[hotrod]

Thats about what I figured on the probable compression ratio.

I would expect the WI to improve your performance for a couple of reasons.

1. It should improve your engines VE because of the cooling that takes place as the spray partially evaporates in the intake manifold.

2. It would increase your effective fuel octane so yes you should be able to use a more agressive tune.

3. WI improves the thermodynamics of the compression and power stroke.
During the compression stroke a portion of the still liquid WI dropplets are evaportated (or at least cool) the air as it is compressed. This reduces the "negative work" the engine has to perform to accomplish the compression stroke -- that is free power that gets passed to the crank shaft.

During the power stroke the presence of the water injectant gives higher average cylinder pressure even though it lowers the peak pressure and EGT.


Your water sounds like its okay, (especially the rain water) if it's collected in a clean container. One measure of water quality, is if you have very little if any mineral build up in cooking pans or water spotting on glass ware, then the water has a relatively low mineral content. If you want to get anal about it, you could set up a small solar still to re-distill your water also.

If you have concerns about mineral blockage of your spray jets, two suggestions. Set up a regular maint. schedule, buy a couple spare jets, and plan to pull the jets and clean them periodically, some vinegar is supposed to do a good job. The other thing you might do is set up the system with two smaller jets instead of a single jet. This way you have more safety as it is relatively unlikely that both jets would block at the same time. If you get a blocked jet you would still have some water flow.

Larry