H20 injection naturally aspirated head temp test with results

[slalombuggy]

I took a different approach to using water to cool my Bonneville race engines. I use a washer bottle from a Honda and the hose that goes to the cowl with a Weber main jet in the end of it and spray it into my fan, directly into the center of the alternator shaft. It will drop the head temps 40* in about 30 seconds. I have it set up with a micro switch on my steering wheel that I start to activate as I cross the 3/4 mile marker on the short course and about the mile and a half on the longer run. The only problem I encountered was when I first started using it. I didn't have the plugs and wires sufficiently waterproofed and I would get a misfire after about 30 seconds of continuous spray. I played with different size jets till I found one that was the smallest I could run and still get the same cooling in the same amount of time. I've since junked the washer bottle and just run the pump from an outlet on my intercooler tank.

brad

[67rustavenger]

[BFB]

[94touring]

I don't have any return lines. The in line pressure valve in my situation just doesn't allow the entire line from the pump to drain out the nozzle. There is however some fluid between the nozzle and pressure valve that is going to gravity feed out...and a moment of high pressure built in the lines that pushes fluid past the pressure valve as the pump shuts off.

[slalombuggy]

[94touring]

45cc nozzles tested. Same long hill into strong wind today at 75mph. Low pump setting gave 40-44f lower temps in multiple test and high pump setting gave 56-60f lower temps. High pump at light cruise gave no indication of hesitation or ignition hiccups.

[67rustavenger]

[94touring]

[94touring]

Another day of test. Upped the meth to 50%. Went down a half on idles, a half on mains, and from 200 to 215 on airs. Set the trigger switch on the idf to kick in earlier, maybe around 20-25% throttle. I have a lean cruise under 60mph up to 18:1 without it engaging. 60mph is 17:1. 70mph would be in the 16s but the h20 is engaging by then and knocks it into the mid 14s. Had a steady head temp of 275 degrees at 70mph but it's not exactly a hot day either. Light load throttle is 14s, more load 13s. WOT without H20 is creeping into the 14s above 4k rpms, but back to 12.8-13.3 with it engaged. Only issue is a richer than usual dip around 3000rpms with it engaged. I have some jetting combinations once I order more to try to see if I can clean that up. No lean hesitation spikes and runs strong. Very happy with this.

Looking at cost, tractor supply has -20 washer fluid (30% meth) for $3 a gallon. A local speed shop sells pure meth for $5 a gallon. Figuring in cost of distilled water, that still comes out to about $3 a gallon. My 6 gallon supply spraying on low should in theory spray a little over 4 hours if it were to spray continuously. I may or may not stay at 50% meth, will just need to see how the final jetting works out.

[oprn]

It would be interesting to track fuel economy with the different mixes too.
_________________
Our cars get old, we get old but driving an old VW never gets old!

[94touring]

A few more days of testing and a bit more tuning than I'd hoped for. In the end all I really did was up my air jets to lean high speed cruise out a bit and above 4k rpms at WOT, which pairs well with the water/meth when it kicks on. I tried several combinations and while I could go down 10 on the mains and run my pump on high continuously and achieve good air fuel ratios, what I found was it begins to contaminate the oil, leaving a milky goop in the valve covers. Inspecting valve covers with intermittent spray on low pump hasn't shown issues like that as of now. Spraying as needed in a high load situation seems to be the way to go. Full 300 psi pump output on 45cc nozzles is too much, at least for long durations. I have a 200 psi pump on the way to test out on at the lower pump settings. It might be a good balance between cooling and not getting water in the oil if it were to run continuously in harsh driving conditions on a 100psi setting. Also have done a couple compression test, one before and after the milky valve cover drive, both results came back at 150psi.

[oprn]

What are your oil temperatures? Maybe that needs to be higher.
_________________
Our cars get old, we get old but driving an old VW never gets old!

[94touring]

They hang between 180 and 200 on a normal day. I have a very large external cooler and 180 thermostatic control. It's basically impossible for me to go over 220. Either way, I will take it as a sign It's too much h20 on full pump running continuously.

[SGKent]

[94touring]

Yep. You'll see bigger differences in AFRs with more meth added or subtracted. I've been doing a 50/50 mix during all the testing the past several days. On a low output I may see .75 +/- afr difference. On full blast it becomes more like 2afr. On my 130 main drive the engine was more or less undriveable without meth, sitting 19+afr on cruise. With the meth it was 16s-17 afr on cruise. And drove great honestly. So what I've done is got my high speed cruise leaner than I'd normally run, so that when I'm getting into load with the system kicked on my AFRs are about where you want them for max power, 12:5-13 afr. And if I'm winding it out to 5k rpms on a shift, I'm not ultra rich. I will end up just leaving the system off most of the time, but when I'm doing one of my cross country drives, or pulling my gear locally up some of these hills, wind, ect... can engage the system and get 40 degrees knocked off the heads. And mountain drives can reduce the meth % to help AFRs. I have a 5k mile drive coming up in August and will need all the cooling I can get.

Tuning saga related, I had an issue with my floats being on the ragged edge of overspilling into the throttle bodies. I had the carbs on and off about 100x the past week and changed some gaskets. It altered things just enough I caught that one side was for sure leaking over on me, and probably had been for who knows how long. This threw a curveball in my tuning with getting them set high enough I didn't get a lean 19afr spike that gave a flat spot, but not so high they weren't spilling over. I've been somewhere around a 140 and 142 main. I was running a 142 main and 215 airs for some time but after tearing things down this winter and lapping valves settled in on 140 mains and 200 airs. I was hoping to use a 138 main with this injection but after the floats were finalized just couldn't get past that lean flat spot, so the 140s stayed and instead of 200 airs put the 215s back in. I can get away with a lean spot of low 18s with the 140s without it getting fussy. The whole idea of a 138 main was to help out with a little sidewinder dip around 3k rpms at WOT. This is super picky detailed tuning. I have it about 95% perfect, which for carbs probably isn't so bad. My lean cruise window is pretty wide now after all the fiddling, so I should see some slight mileage gains.

[94touring]

Have some fuel mileage stats, but without water/meth spraying. Took a week of driving it in various conditions and different driving styles to see how it does if the system were to fail. In otherwords, can I get home. With it being tuned for W/M but without it spraying I'm limited to 4300-4500rpms WOT before it gets too lean. Which isn't a big deal because I'm not normally winding it out beyond that unless I really need to merge into fast traffic. Light throttle cruise AFRs (no load, strong wind, hills, ect) is pretty much high 15s to 17s across the board up to 70mph. I seem to have gained 3-5mpg like this. Here with rolling hills back and forth to my shop this gives me low to mid 20s MPG. My high speed cruise mileage improved the most as I was already tuned lean of peak below 60-65mph. I have a new pump in that's 200psi vs the 300psi pump in there now. When I get a moment from other projects want to time the 45cc nozzles on low pump (approx 100psi) to see what the final output is, how the spray pattern is, and what the temperature reduction is on low. I know on 200psi I can expect up to 50F temp reduction. The next mileage test will be with it kicked on at low. I believe I will see a slight increase in mileage with it spraying, not necessarily continuously, but mostly continuous. The reason being that on a flat stretch of road doing 60mph with a rock steady foot and AFRs in the 17s, kicking the system on will accelerate the bus 3-4mph. Turn it off and it slows. I can maintain speed up slight grades without increasing throttle and just kicking on the W/M. I should in theory be using less throttle with it spraying and gain a little something.

[94touring]

Couple more updates. Bench tested a different pump controller, a generic Amazon Chinese unit with heat sinks and 15a fuse. 2v sent to a 200psi pump on the bench results in the pump barely turning at what I'd describe as a slow heart beat. Nozzle output doesn't begin to atomize on the bench till 2v and still results in 45cc output. Once in the bus with the pump pushing fluid up and around and through the check valve requires 3v to get the same spray. High pump operation results in the pump getting too hot, whereas low volt barely turning it never gets hot. They are duty limited. Appears it can run continuously at low output. Fluid loss results after tapping the filter base plates and collecting the overflow were interesting. Collected almost exactly 1 quart in 1 gallon of fluid sprayed. This would account for a 33% loss at cruise, which probably is ideal for water volume per HP output at cruise. Would also appear there's less fluid loss at WOT just going by AFR numbers. Cruise is effected between 0.5 and 0.75 AFR and WOT is 1.25 AFR +/- making sense because more intake velocity should be drawing in more water/meth. All that to say two 45cc nozzles seem to be about perfect for what my power range is. Getting warmer this week and will continue to compare head temps.

[sidemarkers]

[94touring]

More updates after more time and driving. Continuously spraying on low doesn't show signs of milky gunk in the valve covers. Some condensation on the back side of the oil filler cap as moisture is being released. Oil pressure isn't dropping or level being affected. After driving around a considerable amount with and without it spraying continuously, I prefer continuous. It just feels more responsive. Lean of peak cruise power to a not as much lean of peak equates to a better feel. I tried to get the overflow to return back to the water cell but with a full tank it back flows to the carbs. Thought about just having catch cans that I could empty back to the cell occasionally. In the end I went with catch cans where the vented caps are lower than the filter base plates, they're Td together and run to a container beside the water cell that can easily poured over into the cell, and importantly using a filter to keep debri out. If the overflow gets too high this way, worse case it pisses out the catch can vent caps and not into the carbs.