My latest engine has started to ping a little on long hills with medium throttle. Probably accumulated a little carbon which I will try to clean out but................

I'm looking at a water injection system by Spearco who were bought out by Injectronics I think. No. 740 for non bown engines. Anyone running such a system? Thoughts on it before I reinvent the wheel?

 

I would back the timing off or use a better ocatne fuel, first. Just my opinion though, later

 

Well thanks but I already did both. Problem seem to get worse after a new Flowmast exhaust system. I also went up two jets in the carb.

 

What is the engine compression? How old is the motor? How big a carb you running? What is the cam specs? Have you done a compression test? Is your timing in the distributor mechanical or vacum advance correct? Hopefully someone will be able to help so you can run it without a water injection that would be my last resort as I am sure you feel your at. later

 

I've always had interest in the water injection units. I twas used in the P51 Mustang in WW11 to inable more power without detonation. It cools the fuel charge and combustion chamber allowing more timing for more power. As JWTailor said though, I'd try to figure out the problem before I started throwing money at it. If you think you have a carbon buildup problem that would cause spark knock or detonation for sure.
Some people get away with misting water directly into the intake through the carb which will clean out your combustion chambers real nicely. I've never done it so I will not recomend it.
Someday I'll try my hand at the water injection theory though.
Check around. I found several sites with plans for a homemade kit for it.
Clint

 

Update: It's a pretty new engine in excellent shape. Maybe 10:1 compression. 750 Speed Demon. I can compensate for the problem and plan to "decarbon" it but still the water injection would allow me to run more advance and possibly even drop down to the middle octane fuel. It would also keep the combustion areas very clean.

The problem isn't really severe. I would just like to optimize everything.

 

YOu know there is a possiblility that the gain or hp increase would be minimal at best if you used the water injection, just a thought. If it is a fairly new engine that ran fine for a while after the rebuild but now you are for sure there is carbon buildup maybe the old carb is running too rich and needs to be tuned. Just throwing out ideas. How many miles on the engine before you noticed the knock or was it always there? What do your plugs look like?

 

one more trick if water dosen't remove the carbon build up you suspect would be to pour ATF down the carb. run the engine at about 2K rpm so not to foul the plugs. 1/2 a quart or less should do it.
be reminded you are going to making a ton of smoke. I wonder if James Bond used that one. anyway good luck.

 

A product is made specifically for this purpose, of removing carbon. This is called SeaFoam. You slowly pour it down the carb at idle with a hot engine. It's got lubricants in it to keep the cylinder lubed during treatment, and solvents to remove the carbon. I've had good luck with it in my 360. I think it's a little safer than water, since it lubes, and probably better than ATF, since ATF is oil and would probably end up causing more carbon to build up.

Good luck.

 

Have you recently changed the plugs? a spark plug with a heat rang thats to high will cause ping as well, does your distributor have advance springs in it? maybe they've stretched a little and need to be replaced, just some more ideas to consider. good luck! DW

 

Plugs were good last time I looked. Already stocked up on Sea Foam. I want to put the baffles back in my aluminum valve covers first as I think I'm getting a little oil through the PCV which might be causing the problem.

 

As far as a water injection goes, look at these folks.
www.snowperformance.net
It seems that water injection is making a come back. Volvo is putting it in some of their cars from the factory. Alot of the road course and Rally drivers use it. I think there is alot of potential there, you just can't do it with an old windshield washer motor and expect good results. I believe you'd see good results with the Snow set up or the Aquamist but who has $500 to spend on something like water injectionm I know I don't.
I have'nt given up on it though, just need to work out the cheaper way too do it. Need a high pressure pump with a very fine nozzle and some way to regulate the flow. More throttle equals more flow. Anybody have any ideas?
Clint

 

I think you started a good topic beartracks. looks like this really is a common thing now. if its safe for aviation why not put it to other uses.
sounds like a cool project. make a low budget prototype to get the idea on the benifits. you could use a nitrous plate with a spray bar or something. maybe just a cheap 50psi fuel pump and anything with brass or aluminum parts for plumbing it in would work. throw in a throttle switch and some relays and down the road you go, but faster.
but is there any additives you would need to use in your water supply? just a thought

 

Well I still like the Injectronics unit at $275. It's been made for a while and seems suited to street use. I generally don't like the idea of having to add anything to the water. I don't want to build my own because I like the idea of computer modulated rate. One need to be very careful not to have something fail and inject too much water. You could damage the engine.

I may make a move in a couple of months and will repost if I start the project.

 

Alot of people are running water and methanol at a 50-50. Read where one guy was using hydrogen- peroxide and water. Said it gave it a good boost.lol Peroxide is a form of rocket fuel is'nt it?
Clint