Date: Sun, 25 May 2008 12:23:20 -0400
Reply-To: Greg Potts <greg@POTTSFAMILY.CA>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Greg Potts <greg@POTTSFAMILY.CA>
Subject: Re: [SPAM] Re: Water Injection
In-Reply-To: <00a401c8be70$e9773f20$0c00a8c0@OWNERMIKE>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Hi Mike,
This is where I think Megasquirt could come in handy. With programming
to include the input of a knock sensor, a water/ethanol injector could
be brought online as needed.
I think that in the internal combustion engine there is also a benefit
in the creation of steam. The small amount of water injected into the
cylinders expands as it converts to steam, and I believe that this also
adds to the energy generated by combustion. It might be merely a few
percent of improvement, but when one considers the cost differential
between water and gaoline, the results are certainly worth pursuing.
The downside:
We're double-thinking the original designers of the engine, so there are
bound to be some drawbacks. Here are a couple that I have considered:
1. Restricting the flow of water. I have heard a few reports of persons
using a vacuum-drawn system who have experienced problems with the water
supply draining into the engine when parked, flooding the intake and
rendering the engine inoperable until the spark plugs are removed and
the water ejected.
2. The continued presence of water in the combustion chamber will lead
to oil contamination. At the very least, water injection users should
consider increasing their oil change frequency, particularly when the
vehicle is being used for short-trip commuting.
3. Vacuum leaks: Once the water supply has been exhausted, the system
will allow unmetered air to enter the system. This will lean out the
mixture, creating more heat rather than reducing heat. A water level
monitor is highly recommended, as is the development of a water tank
equal in range and convenience to that of the gasoline tank.
This system is not hard to implement with off-the-shelf components, but
adapting them to automotive application is certainly not without risk.
But with gas at over $4/gallon, I think some risks become worth managing.
Mike wrote:
> This basic priciple of physics applies to ALL engines, including
> reciprocating engines like those in our Vanagons!
> When I was stationed in Okinawa ('82 - '85), I rigged a homemade water
> injection system on my '70 VW Squareback with dual carbs. I can describe
> exactly how to anyone interested.
> It does two things; it quenches pre-ignition in a reciprocating engine
> (preventing engine knock/ ping to eliminate detonation from pre-ignition by
> cooling the charge in the cylinder. It also, will augment thrust output
> (HP) a small amount, but in an under-powered vehicle every little bit
> helps,
> when you need it. Obviously, this has its limits both in amount and
> duration applied. Too much quantity and you'll quench the combustion
> completely. Too long and you'll use up your limited supply onboard.
> It was nice to be able to hear engine ping starting, then press the
> momentary switch that I'd mounted on my automatic's shifter, and apply
> water
> just long enough to overcome the uphill load situation that was causing
> detonation.
> I think it's time to experiment with this age-old technology, to see if it
> helps the Vanagon engine........
>
> Mike B.
>
>
> Subject: [SPAM] Re: Water Injection
>
>
>> Definitely, the engines that had trouble water getting into the
>> combustion
>> chamber, had their insides immaculately clean and the cooling was great.
>> Zoltan
>
--
Happy Trails,
Greg Potts
1973/74/79 Westfakia "Bob the Tomato"
1987 Wolfsburg Weekender Hardtop
www.busesofthecorn.com
www.pottsfamily.ca
| 
