Just got back from a mid-morning ride and it's got to be at least 95 deg. already. When I pulled in, I placed my hand on the hood and you could fry eggs on it, although the temp gauge read normal. I popped the hood to vent and I noticed the fuel bubbling in the see-thru plastic filter. Is this normal in hot climates? If it is, I'm not too observant then. Also, would steel-braided line help keep fuel temps down, on the principle that lighter colors reflect heat.

JR

Just because your temp gauge reads normal doesn't mean you can't have hot spots in the block. If the fuel is bubbling you may be on the verge of vapor lock. On many cars the fuel line is run excessively close to the block and vapor lock can result in a hot climate. Cars today with electric fuel pumps have essentially done away with vapor lock, but any car with a mechanical fuel pump can experience the phenomenon.

Braided fuel line or some other proper insulating material wrapped around the fuel line from the pump to the carb can certainly help.

Also, is there underhood insulation on the car? If not, you might consider that.

JR -

Your not alone in your bubbling fuel woes.

Here in Hawaii I have the same problem. After changing the fuel pump and all the rubber lines, still no change. I found that wrapping the line next to the block with reflective heat shield did help some. Also, running 87 octane also helps. My engine temp. is good - (190 - 200). An additional problem the hot fuel causes is engine run on after the key is turned off. I plan to continue trying different heat reducing tips. If anyone else has an idea, Im all ears.

jredding said:Also, would steel-braided line help keep fuel temps down, on the principle that lighter colors reflect heat. JR

lighter colors relect light and therefore heat whereas darker colors absorb light

the lighter color reflecting heat from light will only help if you drive with the hood up.

the posts above are right.. when I got my current 69 the PO had mounted the electric fuel pump on the block..

while I was test driving i got a vapor lock from boiling fuel.. try to run your fuel lines as far away from engine as possible..

for that matter keeping your heater hoses away from your exhaust manifold will help some.

make sure your breather/pcv setup is correct and make sure your egr is functioning if you have one.

the hood blanket is essential..

Guess I have a "What's wrong with this picture" scenario under my hood.

1) Fuel line right next to block and heater hoses.
2) Mechanical fuel pump.
3) No underhood insulation
4) 93 octane fuel

I will correct and report findings.

Thank you all,

JR

P.S. I was under the impression that hood insulation would hold even more heat in.

The hood insulation is more to protect the paint and fiberglass from the heat and warpage more than anything else.

Thanks, Boss. May be looking into a new hood in order to fit upcoming engine mods, certainly the time to get the insulation.

JR

jredding said: P.S. I was under the impression that hood insulation would hold even more heat in.

technically it will but your first post mentioned frying egg on hood..

its not bird eggs on your hood that you have to worry about..

but a hot engine compartment can help bake bird droppings on your paint and cause expansion cracks

The insulation will hold some heat, but will save the hood. It is a good thing.

Many of our cars have a return line to the tank from the fuel pump. By circulating fuel to the tank the fuel is cooled and kept circulating so it does not heat as much to begin with. If you have an electric pump you may consider a return system. If you have a return system, make sure it is working.

Braided Stainless steel lines hold in the heat, or so I was told by a fella who built a street rod for Bill Elliot. He said that the first thing his mechanic took off the car because it causes vapor lock. I've noticed that all the cars at events that I have gone to when it's hot, that vapor lock, have braided stainless steel lines. Also more Fords than Chevys because their fuel lines are really close to the headers. So for what its worth, I run braided S/S lines on my Vette and most of the engine is Cromed (except the block and the heads) runs around 200 on a 100 degree day and I've never vapor locked in the 15 years I've had it on there.