Re: Vapor lock in a Skylane... not possible!


Of course it's possible. On a hot day if the plane is flown and then
parked on the ramp with the cowling closed, the heat under the cowling
can be so intense that it can potentially vaporize the fuel in the fuel
lines forward of the firewall. If the engine is restarted shortly
afterwards it's possible to experience vapor lock. This problem will
be worse if higher vapor pressure fuel is used (such as winter blend
autogas).

The solution is surprisingly easy. During those short turn-around
always open the cowling immediately after the shutdown. That'll let
the heat escape and avoid the vapor lock.

Guy Byars wrote:

I have heard a lot of arguments about vapor lock, but I do not understand
how vapor lock could ever be a problem in a Cessna 182.

With the high wing configuration, the carberator will always have a positive
fuel pressure due to hydrostaic pressure. How can vapor lock *EVER* happen
in a Skylane? As an engineer, I don't see it happening.

Now, on the other hand, if you have a low wing airplane with a fuel pump,
then vapor lock is a very real problem.

But vapor lock in a high wing carberated engine.... not possible.

.

Relevant Pages

  • Re: Vapor lock in a Skylane... not possible!
    ... parked on the ramp with the cowling closed, ... can be so intense that it can potentially vaporize the fuel in the fuel ... afterwards it's possible to experience vapor lock. ... the heat escape and avoid the vapor lock. ...
    (rec.aviation.owning)
  • Re: 98 concorde starting problems
    ... apparently it is not "very hard to heat up all the gas in the tank by enough to get anywhere near enough vapor pressure to cause vapor lock." ... Please explain how the fuel in the tank is heated by engine heat in a non recirculating system. ... Vapor lock is more likely to occur on the suction side of the pump and is virtually non existent on the pressure side of the pump up too the point where there is a component problem such as a failing fuel pump. ...
    (rec.autos.makers.chrysler)
  • Re: 98 concorde starting problems
    ... > tank by enough to get anywhere near enough vapor pressure to ... >>> Please explain how the fuel in the tank is heated by engine heat ... > That equals a head start as far as the fuel system is concerned. ... >> but then vapor lock doesn't occur in the tank in occurs in the ...
    (rec.autos.makers.chrysler)
  • Re: 98 concorde starting problems
    ... before you commit to that Matt, you might want to familiarize yourself with the criteria set for monitoring EVAP pressures on any vehicle built to 1996 or later OBD2 standards, because fuel heating is a very major component used in the EVAP strategy. ... apparently it is not "very hard to heat up all the gas in the tank by enough to get anywhere near enough vapor pressure to cause vapor lock." ... Please explain how the fuel in the tank is heated by engine heat in a non recirculating system. ...
    (rec.autos.makers.chrysler)
  • Re: 98 concorde starting problems
    ... Yet farther down you admit to having no familiarity with LH cars. ... Vapor lock is more likely to occur on the suction side ... >> the pump up too the point where there is a component problem such ... >> as a failing fuel pump. ...
    (rec.autos.makers.chrysler)