old viton tip or all brass. We fought the same scenario on a fresh 34 in FL on a tour and that's exactly what it turned out to be. The Daytona needle and seat was the answer, and that was back in 2010. No issues since in over 1000 miles of summer driving that I was aware of. I only use Daytona Carb parts in my rebuilds.

Now if you have that already then just stamp me a blowhard and have the mods delete my reply, but that's been the final solution twice in the last several years for me. And for the record this is for everybody reviewing this if they suffer it now and then too. Have fun, here's a link:https://daytonaparts.com/daytona-carburetor-float-valve.html