KX500 water pump modification

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Sandblaster
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Re: KX500 water pump modification

Post by Sandblaster »

All valid points which is why I think Motorrad is reluctant to try it.
Then again, If the head is running significantly cooler, perhaps it would make the cylinder cooler as well even if the water temp is warmer then it would normally be going into the cylinder.
I sure wish Larry would reply to Motorrad's question.
If he has tried it and has some numbers I'd sure like to know what they are.
Then again it may be a trade secret :shock:
If bikes are for kids I'll never grow up.
Qsixteen
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Re: KX500 water pump modification

Post by Qsixteen »

There are high output 2 cycle engines that come from factory with cooling into head first for many years now. It all about pressue.
Motorrad
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Re: KX500 water pump modification

Post by Motorrad »

Qsixteen wrote:There are high output 2 cycle engines that come from factory with cooling into head first for many years now. It all about pressue.
Image



yes. its crap like dropping stuff like larry did (I did all this 25 years ago)... and not responding further or giving any ACTUALL information. that pisses me off about forums. its like... DUDE if you know somthing, share... if you dont want to share... shut the F up... there are certain "secrets" I dont talk about on the forum... because I dont wish to share them... so I jsut dont even bring them up, as its a Jack ass move to brag you know somthing, and wont even share, ... but if ya talk to me in person.. and I like you... yea.. its all free game...


sorry.. rant over.


no offence to you larry. if you read this.. just using that as an example of MANY MANY other instances with others.
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Friar-Tuck
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Re: KX500 water pump modification

Post by Friar-Tuck »

Hmmm,
There is a direct correlation between heat and pressure, the higher pressure you can maintain the higher temperature you can reach.
Like all the way up into the superheated steam stuff. The temperature will rise, it will just keep the coolant from boiling, up to a certain temperature of course. You can easily get over 300Deg with higher pressures, however your oil will fail.
I don't understand how higher pressure will help keep the engine cooler....Are you talking about (head) Line pressure from the waterpump?
What am I missing here?
Tuck\o/
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Re: KX500 water pump modification

Post by Sandblaster »

Good point Tuck.
Hopefully we can get some clarification :)
If bikes are for kids I'll never grow up.
Qsixteen
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Re: KX500 water pump modification

Post by Qsixteen »

Hot spot gasification in cooling jackets are a result to pump discharge and static pressue. Higher pressue in cylinder and head results in higher degree in boundary layer scrubbing. The higher the water vapor pressue in the cooling jacket the better temperature transfer from aluminum to water. Most stock system produce 3-6psi pump pressue by the time it gets back to pump the liquid is no longer compressed, air bubbles. At lower pressue coming out of pump most air bubbles are not compressed. Now if you static fill you system to 25psi. There are many types of caviation in a cooling system.
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Re: KX500 water pump modification

Post by Friar-Tuck »

Yes, Q this is true. So, your saying the components should be working more efficiently with a pressurized system.
Gosh, the cost incurred to modify the system on a dirt bike to handle the kind of pressures would seem prohibitive.
But I have certainly been wrong before!
Let's see ...If you would run at 25psi, your coolant could reach about 240deg F before boiling.
(That's just Plain Water. I'm sure you could reach higher temps with "coolant" and or additives.) That will leave you with about a 60 deg. F buffer before
your oil would start to go south. Yikes, too close for my comfort level!
All interesting stuff, if I only had the Sheckles to experiment with! Oh well...
My bike has never had a big problem with losing coolant or overheating. I did put a recovery bottle on it. But hey, if you ride like an old lady you don't worry much about it anyway :lol:

I think you have done a swell job improving on what you have to work with so far SB. I am interested in what kind of results you have when you run the bike. I will be using your research on my bike as soon as my current situation gets settled.
Just to throw another variable in the mix, I wonder how much ceramic coating the head and piston crown is worth? Maybe another thread!
Thanks for the interesting conversation and the practical improvements "You Can Do At Home" SB :D
Keep up the good work!
Tuck\o/


http://www.engineeringtoolbox.com/boili ... d_926.html
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Re: KX500 water pump modification

Post by Sandblaster »

Thanks Tuck.
I need to go for a ride soon to get a base line for current temps.
Once that is done I'll install some of the mods and see what happens :)
With Motorrads numbers we should be able to get some solid data put together.
If bikes are for kids I'll never grow up.
Qsixteen
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Re: KX500 water pump modification

Post by Qsixteen »

25psi would include 14.7 atmosphere pressure. Add 6-10 psi to cold system. Your stock system can handle that. Not 14.7+25. Mike that is the best way to test start with stock parts and add one part or mod at a time. Do you have a tt gauge.
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Re: KX500 water pump modification

Post by Sandblaster »

I don't even know what a TT Gauge is :)
Can you clarify what it is?
I was going to use a spark plug temp gauge as that is what other numbers have been recorded using.
If bikes are for kids I'll never grow up.
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