Spraying water into a hot engine

I love this guy! I hope I get to meet him next time I too travel around said block.


Best poster since pflemming by far! :cheers:
 
99d.jpeg
 
not that i agree with the OP in any manner.... for your consideration... an air cooled water vehicle...

VW_Schwimmwagen_1.jpg
 
It's the name isn't it? I just can't get any respect calling myself Horse.

Shoulda thought that one through a bit... Can an admin change it for me?
 
Horse said:
Hey I'm done I got my answer it was in the first few responses. One word: Rain. More water gets dumped into that engine flying in rain than my maybe 2 gallons of warm spray I got into that engine.

Thanks for the help guys. No seriously THANKS.
Click to expand...
I actually hope they find the engine damaged now...
 
ircphoenix said:
I'll hide behind my yoke while you shake your fist angrily at me from the ground, next to a shelled out rental engine. =D
Click to expand...

Not me. I don't shake fists at anyone. I'm a gentle soul.

tumblr_static_filename_640_v2.jpg
 
Another point to consider is an engine continuing to produce heat in a cold environment vs an engine not producing heat suddenly exposed to cold. Possible to damage the engine? yes. Likely? well that depends on the delta-T (spelled out since I cant find the fancy symbol). But since none of us have extensive study in metal reactions to thermodynamic changes, we'll never know. Troll on
 
gitmo234 said:
Another point to consider is an engine continuing to produce heat in a cold environment vs an engine not producing heat suddenly exposed to cold. Possible to damage the engine? yes. Likely? well that depends on the delta-T (spelled out since I cant find the fancy symbol). But since none of us have extensive study in metal reactions to thermodynamic changes, we'll never know. Troll on
Click to expand...

See AC 20-105B, 4. g.

Do you think the FAA just made it up?
 
GlennAB1 said:
See AC 20-105B, 4. g.

Do you think the FAA just made it up?
Click to expand...

I know they didn't. I ruined a car engine when I was 16 because of my sarcastic comment above. It was my first car, it over heated, so naturally i wanted to cool it and I filled it full of cold water ASAP. CRACK.

I'm referring to all the other scientists on here comparing apples and oranges to come to conclusions on potatoes
 
And as a follow up, last year I was in a graduate space systems engineering class and we had to address this very issue while designing satellites. When the sunlight hits its extremely hot. When it stops the temperature suddenly drops. Causes all sorts of nasty problems (like cracking) since it's not producing any (significant) heat of its own.
 
GlennAB1 said:
See AC 20-105B, 4. g.

Do you think the FAA just made it up?
Click to expand...
That is how it usually gets done.

I don't see the relevance of the AC to the OP's case. nothing there about quick cooling of the aluminum of any part. just the pilots make mistakes and cause engine failures.
 
gitmo234 said:
I know they didn't. I ruined a car engine when I was 16 because of my sarcastic comment above. It was my first car, it over heated, so naturally i wanted to cool it and I filled it full of cold water ASAP. CRACK.

I'm referring to all the other scientists on here comparing apples and oranges to come to conclusions on potatoes
Click to expand...
When did we start making aircraft engine from cast iron? If your engine were under 300 degrees do you think it would have cracked?
 
Tom-D said:
That is how it usually gets done.

I don't see the relevance of the AC to the OP's case. nothing there about quick cooling of the aluminum of any part. just the pilots make mistakes and cause engine failures.
Click to expand...

"Engine cylinders and valves can be damaged by thermal shock if the engine is not properly warmed up, prior to full power applications, or the cylinder heads can crack by allowing the engine temperature to cool off too rapidly in long gliding descents at reduced power."

(countdown until this post is either answered with a question or "that says nothing about aluminum")
 
Tom-D said:
When did we start making aircraft engine from cast iron? If your engine were under 300 degrees do you think it would have cracked?
Click to expand...

Please go on and tell me the make and model of my car since cast iron engines began being phased out in the early 90s and aluminum started becoming more popular. The likely hood of cracking depends on the metal as much as thermal difference
 
gitmo234 said:
"Engine cylinders and valves can be damaged by thermal shock if the engine is not properly warmed up, prior to full power applications, or the cylinder heads can crack by allowing the engine temperature to cool off too rapidly in long gliding descents at reduced power."

(countdown until this post is either answered with a question or "that says nothing about aluminum")
Click to expand...
you, like many, have missed the point again. A drop temp from under 300 degrees to ambient is not enough to cause any damage in any aluminum parts we find in aircraft engines. I don't care if he used ice water and dunked it. Until you can prove other wise get a grip.
 
Tom-D said:
you, like many, have missed the point again. A drop temp from under 300 degrees to ambient is not enough to cause any damage in any aluminum parts we find in aircraft engines. I don't care if he used ice water and dunked it. Until you can prove other wise get a grip.
Click to expand...

I'll let science know they're wrong. In the mean time you can look up the linear expansion formula and do the calculations yourself. I hear rapid change is good for metals we depend on
 
gitmo234 said:
I'll let science know they're wrong. In the mean time you can look up the linear expansion formula and do the calculations yourself. I hear rapid change is good for metals we depend on
Click to expand...
show me. or quit.
 
I'm looking forward to this calculation... Plug in 230 F cylinder temperature and 75 F for the water. According to my calculations we will get 1/1000" change in dimensions of cylinder. Horrifying!!!! Oh and that is assuming it is dunked in water. In this case it is not. The water is a spray getting heated up as it travels into the cowling and then only gets maybe a 5% coverage. So I'm going to go with an even smaller change in dimensions. Maybe a 1/10000" contraction. Ooh the horror!

I'm going to tell my CFI to keep sucking that egg.
 
gitmo234 said:
Please go on and tell me the make and model of my car since cast iron engines began being phased out in the early 90s and aluminum started becoming more popular. The likely hood of cracking depends on the metal as much as thermal difference
Click to expand...

Yup, even older performance cars and bikes have been using aluminum as standard issue for some time.
 
rolivi said:
I'm sure I'm being overly curious.. but... the engine in a VW Bus is in the BACK and the picture showed a VW Bus that was partially submerged in the FRONT.
Click to expand...

Funny how this works.. You see that VW bus is going forward as is evidenced by the splashing of the water. Usually when a rigid object such as a bus moves forward, eventually the rear end will be where the forward end is. So at some point further along, that rear of that VW bus will be where you see the front at the moment. In the water. Submerged. That poor, poor engine.

Shock cooling is a horrible thing and very real. Be afraid everyone.
 
Horse said:
I'm looking forward to this calculation... Plug in 230 F cylinder temperature and 75 F for the water. According to my calculations we will get 1/1000" change in dimensions of cylinder. Horrifying!!!! Oh and that is assuming it is dunked in water. In this case it is not. The water is a spray getting heated up as it travels into the cowling and then only gets maybe a 5% coverage. So I'm going to go with an even smaller change in dimensions. Maybe a 1/10000" contraction. Ooh the horror!

I'm going to tell my CFI to keep sucking that egg.
Click to expand...
Show your math, that doesn't sound right.
 
PaulS said:
Show your math, that doesn't sound right.
Click to expand...


Thanks for that, you're right, I messed up. It is even less than that. There is no way the exterior of that cylinder was still 230 F after that amount of time.
 
Horse said:
Thanks for that, you're right, I messed up. It is even less than that. There is no way the exterior of that cylinder was still 230 F after that amount of time.
Click to expand...

Still wrong, show your work and we'll figure out where you messed up, maths is hard.
 
Photoshop that to say "A pilot called Horse" and I might just have to steal it. :D
 
Horse said:
Funny how this works.. You see that VW bus is going forward as is evidenced by the splashing of the water. Usually when a rigid object such as a bus moves forward, eventually the rear end will be where the forward end is. So at some point further along, that rear of that VW bus will be where you see the front at the moment. In the water. Submerged. That poor, poor engine.

Shock cooling is a horrible thing and very real. Be afraid everyone.
Click to expand...

That poor engine is still producing heat.same reason vehicles can run in Antarctica. The key here is the sudden change. You should also re-check the temperature of your water. Then again, like I said, go ahead and run your car and spray down the block every time you're done. I'm sure you're experienced enough to know it will be fine.
 
Horse said:
Thanks for that, you're right, I messed up. It is even less than that. There is no way the exterior of that cylinder was still 230 F after that amount of time.
Click to expand...
While both the car and airplane engine start at ambient temperature, the auto engine temperature tops out not far above 200° F, while the aircraft engine temperature closes in on 500° F. http://www.flyingmag.com/safety/maintenance/piston-engine-essentials Engine temperatures increase after shutdown. And, what was the OAT that day? On a hot day we have to wait 5 hours before we can borecsope some engines when we normally wait 3, due to equipment temperature restrictions.
 
Last edited:
gitmo234 said:
That poor engine is still producing heat.same reason vehicles can run in Antarctica. The key here is the sudden change. You should also re-check the temperature of your water. Then again, like I said, go ahead and run your car and spray down the block every time you're done. I'm sure you're experienced enough to know it will be fine.
Click to expand...
Have you ever seen how fast an turbocharged TSIO 540 cools when the outside air-temps are -40?
Part 135 operators operate these engines day in and day out cycle after cycle, with no problems. You pull power on a Navajo Chieftain and the CHTs will go down faster than the gauge can keep up.. Shock Cooling at it best, and never a problem of cracking.

Yet folks here believe one time from less than 300 degrees has done damage. Some one needs to get real.
 
James331 said:
Yup, even older performance cars and bikes have been using aluminum as standard issue for some time.
Click to expand...
Ya think?? just because the aluminum is lighter and has a better thermal expansion rate much better than cast iron? no can't be :)
 
You must log in or register to reply here.
Back
Top