Because there's more to the internet than hits alone, Biker_Bry
wrote:
Some of you were looking at the ins and outs of Liquid Injecting Propane.
I'm a Yank, so sory my measurments are in English.
The difficulties to overcome LPEFI are as follows...
1. Propane cannot hold a liquid state at underhood temps (207deg F)
= about 97 deg C. Actually, I doubt thet it gets that hot under the
hood, though there may be hot spots where the local surface
temperature reaches that. The cooling system on my car operates at
around 80 deg C (which doesn't appear to leave much margin).
In a common fuel rail system, where the fuel is continually cycling
back to the tank, then the problem may be largely mitigated by a
sufficiently high flow rate.
2. Liquid must stay at the injector at all times while running (fuel pump
nessisary)
A common rail would achieve this.
3. Vehicle must complete a purge cycle before starting similar to a diesel
waiting on glow plugs.
(to rid the fuel lines of vapor).
Not sure about a pre-starting purge, but it occurs to me that the fuel
would need to keep cycling for a while after switch-off if the
under-bonnet heat is a problem.
4. Fuel Pump must be inside the tank, so how do you pass wires through a
fuel tank and have it safe?
I've often wondered about getting wires into the tank in order to make
an effective fuel guage sender a possibility. But in fact I don't
really think it would be an insurmountable problem. Probably quite
easy, in fact - a solid connector embedded in enough vitreous sealant
that passes through the multivalve.
But why must the pump be in the tank, anyway? To prevent cavitation?
BTW
Mixing air/fuel *before* the cylinder breeds backfires and they will cause
serious problems.
Ask anyone tha has used an old Impco system.
Do you mean specifically in the case of *liquid* fuel injection? Why
would this be? ATM all LPG systems mix the fuel and air before the
cylinder.
--
Stewart Hargrave
Finally visible on
www.hargrave.me.uk
I run on beans - laser beans
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