[Healeys] Vapor lock--another solution

Michael Oritt michael.oritt at gmail.com
Tue May 11 14:17:25 MDT 2021

So much attention seems to be devoted to issues of vapor lock/heat soaking,
I thought I would post an absolutely foolproof--if a bit radical-- solution
to this pervasive problem.

The car in question is NOT my 1954 100 Le Mans but rather my first race
car--a 1622 MGA-powered Elva Courier equipped with two HS6 SU's.  On hot
days it was often impossible to get the car to restart once the engine got
hot--which often happens when, for example, there were delays on the
starting grid and it became necessary to shut down due to threatened
overheating OR during restarts after an all-in black flag etc.

In such situations when the engine was "heat soaked" no amount of cranking
would work until the engine cooled down and on a few occasions I actually
missed getting off the grid--quite frustrating to sit there watching the
race proceed without me.

The solution I came up with was to provide a simple positive way of getting
relatively cool air into the combustion chamber.  The intake manifold had a
balance tube in which there was a threaded. plugged port.  I inserted a
brass 90 degree ell into the port and ran a fuel-proof hose (1/2" ID) back
through the firewall to a brass two-way ball valve with a lever handle
which I mounted through the dashboard near the steering wheel so that the
handle was easily accessed simply by reaching under the dash.

When it came time to start/restart a hot engine I would crack the valve
open with one hand and push the start button with the other.  Invariably,
despite high ambient or engine temps the car would fire off immediately and
I would close the valve immediately as it almost seemed like the car had
received a straight injection of starting ether and my intention was to
replace the manual valve with a spring-loaded version that would
immediately close when released.

I'll admit this might be an extreme solution but if one lives in a very hot
high temp/humidity climate and is continually plagued by what we call vapor
lock or heat soaking (luckily not a problem from which my 100 suffers) it
is worth exploring.

Best--Michael Oritt
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