Fords Inherent Bad Design

[68 Ford Stepside]

Ford's design of attaching the intake manifold to the exhaust manifold on the 240 & 300 engine does not work well down here in the South. It gets hot down here & the winters are usually mild. I've had my share of hot start problems on the flareside, caused directly by excessive heat on the carb. I installed a 1/2" phenolic spacer between the carb & manifold which helped a little. I lowered the float level 3/16" which helped a little. I installed a 1/8" plate between the carb & exhaust runner which seems to have cleared up the problem for now. It will be super hot again next year, but I have plans to nip this problem in the bud once & for all over the winter months.

I am not a design engineer, but I know how to fabricate what I want. See attached photo for my version of a heat diversion plate I plan to fabricate & install between the carb & manifold. I will still use the phenolic spacer on top of my plate. I will have to use longer studs which isn't a problem. I am confident that this upgrade will keep the carb from superheating & boiling the gas over.

My truck starts instantly when cold & runs down the road flawlessly, but shut it off hot, walk away for ten minutes & try to start it back up. It's not that hot today so the truck hasn't been a problem. Have A Great Ford Day!

[crazyhorse]

Mr Stepside, Good luck with that.

I had a 68 with a 240 six cyclinder and it had the same problem.
Let us know .

[knightfire83]

Aluminum transfers heat better than most metals though, that's why they use it in heat sinks.
I would think a plate made of aluminum would soak up even more heat from the (I assume) exhaust manifold under the intake.

You can buy Phenolic Sheet material of various thicknesses and spec. on e-bay which would be an excellent candidate for your project (and easier to work with.)
http://www.ebay.com/sch/i.html?_sacat=0 ... olic+Sheet

Good idea,

[68 Ford Stepside]

While I agree aluminum will soak up more heat, it will also dissapate heat faster than other metals. The phenolic material is good stuff, but I don't want to completely remove all the heat from the carb. If I were to do that, more than likely I would end up with the carb icing during cold weather. It's a fine line & will take some experimenting to make it work during hot & cold weather. That's the great thing about electronic fuel injection, it removes the guess work of figureing in climate when building a fuel system that may be in Alaska today & Florida tomorrow. Have A Great Ford Day!

[68 Ford Stepside]

It was eighty degrees here yesterday. I drove the truck over a hundred miles, stopping,waiting & cranking with absolutely zero problems. I think I'm getting closer to finding that fine line I was talking about. Today it's sixty two outside with twenty five mile per hour winds. I don't like season changes. Not if, but when I solve this hot start problem, I will be posting a detailed report of how to fix it for those frustrated souls that are having this problem. Have A Great Ford day!

[68 Ford Stepside]

30 mph wind today & cool. Don't think I'll be having any hot start problems for a while. Probably won't see any 95 degree days until next spring into summer. I'll fab my heat deflection plate this winter & be ready to start experimenting next summer. Last week I cut a 1/8" thick piece of aluminum plate & placed it over the exhaust runner right between the carb & valve cover. It has worked well during the last hot days we had. It was thirty six here last night, but it has to be at least 32 to determine if I'm going to have any carb icing problems.I am dedicated to eventually eliminating any hot start problems or icing from my carb. I might not have a lot of money, but I have an enormous amount of time to nip this (common six cylinder problem) in the bud, as Barney would say! Have A Great Ford Day!

[crazyhorse]

Mr Stepside, I like that "nip it in the bud".
Good luck with the truck.

[ezernut9mm]

how about a clifford and some headers. should do the trick.

[68 Ford Stepside]

Clifford is too rich for my blood, I 'll just fix it the old fashion way.

[ScottT80]

I have similar issues with my 390 truck. Having to let it cool a few minutes is a nuisance in the summer. Let us know what you end up with.

[ezernut9mm]

I have similar issues with my 390 truck. Having to let it cool a few minutes is a nuisance in the summer. Let us know what you end up with.

a few minutes? you lucky dog. i had to let mine cool for about two hours in 90* heat in the summer.

[jzjames]

when the engine will be hot and the gas in the carb just about boiling, try this:
just turn the key without touching the gas pedal with your foot. It might just fire right up.

[68 Ford Stepside]

I have tried your little trick before without success. At least in my case, the one & only way it will start is by holding the footfeet all the way to the floor which has always been the starting procedure for a gas rich engine. I only have problems on 90 degree days. Have a great Ford day!

[ScottT80]

Normally mine will start right up after about 15 minutes or so. I have to leave it running when I get gas in the summer or run to the dump.

[mjhaltom]

Clip a couple of clothespins on the fuel line. Redneck heat sink! SOund ridiculous but seems every old beater I buy has those there.