Vapor Lock Parameters?
Vapor Lock Parameters?
(OP)
Hello,
I was wondering what anyone could share or direct me to system application parameters for a port injected fuel system with a stand alone fuel pump (not in tank). I am currently running a fuel injected four cylinder with a Bosch vane roller fuel pump and it works fine until my bulk fuel temperature reaches about 138°F and then the fuel pump appears to be vapor locking.
Does anyone have any ideas on how I can calculate or obtain a window of operation for fuel temperature to prevent vapor lock in my fuel system? The Reid vapor pressure of my gasoline is about 9.0 .
Any help would be appreciated. (I am not a fuel system engineer)
I was wondering what anyone could share or direct me to system application parameters for a port injected fuel system with a stand alone fuel pump (not in tank). I am currently running a fuel injected four cylinder with a Bosch vane roller fuel pump and it works fine until my bulk fuel temperature reaches about 138°F and then the fuel pump appears to be vapor locking.
Does anyone have any ideas on how I can calculate or obtain a window of operation for fuel temperature to prevent vapor lock in my fuel system? The Reid vapor pressure of my gasoline is about 9.0 .
Any help would be appreciated. (I am not a fuel system engineer)





RE: Vapor Lock Parameters?
http://pump.net/liquiddata/vaporpressgasolines.htm
It looks like a fuel with an RVP of 9 would have vapor pressure of 1 atm at about the temp you mentioned, so you may be correct.
So what can you do? Here is a partial list of IDEAS (no gaurantees):
1. Cool you fuel via some sort of heat exchanger
2. Run lower pressures (which will require larger injectors and/or recalibration, this suggestion is mainly if you are trying to run excessive pressures as some people have been known to do) - should reduce required pressure head for your pump, and also possible reduce heat addition from the pump to the fuel
3. Mount the pump lower - more available head
4. reduce pre-pump restrictions - same
5. Use a smaller pump - less circulation will mean less heat addition via the return line, and will also probably introduce less heat at the pump. Doublecheck you fueling requirements on this one. You could also take this to the extreme by going returnless.
RE: Vapor Lock Parameters?