> My TR6 has been plagued by vapor lock since the engine was rebuilt 3 years
> ago.
<snip>
> It seems the fuel boils out of the bowls and
> will not restart.
This is not what people normally call vapor lock ... how do you know this is
the problem ?
> although it did fade out a couple of times while idling in hot
> weather.
Did it blow black smoke at the same time ? If so, you're having a float
valve problem ... what is the outlet pressure on your fuel pump ? Have you
replaced the float valves with stock ones (NOT Grose jets) recently ? What
about the floats themselves ? They can sometimes fail such that they just
don't float when they get hot enough.
If not, I would suspect an ignition problem, perhaps a bad coil or condensor
that doesn't cut it at high temps.
> This year I am determined to fix the problem. My 2 options are
> heat shields and an engine oil cooler.
Heat shields might possibly help if your problem is percolation (fuel
boiling in the float bowls). However, even with a fairly severe case of
percolation, it should still be possible to start the engine, just takes
longer. Basically you hold the throttles wide open and crank until it sucks
all the over-rich mixture through and the bowls cool until the fuel no
longer boils. This should only take maybe 10 seconds or so.
> My question is: Has anyone had
> success in eliminating vapor lock by installing an oil cooler. I
> don't want
> to do this if it won't help.
Vapor lock is when the fuel boils between the pump and the tank ... the pump
will not move vapor very well and so fuel delivery stops. If adding an oil
cooler can reduce the amount of heat applied to the fuel line between the
pump and the tank, then it will help. Seems unlikely to me, though.
Fuel boiling between the pump and the carbs is much less of a problem, which
is why putting an electric fuel pump at the rear of the car (next to the
tank) is the usual solution.
Randall
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