[Diy_efi] Evaporative fuel injection (evolution of the evap carby)

[Ben P]

Phil:

It appears I was a little off the temperature mark... So in the example you 
described, the vapour is made in a seperate canister using a heating element 
that draws near on 100 amps (at 12 volts) in conjunction with the exhaust 
heat to completely vaporise the fuel. There is also a second reservoir, and 
a set of injectors. Is this correct?

>From what I can see the gas production works much like a carburettor 
accellerator pump circuit... The gas is produced/boiled/whatever in the heat 
exchanger until it reaches a certain level/pressure (like a float), from 
which it is moved into the 1L reservoir (much like an accell pump). When it 
is needed it then flows through the injectors and into the intake (like the 
pump when it is working).

This seems like a good system to me, and in operation, I cannot see much of 
a difference between that idea and my own (parts list is completely 
different, and the way it works is too, but the end result of hot fuel vapor 
being injected in a multipoint configuration is the same.

Adam:

Yes I can see your concerns about the heavier parts of the fuel condensing 
again, but given the short length of port between injector and inlet valve, 
the fuel condensing could not possibly be any worse than a normal injector. 
Also injecting fuel as a gas, the gas can be far more directional (fuel has 
to be sprayed, and as we already have a vapour in this idea we can point it 
in one direction and straight into the combustion chamber, the vapour does 
not have to come near a port wall if the ports are straight enough. Yes its 
possible, but it shouldnt happen in most situations and the amount it 
happens would be negligible (and hence its effects would be too).

And my calculations for the horsepower loss were based on 100% air in the 
intake, with no fuel going in (like a direct injection setup), and the 
percentage of air in the mix with gaseous fuels (ie my idea), at a rich 
mixture of 12:1. So the same numbers would apply to the port fuel injection 
(a 7.5% loss due to displaced air).

Also, with the change in throttle problem, the idea was to run the engine at 
14.7:1, which isn't rediculously lean (however lean running would be 
possible). Maybe the blocks could have an accellerator pump of their own (ie 
a surge of power/heat) to cope with the sudden fuel loads it will get. 
However it may be neccessary to have a normal injector at the throttle body 
to cover extreme conditions.

Bernd:

Maybe water injection is the solution to the high combustion temps 
associated with lean burning. Admittedly it means more things to fill, but 
all joe blogs needs is a great big light to say there isn't much water left. 
We all know he is already capable of putting a bottle of valve saver/octane 
injector/miracle juice into his tank, so opening his bonnet and pouring it 
in there shouldnt be a problem. A failsafe (reverting to stiochimetric 
afr's) could also be introduced if someone forgets.

Maybe a rethink of the blocks is in order, maybe this idea needs a spray 
onto a hot block to work more efficiently...

cya
Ben

_________________________________________________________________
Advertisement: Meet Sexy Singles Today @ Lavalife - Click here  
http://a.ninemsn.com.au/b.aspx?URL=http%3A%2F%2Flavalife9%2Eninemsn%2Ecom%2Eau%2Fclickthru%2Fclickthru%2Eact%3Fid%3Dninemsn%26context%3Dan99%26locale%3Den%5FAU%26a%3D23769&_t=754951090&_r=endtext_lavalife_nov_meet&_m=EXT