Fw: [Diy_efi] compression ratio

[Grant Beaty]

Yeah, problem with alky is that you use it up fast. It doesn't produce a lot
of heat from combustion, and ethanol has a 9:1 stoic ratio, with methanol
being 6.5:1. Both produce about half the power of gas. The methanol is a
little better, because of better cooling and stoic ratio.

The whole point of WI is convenience, so I don't want to be refilling
something all the time. Water has a much greater cooling effect than any
alky, and is denser. So I was wondering how far one can go in leaning out
the fuel with water injection. I was under the impression that the only you
run richer than 14.7:1 is for the cooling effect of the fuel, right? or
wrong?

Grant

-----Original Message-----
From: Mark Williams <mwp at overclockers.com.au>
To: Diy_efi at diy-efi.org <Diy_efi at diy-efi.org>
Date: Wednesday, May 08, 2002 11:58 PM
Subject: Re: Fw: [Diy_efi] compression ratio


>Lots of people on special occasions also mix alcohol/methanol in with the
water
>to give the boost your talking about.  Ive heard of poeple using up to 50%
>alcohol in the water mix, but i guess theres no reason why you cant use
more if
>everything is tuned to it properly.
>
>By Grant Beaty, on Wed, May 08, 2002 at 11:29:50PM -0400:
>> Wow, thats a lot of water. I know this is a bit OT (the thread is
anyway),
>> but if you spray water evenly into all cylinders, can it take the place
of
>> fuel? That is, could you theoretically run 14.7:1 at WOT, spraying water
for
>> cooling instead of fuel? My setup will be 2D mapped, so I can take out
fuel
>> and the water injector's duty cycle increases.
>>
>> My car is limited by octane. And if I increase the octane, its limited by
>> injector. I'd really preffer to kill two birds with one stone and spray
>> something into the motor that will effectively increase the octane and
>> richen it up at the same time. Alky looks nice, but it seems more volume
>> must be sprayed for it to be effective (compared to water).
>>
>> Thanks,
>> Grant Beaty
>>
>> -----Original Message-----
>> From: Axel Rietschin <axel_rietschin at compuserve.com>
>> To: Diy_efi at diy-efi.org <Diy_efi at diy-efi.org>
>> Date: Tuesday, May 07, 2002 9:44 PM
>> Subject: Re: Fw: [Diy_efi] compression ratio
>>
>>
>> >OK, cool. Now 70% of fuel mass is a lot of water to carry around ;-) It
all
>> >depends of the application, of course, as someone else always says :-)
>> >
>> >Now, the ratio I'm used to is more typically around 20% and it serves my
>> >purposes well, of course and as usual, your mileage may vary...
>> >
>> >--Axel
>> >
>> >----- Original Message -----
>> >From: "Greg Hermann" <bearbvd at mindspring.com>
>> >To: <Diy_efi at diy-efi.org>
>> >Sent: Wednesday, May 08, 2002 3:00 AM
>> >Subject: Re: Fw: [Diy_efi] compression ratio
>> >
>> >
>> >>
>> >> At 12:53 AM 5/8/02, Axel Rietschin wrote:
>> >> >From: "Greg Hermann" <bearbvd at mindspring.com>
>> >> >> >> > BTW... ive heard that the maximum water that can be injected
>> >before
>> >> >> >> > water-lockup can occour is 50% of fuel.
>> >> >> >>
>> >> >> Apparently you have a good source for urban legends---
>> >> >
>> >> >Water-lockup is indeed probably a little further away ;-) but 50% of
>> fuel
>> >> >mass was indeed experimented by someone (Harry Ricardo? - I don't
have a
>> >> >quote handy so please don't ask) and is most probably the most water
you
>> >> >ever want to inject.
>> >> >
>> >> >This may be helpful:
>> >> >
>> >> >http://retro.co.za/efi/DIY_EFI/2000/efi5-039.txt
>> >> >
>> >> >
>> >> >--Axel
>> >>
>> >> 70% of fuel mass flow is a bit closer to the theoretical maximum
>> (optimum)
>> >> H2O flow rate which is beneficial--as supported both by thermodynamic
>> >> calculations (the maximum increases somewhat as compression ratio
>> >> increases). and by Sir Harry's work.
>> >>
>> >> Sir Harry went quite a bit FURTHER than the optimum, proving also that
>> >> water flow above the optimum simply results in reduced power and
>> >> efficiency, not in engine damage!
>> >>
>> >> Greg
>> >>
>> >>
>> >>
>> >> _______________________________________________
>> >> Diy_efi mailing list
>> >> Diy_efi at diy-efi.org
>> >> http://www.diy-efi.org/mailman/listinfo/diy_efi
>> >
>> >
>> >_______________________________________________
>> >Diy_efi mailing list
>> >Diy_efi at diy-efi.org
>> >http://www.diy-efi.org/mailman/listinfo/diy_efi
>>
>>
>> _______________________________________________
>> Diy_efi mailing list
>> Diy_efi at diy-efi.org
>> http://www.diy-efi.org/mailman/listinfo/diy_efi
>
>_______________________________________________
>Diy_efi mailing list
>Diy_efi at diy-efi.org
>http://www.diy-efi.org/mailman/listinfo/diy_efi


_______________________________________________
Diy_efi mailing list
Diy_efi at diy-efi.org
http://www.diy-efi.org/mailman/listinfo/diy_efi