Flexible Fuels

[Bill Allen]

Hi,
Although I'm new to the list, I'm going to jump in here and try to save
you a bunch of parts. I've had a fair amount of experience with nitro in
top fuel drag racing. Although nitro is not as bad as a lot of people
think, it can eat parts faster than you can spit. So, here goes....

	To even get the stuff going, you need a really good ignition, as
in magneto. Even high energy aftermarket electronic ignitions don't have
the spark length to reliably fire nitro. And if you don't get the stuff
lit really well, it'll melt pistons (remember, nitro releases free O2
molecules when it burns, so its like nitrous oxide in that regard).
Keeping it rich will help, but to do that you need an even better,
really good ignition. 

The real problem is that nobody makes an EFI controller that will work
with a mag. Too much electromagnetic interference for it to work,
especially under load. A mag's primary voltage increases with RPM, so it
just gets worse as you go up. 

As for controlling the mixture, nitro needs about 3:1 AFR. Good luck
getting that much stuff in there, even with multiple injectors. Also,
nitro has NO lubrication qualities, it eats most rubber compounds and
creates a nice soupy mess out of your crankcase oil (turns it to
something akin to baby poop!). So the bottom line is that unless you are
racing in a fuel class, have lots of cubic dollars and like to build
motors a lot, I wouldn't mess with it.

Just my spew...

Bill Allen
	-----Original Message-----
	From:	Clive Apps   Techno-Logicals   416 510 0020
[SMTP:clive at problem.tantech.com]
	Sent:	Tuesday, June 23, 1998 6:37 AM
	To:	diy_efi at efi332.eng.ohio-state.edu
	Subject:	Re: Flexible Fuels

	> 
	> Hi everyone, I am the proud owner of a Ford 429 that is going
to get
	> to its next logical step, differing fuels.  I don't know if it
would be
	> methanol would require at least twice the injector duration as
gasoline,
	> and to burn it would probably require one of those fancy
linear oxygen
	> sensors since alcohol likes to be run a bit on the rich side
to keep

	how about 2 sets of injectors
	use both with the alcohol fuel and only the main set with gas
	then you can run only one fuel map and adjust the 2nd injector
size/pressure to
	maintian fuel curve values
	alcohol does not have to run rich, it can be made to run clean
with a little
	tweaking

	> I wonder if it would also be possible to run nitromethane
while playing
	> around, and then switch back to gasoline for the drive home?

	nitrometh needs a lot of timing advance, it is hard to light
	but you should be able to do this
	> 
	> Also, will injectors put up with water, since both methanol
and nitro
	> are sometimes mixed with up to 5% water in order to keep
things nice and
	> cool.

	in solution it should be fine, pure water may not be too great
for injectors
	but you have the fuel as a lubricant anyways
	> 
	> And, since this motor will be used in a 4wd pickup (please
don't tell me
	> I'm crazy, I already know that), will individual injectors
give a big
	> boost in low (sub 1000) RPM torque, or will TBI be good
enough.

	indivudual injectors are better across the entire range, and
give better
	fuel control, distribution and tunability
	> 
	> And last, are there any computer systems out there that can
control
	> boost pressure much like timing, to compensate for the knock
sensitivity
	> of different fuels?

	Turbo and High Tech performance magazine lists a number of these

	> Thanks for answers to any of these.

	Clive