Vapor lock and fuel boiling

[x33rs]

I see you're in Kentucky? When I lived in Ohio I remember 15-20 years ago there was a big stink about Kentucky switching to reformulated fuel. May have been further back, my memory is fuzzy. Anyway, not sure if that ever happened but you guys are also starting to get into your winter season, and I believe by now the fuel has switched over to the winter blend. So if you're still getting some warm days, that stuff will vapor lock in a heart beat.

I always hated that in Ohio (they did the same thing) because if you have any of those warm days that so often happen in the fall and spring out there, that winter blend fuel is absolutely horrible for vapor lock. It would always bite me in the spring when you get a few odd warm days in March with temps in the 70's, and Ohio wouldn't switch to summer blend until April or May.

[x33rs]

If you have non alcohol fuel that would certainly help. Seems more and more of those are popping up.

Where I'm located, we have one station that carries it, and it was just built last year. The problem though is that it's only available in 87 octane and I can't run that low of octane in our stuff.

I'm not sure what is out there for additives that might help or if there is anything that actually works. The only thing I add to my fuel is a pinch of 2 cycle oil with TCW3 only for some lubricity and cleaning purposes, since the lead is gone. 1 ounce per 5 gallons of gas.

[JKZ27]

The Pure-Gas website shows Casey's General store near Central city sells 91 octane. Might be worth a look.

https://www.pure-gas.org/index.jsp?stateprov=KY

[big gear head]

Originally Posted by JKZ27

The Pure-Gas website shows Casey's General store near Central city sells 91 octane. Might be worth a look.

https://www.pure-gas.org/index.jsp?stateprov=KY

That is exactly what I'm running in my car and it runs good on that. I have no more problems, but these other guys don't live in the same town, so they can't get their gas there. I've never heard of the pure gas web sight. I'll have to check it out.

[1967 4K]

I live in central Ky. and run Shell or BP high test in my L78 engine and have never had any issues as being discussed here.
Richard

[Steve Shauger]

I drive my cars L78, Z28, L72 regularly spring -summer and fall. Most of the time pump gas and have never had an issue. Only starting issue I had was heat soaked starter solenoids in summer and changed them out to high temp years ago.

[JKZ27]

That site has a handy map that helped me find E-free gas near me, mainly for my small engines and ATV stuff. I have been using 93 octane, 10%Ethanol in all my Camaros without issue. My 69 and 79 use stock return style pumps and my 68 is return style EFI, FWIW.

[x33rs]

Playing with resizing some pictures. Don't know if this will work or not. But anyway, this is my wife's Z that she daily drives. I've made no attempt to move or insulate any of the factory lines.
I do run a 1/4" thick base plate gasket to help with heat (probably can't see in the picture), and I still have the heat cross over open so the divorce choke works, but I haven't found the need for any type of heat shield under the carb. I was open to that option if a problem existed, but it's driven fine for the last 2 years without.
I was a little concerned with vapor lock since this is our only daily driver that uses a dead head fuel system. Everything else here is a return style. But it's proved to be a trouble free driver. It's a true 11:1 compression and runs fantastic on the 91 pump we have here.