More water = higher egts?

F

Farmallgray

New member
I wanted to get you guys thoughts on something. This is on my pulling garden tractor with a turbo'ed 3cyl kubota engine. It has a 250 psi water injection pump.

I have been playing around with
different combinations of water nozzles and came up with an odd thing. My
current setup is 3 90 cc nozzles (one in each intake port) and a single 250cc
nozzle in the crossover pipe. With this setup my EGTs run around 1600. I tried
replacing the 250 with a 90 and a 180 (which would add up to 270) and it runs
hotter at about 1700-1750 deg. I can't understand why it runs hotter with
slightly more water. I'm running straight distilled water. Any ideas?
 
Forrest Nearing said:
probably not atomizing as well
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That is something I had thought about. But I'm wondering if that is good or bad? I prefer the lower EGTs since I'm getting ready to up the fuel by making the delivery valves "full cut".

What do you see as the advantages or disadvantages of either nozzle setup?
 
Is power any different? Too much water will quench combustion and delay ignition, leaving more fuel burning into the exhaust stroke.

I'm getting ready to up the fuel by making the delivery valves "full cut"
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Don't. DV's work different on high speed IDI engines. Cutting off the collar will cause pressure waves to push the needle off its seat and inject late into the stroke. You'll get more power for sure, but it will smoke like hell no matter how much boost you push into it (because of the late injection) and the EGT's will be as hot as such. If you want more fuel without the heat the best way is to increase the plunger size, more fuel in the same injection time.
 
fire power said:
Not to derail but where in Pa do they have classes for garden tractor's?
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I'm in central Pa (State College area) and there are lots of garden tractor pulls in the area. But so far no classes for diesels. So I'm trying to get something started by pulling mostly exhibition. Some places have a class where they pull tractors with 1.0 liter 3cyl Geo metro gas engines and they let me pull with them.
There was a class for diesels at the Keystone Nationals back in March at the Pa Farm show complex in Harrisburg.

Here is a video from that pull;
http://www.youtube.com/user/farmallgray?feature=mhee

I ended up third.
 
300D said:
Is power any different? Too much water will quench combustion and delay ignition, leaving more fuel burning into the exhaust stroke.
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That is the best explanation I have seen so far. I don't notice any difference in power. At one point I tried the 250cc and a 90cc together at that was too much. It only made it part way down the track and died. Here is a video of that pull;
[ame="http://www.youtube.com/user/farmallgray?feature=mhee#p/u/2/MW9QOrcDuA8"]http://www.youtube.com/user/farmallgray?feature=mhee#p/u/2/MW9QOrcDuA8[/ame]
After the first hook, I removed the 90cc and was running only the 250cc with the 3 90s in the intake ports.

Here is another video using the 90 and 180;
[ame="http://www.youtube.com/user/farmallgray?feature=mhee#p/u/1/0dMG503f-oY"]http://www.youtube.com/user/farmallgray?feature=mhee#p/u/1/0dMG503f-oY[/ame]
Different track and different sled, so it is hard to tell about any power difference.
 
300D said:
Don't. DV's work different on high speed IDI engines. Cutting off the collar will cause pressure waves to push the needle off its seat and inject late into the stroke. You'll get more power for sure, but it will smoke like hell no matter how much boost you push into it (because of the late injection) and the EGT's will be as hot as such. If you want more fuel without the heat the best way is to increase the plunger size, more fuel in the same injection time.
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Well, here is the thread where it was suggested for me to cut them;
Pump timing - Competition Diesel.Com - Bringing The BEST Together

I had thought about it for a long time and finally had decided to do it. Now you go and burst my bubble ;-)

For what I'm doing, more smoke is probably a good thing because it doesn't smoke at all now. I get tired of everyone asking why there is no smoke if it is really a diesel ;-) I am a little concerned about the higher EGTs though. I really wish I could find a spare set of DVs so that if I didn't like it, I could go back.
 
Well, mystery solved. I did a little somewhat scientific testing for volume on the different nozzles. I tested each one individually by hooking them to the pump, spraying into a cup for 10 seconds and measuring with a big syringe. The 250 cc nozzle flowed about 30% more than the 90 and 180 combined. So that is why it runs cooler with the 250. I guess the nozzles were mislabled or something. I'll have to do a little calculating and see how they compare to their specs.

I did check the pressure and it is running 175-200 with all the nozzles flowing and doesn't change with different combinations.
 
300D said:
Is power any different? Too much water will quench combustion and delay ignition, leaving more fuel burning into the exhaust stroke.


Don't. DV's work different on high speed IDI engines. Cutting off the collar will cause pressure waves to push the needle off its seat and inject late into the stroke. You'll get more power for sure, but it will smoke like hell no matter how much boost you push into it (because of the late injection) and the EGT's will be as hot as such. If you want more fuel without the heat the best way is to increase the plunger size, more fuel in the same injection time.
Click to expand...

why do they work different? I ask because i was about to do this tommorow on a idi nissan
 
Farmallgray said:
For what I'm doing, more smoke is probably a good thing because it doesn't smoke at all now.
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Thats a very good thing. People need to show diesels can make serious power without sh!tting a cloud of smoke. The fact people ask "why is there no smoke" shows the public ignorance. They're the same kind of people that think a car doesn't have a turbo if it doesn't have a farting blowoff valve.

When I tried them I just got a bad idle, smoke and extreme EGTs.
[ame="http://www.youtube.com/watch?v=HUUxhb4Rd9w"]http://www.youtube.com/watch?v=HUUxhb4Rd9w[/ame]

Visibility is crap in this video, but you can see how fast the needle pegs to 1500*f.
[ame="http://www.youtube.com/watch?v=87x5gdpASO8"]http://www.youtube.com/watch?v=87x5gdpASO8[/ame]

jeff115 said:
why do they work different? I ask because i was about to do this tommorow on a idi nissan
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IDI injectors are little more than a check valve and they work at (relatively) low pressures, the extreme heat in the prechamber does most of the atomizing. The low pressure and low flow resistance though the nozzle makes the pressure wave push the needle off the seat easier.
 
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I'd still like to try it. But you have me convinced to find an extra set of valves so I can go back to stock if I don't like it. Anyone know where I can get a set? Maybe I'll try asking on another topic.
 
If I were you, I'd go full cuts and never look back. You will make more power period.

As far as EGT's, cross that bridge when you get there.

As far as smoke, if you are building a street legal EPA compliant vehicle it's a valid concern. On a competition-only off-road vehicle, smoke should be one of the last considerations when it comes to performance enhancing parts or fuel injection tuning.
 
Big Blue24 said:
On a competition-only off-road vehicle, smoke should be one of the last considerations when it comes to performance enhancing parts or fuel injection tuning.
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Actually it should be the first. Smoke is pure wasted power, fuel that could be burned to pull the sled further or accelerate it faster for more momentum as weight shifts.
 
300's eternally false axiom of Diesel tuning: a Diesel engine stops getting additional power from additional fuel before it starts getting visible smoke from additional fuel.
 
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