Cheap DIY EFIE

[jamminjimmy]

great idea! Along the same lines, a carefully selected overtemp switch(snap switch, whichever you want to call it) could also be used as a failsafe, or as the trigger to switch back to normal, closed loop O2 signal. I believe they come as normally open OR normally closed switches....

I only mention this because I'm a cheap b?st?rd and might have access to something like that cheap.... And, for my case, I don't want to go too lean, just want to get back to a normal-ish O2 signal with any mod I install....

I would imagine an EGT would be a better feedback device, letting you see what temp your at along the way.....

[ShadeTreeMech]

My engine is largely aluminum (except i assume the cast iron sleeves and rings and valves) so I think injecting water would help increase MPG by adding more water vapor to the exhaust, which would cause the engine to run "leaner" I think without having to worry much about rust buildup.

Does anyone have a clue on how to make a 4 stroke work as an 8 stroke? There's old engine designs that would skip every other intake event and simply pump in air. If i could flip a switch to get the injectors to skip every other signal, I'd have an 8 stroke, and running plain air into the cylinders wouldn't hurt anything. I'd lose power and would have to open the throttle more to compensate, but if I'm not mistaken that would be more efficient, correct?

[daring4]

If I remember correctly, Jim Crower designed a camshaft for an engine that was a six stroke. Intake, compression, combustion, exhaust, intake of water mist, steam bath.

[busypaws]

I live here in AZ. In the summer (9 months of the year) we have low humidity and high temps. My 95 Toyota PU would start pinging when it got over 90 and less then 20% humidity. So I thought - add humidity! So I strapped on old plastic soda bottle to dash, put a small irigation hose and a dripper on top of the air intake filter. Now I just carry a 2 liter bottle of water and fill up the small bottle on the dash every 20-30 minutes.
It stops the pinging on hot dry days. It's not a water injector but it helps my truck here in the desert. A "swamp cooler" for my air intake.

[mpgx2]

My experience of DIY water injection is this, go find a cheap kit
somewhere and *don't* DIY.

Buy then modify..

Here's my experience of DIY water injection.

$200 Kit on ebay....

versus..

* buy water pumps from china $50 each plus $40 postage

* water nozzle, $30 plus $20 postage

* solenoid $10 + $15 postage

* arduino controller $40 + $15 postage

* 3 weeks anguish at not having it finished

* 3 weeks fuel loss by not having the kit at $20 per
week = $60

Total cost = $260

I'm not suggesting ebay necessarily. Just by the time you
add it all up and all the postage some of the premade kits
do make sense.

Maybe I'm just doing it all wrong.. lol

[robertwb70]

I've been thinking about lean burn too but I'm leaning toward a more involved solution.

Thermal barrier coatings on piston tops, combustion chambers and valves, should allow running as lean as lack of pinging will allow with no melted parts. While I'm at it might as well get a dry film lube coating on the skirts and bearings too. Last time I looked into cost it was looking like a couple hundred dollars to do all this, but that was a few years ago.

Not real practical for someone who doesn't want to take the engine apart though...but if you have a spare engine to build or have it apart anyway it's good stuff.

[mpgx2]

Traditionally, there are two ways of approaching efficiency, run hotter
or cooler.

Theoretically, if you take the run hotter approach then you are
losing heat and therefore losing energy.

The ol' opel-T1 376mpg vapour car had their engine in a heat box. I would
love to know if they had their motor running ultra-hot or ultra-cool.

[PowerHaus930]

does anyone have a link to someone that has damaged their engine with an EFIE or similar device?

[steve-o]

Originally Posted by mpgx2

What I am working through at the moment is combining
water-injection with lean burn.

I am led to believe that one third of fuel is used as an
internal combustion chamber coolant.

During combustion, it's the vapour that explodes and
the fuel liquid is just exploded and sent to the cylinder
walls to cool them.

If you go lean, you are just reducing the fuel component
that was destined for 'cooling'. That's why everything
'goes hot'.

Apparently, you can substitute that fuel for water and
it will achieve the same effect.

i was under the impression that the reason an engine heats up while running lean is that the explosion in the combustion chamber travels at a slower spead allowing the heat time to transfer into the metal around it. this slower spead also decreases power output of the engine and raises the temp of exhaust gases going past the exhaust valve, if there is a flaw in the metal of the valve it has a chance to burn at that flaw.

[mpgx2]

Well I am not sure that more fuel will burn faster than
less fuel. One would expect a smaller amount of fuel
to burn faster than a larger amount.

If what you are saying is that in a lean burn combustion
the fuel is burnt quicker so there's time to spare after
for heat transfer to the metal then sure, that's logical.

It all comes back to the same thing and that is that
too much fuel is going in and too much heat is being
generated.

So it may well be that what we consider 'lean' is
still way to 'rich'.

I like what others are talking about in only running
lean under certain conditions. It makes sense to me
to be changing from lean to stoic and back on the
fly according to different factors.