Checkvalve failure

[raddy]

Hi
I just found problem in my coolingmist system.....Few weeks ago I noticed drop in water level, car was not driven at this time, so water just dissapear from tank.....I start to checking all fittings, pump etc, but no signs of water leak.....Just note, I have 2 nozzle setup (before turbo, before TB) both nozzles have brass checkvalves (supplied by coolingmist) in their lines....I was really nervous about water missing, but just last thing that I checked was right one.....I disconnect inlet turbo hose and 1/2 litre of water comes out of it :shock: :? :mad:
Yes, checkvalve for pre turbo nozzle (located below in relation to tank) was stuck open......and water slowly siphoned through pump and nozzle into hose and turbo. Yes, turbo (compresor housing) was flooded with water.
I removed this checkvalve to confirm that it is stuck open. Put thin screwdriver in it and push few times against flap inside. It moves normally, no signs of something wrong with/in it. After this it closes perfectly again....Something must was inside, I really dont know. Sure, Im using only distilled water in system.
Put it back, all is normal again. I will add 3rd checkvalve right after pump to prevent this in future. And yes, turbocharger last it, it working fine (no blade damage, no axis movement), just some water comes to oil, but after long run without any WI it comes out through breather.

Did you ever meet with similar failure?

[JohnA]

Yes, I had mine stuck shut.
No reason why, maybe there was interaction with methanol, who knows....

The system had been inactive for 2-3 months, as I took it from the previous car and had it stored to be used in the next one. Now I assume nothing, everything is treated as a potential failure point!

[raddy]

Hi
Im back with serious problems with pistons, just to confirm that it wasnt caused by water/ethanol injection.
5000km ago I get damaged pistons. They was damaged in strange way, no damage at all at the top of the piston or top edge, but complete destroyed between the rings. Engine was rebuilded. Now I have same damage. It looks very strange for me. Garage told me that reason is too high compression/boost pressure caused melting piston. But this should leave clear signs on the top of the piston, isnt it?
Anyway, here are pictures:

top of the piston, no visible damage (4 dots are marks for No. of piston)
http://www.ukazto.com/?img=P101000x.jpg

side of the piston, damage
http://www.ukazto.com/?img=P1010004-wxy1.jpg

Edit: just note that top comp. ring is undamaged.

Thanks for your advice.

[keithmac]

That`s very strange!, I suppose high compression could be a factor, definitely no signs of detonation. What piston is it (forged?). Is the conrod still true?.

[raddy]

this should be explanation, page 36
http://www.cabletiemotorsport.com/Pistons.pdf


I must also note that damage at all pistons was only at exhaust side. The true is that I probably too much advanced ignition after WI installations. As I never hear detonations, with WI a feeled safe. But not all dets can be audible.....
It wasnt forgeds, just standart pistons.

[keithmac]

What advance/boost were you running?. Cheers for the link some good reading there!.

[raddy]

I was running with 1.3bar of boost. And timing should be 25deg, if using formula timing map value-16. Thats with 98octane fuel and water injection, pre and post turbo. Maybe WI can be explanation why I didnt heard typical knock sound....

[Richard L]

Wouldn't be possible to install a solenoid valve inline, they have much stronger springs and does not caase as much pressure drop at the checkvalve.

How old is your checkvalve?

[raddy]

Hi Richard

In meantime I add 3rd checkvalve just after pump (before dividing water line to pre comp and pre TB), so in case of same failure of one checkvalve it will be secured by this 3rd one....Checkvalve which was stuck open was about 1 year old. But after this it never happens again, so Im using it again.
I know that solenoid can be more suitable, but I was preffering mechanical setup at this time, but you are right, maybe I will use solenoid then.

Just a question regarding to pressure drop at checkavalve: can you explain this more deeply please? It mean that if checkvalve have cracking pressure let say 30psi, and pump is 150psi that at nozzle I will have just 120psi pressure?

[Richard L]

Almost all progressive systems use a checkvalve between the pump output and nozzle for the reasons listed below:

Positive effects (well documented):
1. Retain some pressure in the line to compensate the next injection event. A 20psi loaded checkvalve will keep 20 psi of pressure in the line after injection.
2. Stop water being siphoned into the engine if the water jet is installed in the vacuum side of the manifold.
3. Prevent emptying the entire tank into the inlet tract if the tank location is higher than the jet (gravity fed) or the car is parked on an incline.
4. Stop some dribble after an injection event. Even when the power of the pump is switch off, the inertia of the rotating mass keeps the pump running for a second or so.

Negative effects (less well documented):
5. The presence of a checkvalve has a very significant impact of the dynamic range of a 150psi progressive pump speed system. A 20 psi checkvalve inline will instantly drop the 150 PPS system down to a 130psi span.

6. A normal nozzle requires ~30psi for produce a decent atomised spray. An inline 20psi checkvalve means the pump has to produce 50psi to produce a decent spray.

7. Let say the PPS system?s starting point is at 12psi boost, the system will now require 62psi to produce a decent spray. Some vendor will tell you a check valve will not impede flow once it is opened, true. But it will tax the pressure heavily where the PPS system relies heavily upon.

8. When the PPS system arrives at 24psi boost (end point) manifold pressure, the dynamic pressure is now further taxed. Before not too long later the dynamic range of a PPS system is now from 62psi to 126psi ? translate it to flow: 176cc/min to 326cc/min, a mere 84% percent increase.

9. I have taken some data from a reputable PPS system manufacturer, a 150-psi 60W Shurflo flow pump has the follow characteristics:

M2 nozzle with 1/8 ID hose 180psi
M3 nozzle with 1/8 ID hose 160psi
M5 nozzle with 1/8 ID hose 135psi
M14 nozzle with 1/8 ID hose 105psi

From the figures above, the pump is only capable of sustaining 135psi system pressure on a M5 nozzle. Despite claiming the pump is capable of flowing one 3-4 litre per minute, conveniently missing the pressure parameter. The above PPS system maker is the only one that published these figures in public ? thumbs up for them.

Summary:
Some PPS system makers are now offering an inline solenoid upgrade so that the dynamic range is improved by a good margin. Not sure why they didn?t include it in the kit at the beginning. Many PPS systems run their pumps up to 200-300psi - something I have questioned Shurflo, they said NO, NO and NO - no "ifs" or "buts". They are looking into a higher pressure pump but not yet done and will not be released until they are comfortable with it. I have a meeting with the Shurflo's director of engineering at our works two months ago during his UK visit - he confirmed the imaginary 200psi+ pump (8000 series).


Here is an illustration of the above in graphical form:

http://www.aquamist.co.uk/forum/20psi-CV.gif

[dvldoc]

Good post, I have always said that these do not run at 300psi no matter what some kit makers might claim. Here are our new pumps numbers for pressure with a check vavle in place but not installed or under boost.

I will have to disagree with them with saying these cannot hit 200psi at 12v no but these will take up to 15v with no problem.

Test conducted with a snubbed 3" Glycerin-Filled Gauge with NIST Certificate. Keeps things nice and smooth with no guessing on accuarcy.

12-30VDC Power supply at 13.25 volts. All numbers rounded down to the nearest multiple of 5.

M2 230psi
M3 225psi
M4 215psi
M5 190psi
M7 180psi
M10 170psi
M12 Not tested (didnt have one handy here on Guam)
M14 155 psi

Of course you would have to subtract the boost against the head of the nozzle for final figures. Our check valve is 16psi cracking pressure.

[raddy]

oh my god, it did it again :mad: leaked complete tank into turbo, how nice is to see this, Im give up and disconnected pre turbo nozzle. And this time it was with checkvalve in opposite direction (ie allways closed, as I temporary disabled pre turbo nozzle for testing). It look like sealing problem of checkvalve, made me really ugly :twisted:

[Richard L]

Hi Richard

In meantime I add 3rd checkvalve just after pump (before dividing water line to pre comp and pre TB), so in case of same failure of one checkvalve it will be secured by this 3rd one....Checkvalve which was stuck open was about 1 year old. But after this it never happens again, so Im using it again.
I know that solenoid can be more suitable, but I was preffering mechanical setup at this time, but you are right, maybe I will use solenoid then.

Just a question regarding to pressure drop at checkavalve: can you explain this more deeply please? It mean that if checkvalve have cracking pressure let say 30psi, and pump is 150psi that at nozzle I will have just 120psi pressure?

If you add three checkvalves you will loose 3x checkvalve pressure from the line pressure.

Time to use a solenoid valve. What type of checkvalve is it, is it from McMasterCarr?

[raddy]

My last setup was only with 2 checkvalves, as I buy new one in meantime, so bin 3rd checkvalve. All checkvalves was from coolingmist, brass type....Youre right, time for solenoid....

[Richard L]

If you use threecheckvalbe inlien, you wil gert 66psi pressure drop for sure.

See this video lnk:
http://www.aquamist.co.uk/forum/gallery/abner/set1.jpg0

http://www.aquamist.co.uk/forum/gallery/abner/p-cv.html

[raddy]

Hi all
Finally, 3rd checkvalve failed, in this case complete o ring seal just fall out of it...I installed solenoid in meantime, just want to tell other something about quality and safe of these checkvalves...

[Richard L]

Can you post a picture of those checkvalves?

Checkvalve is only as good as the seal and seat being re-aligned properly after opening. Spring rate/orifice ratio is relatively low compared to a solenoid valve.

Which coolingmist system do you have, it is not easy to splice in a solenoid valve electrically.

[raddy]

they are same like you can see here:
http://www.coolingmist.com/detailmain.aspx?pid=QBRCV01

Im sorry but there is nothing to photo at my checkvalve, just internal o ring (seal) felt off of it. Previous checkvalves have som problems with sealing, probably also with rubber o ring. It looks like this o ring is pushed out of it seat after time....

I have basic WI kit (just pump, pressure switch, nozzles), including solenoid into circuit tooks me 5 minutes, really nothing hard about it...Solenoid is acutated directly by switched pump voltage, works fine...

[Richard L]

I was only concern about the solenoid valve connection if you have their varycool system. No probelm with your boost switched system at all.