KZScott
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posted April 05, 2009 12:45 AM
more efficient head cooling
this question has been bugging me, so i thought i would see what you guys thought. as we know, water temps actually drop on high speed runs, but cylinder head temps rise at the same time (usually from nitrous or a monster moter ect). this leads me to believe that the head is not transfering enough heat to the coolant, and if we could make it do so, the motor would run cooler(good for those of us pushing the limits).
so... any ideas as to how you could make the head more efficient cooling wise? we upgrade everything else 
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01 ZX-12R 8.84 @ 156.3 no bars, DOT tires. Pump Gas, NA.... turbo 8.47 @ 164.
00 ZX-12R 8.62 @ 165.2 no bars, slicks, Pump Gas, 55 shot.... turbo 8.32 @173
00 ZX-12R Fastest NA Kawasaki in the world 1: 222.046 1.5: 226.390 Loring AFB
00 ZX-12R street turbo 1: 227.9 1.5: 234.1 Loring AFB
00 ZX-12R LSR turbo 1: 263.1 1.5: 266.5 Loring AFB Worlds fastest ZX-12R
CMG Racing RCC Turbos
  
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tcchin
Zone Head
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posted April 05, 2009 06:45 AM
 Edited By: tcchin on 5 Apr 2009 14:46
Use a KX500 radiator cap to increase the pressure of the cooling system to 1.6 bar, which will reduce boiling in the head and increase heat transfer. In cases where local thermal gradients are extreme, the use of straight propylene glycol as a coolant, which has a lower heat capacity than water but has a boiling point at STP near 270F, can increase cooling efficiency by reducing boiling/cavitation even further. Check your local rulebooks, as well as the condition of your cooling system components, before using either of these approaches.
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KZScott
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posted April 05, 2009 09:50 AM
Ill look into it! thx Tim!
____________
01 ZX-12R 8.84 @ 156.3 no bars, DOT tires. Pump Gas, NA.... turbo 8.47 @ 164.
00 ZX-12R 8.62 @ 165.2 no bars, slicks, Pump Gas, 55 shot.... turbo 8.32 @173
00 ZX-12R Fastest NA Kawasaki in the world 1: 222.046 1.5: 226.390 Loring AFB
00 ZX-12R street turbo 1: 227.9 1.5: 234.1 Loring AFB
00 ZX-12R LSR turbo 1: 263.1 1.5: 266.5 Loring AFB Worlds fastest ZX-12R
CMG Racing RCC Turbos
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TRNorBRN6001
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Posts: 2021
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posted April 06, 2009 01:23 PM
Yep, Schnitz sells them repackaged 1.6Bar caps. Just spray more N2O at the Head! lol
Just kidding ya KZ.
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TFA 200MPH CLUB MEMBER!
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krexken
Zone Head
Posts: 732
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posted April 08, 2009 08:30 PM
How about a reflective coating on the combustion chamber and valves so it doesn't soak up as much heat to begin with. Shove the heat out the exhaust. It should also make the engine more efficient also. Also the water pump may be moving the water too fast to effectively remove the heat. You could try removing the thermostat and experiment with different size orifices. Maybe.
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KZScott
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posted April 08, 2009 08:41 PM
keeping the head cooler with coatings may lead to more heat being transfered to the exhaust valves tho right? (not something i want to try with nitrous)
the coolant is plenty cool as it comes into the head from the rad(temp goes down as speed goes up) maybe more flow would help. coolant may be wasting time in the rad at speed? you would really need to monitor oil temp to see if it was effective though eh?
____________
01 ZX-12R 8.84 @ 156.3 no bars, DOT tires. Pump Gas, NA.... turbo 8.47 @ 164.
00 ZX-12R 8.62 @ 165.2 no bars, slicks, Pump Gas, 55 shot.... turbo 8.32 @173
00 ZX-12R Fastest NA Kawasaki in the world 1: 222.046 1.5: 226.390 Loring AFB
00 ZX-12R street turbo 1: 227.9 1.5: 234.1 Loring AFB
00 ZX-12R LSR turbo 1: 263.1 1.5: 266.5 Loring AFB Worlds fastest ZX-12R
CMG Racing RCC Turbos
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dougmeyer
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posted April 08, 2009 08:55 PM
So, where exactly is that data (head temps higher, coolant temps lower) coming from?
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It's not that I think you're dumb, it's just that so much of what you know isn't true....
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Bawls
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posted April 09, 2009 07:07 AM
Edited By: Bawls on 9 Apr 2009 15:10
Run Methanol lol It was good for about a 40% HP increase on 4-stroke quads and the cylinder head would frost over. I don't know how well it would work with EFI since it burns twice as fast, but would be interesting to see. (the downside is that it isn't very nitrous friendly)
____________
Best 60ft: 1.42
Best 1/8th: 5.97
Best 1/8th MPH: 119
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dougmeyer
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posted April 09, 2009 06:50 PM
Bawis,
Nobody asked me, but we try and keep things accurate around here. I know you were just throwing in a comment for a joke, but ......
Methanol burns slower than gasoline, not faster. This is why you need to (and can) run much more ignition advance on alcohol. Also, alky does not automatically increase hp. It contains it's own oxygen, but you need to run about twice as much alky to get the same hp as gas (which is why you needed such large jets), and would need double the size of injectors. What you do get is marginally more torque on an equal set up. The torque goes up because of the longer burn time and thye denser mixture due to the vaporization cooling. So, if you can run the same RPM on the alcohol as the gas, you'll get more slightly more HP because the torque is slightly greater.
The head and manifolds frost over because of the rapid vaporization of the alcohol which causes a temperature drop.
Personally I love alcohol engines. They are forgiving, easy on parts and deliver a nice linear power. Lot's of maintenance, though
Doug
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It's not that I think you're dumb, it's just that so much of what you know isn't true....
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KZScott
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posted April 09, 2009 09:05 PM
quote:
So, where exactly is that data (head temps higher, coolant temps lower) coming from?
coolant temp gauge reads lower at high speed.
i havent measured head temps, but i assumed running a fair amount of nitrous would heat things up(it changed the colour of my pipes anyway when i started spraying the bike).
____________
01 ZX-12R 8.84 @ 156.3 no bars, DOT tires. Pump Gas, NA.... turbo 8.47 @ 164.
00 ZX-12R 8.62 @ 165.2 no bars, slicks, Pump Gas, 55 shot.... turbo 8.32 @173
00 ZX-12R Fastest NA Kawasaki in the world 1: 222.046 1.5: 226.390 Loring AFB
00 ZX-12R street turbo 1: 227.9 1.5: 234.1 Loring AFB
00 ZX-12R LSR turbo 1: 263.1 1.5: 266.5 Loring AFB Worlds fastest ZX-12R
CMG Racing RCC Turbos
|
dougmeyer
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posted April 10, 2009 08:24 AM
Where is the coolant temp sensor? Before or after the radiator? If it is before- well, it is what it is. Virtually all of the heating of the coolant occurs in the head. Thus, if the coolant temp as it exits the head is lower, it would be fair to surmise that there is less heat going into it from the head-no worries. If the temp is lower exiting the radiator, this is a harder assumption to make because what you are really measuring is the effectiveness of the radiator at high airflows, not so much how much heat is going into it. To really nail this you'd need multiple data points (sensors). When doing engine development we might measure coolant temps at as many as 8 places......
Be careful to draw a hard line between EGT and CHT. They usually follow the same trend, but (especially with N20) you can kill an engine dead way before you see any change in the coolant temp.
Doug
____________
It's not that I think you're dumb, it's just that so much of what you know isn't true....
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tcchin
Zone Head
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posted April 10, 2009 10:10 AM
Edited By: tcchin on 10 Apr 2009 18:13
Just because the coolant temp exiting the head is lower doesn't mean that there's less heat energy going into the coolant. Convective heat transfer is proportional to the temp difference between the coolant and the head, as well as the velocity of the coolant passing over the head. As the engine speed increases, so does the velocity of the coolant in the head. Just because the energy increase per unit area of coolant goes down (temp sensors sample in 2D and don't take into account velocity/volume) doesn't mean that the heat energy transfer per unit time or volume decreases. All this means is that the radiator has more capacity to shed heat energy than the motor has to transfer it into the coolant. If the coolant temp rises with engine speed, then your radiator is probably too small. Also, if the coolant temp sensor is mounted in the head, and since aluminum is a pretty good thermal conductor, it's probably fairly safe to assume that the coolant temp is a reasonable indicator of overall head temp, but not combustion chamber or exhaust gas temp.
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ZRXDean
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posted April 10, 2009 10:16 AM
I love this board.
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Bawls
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posted April 10, 2009 05:46 PM
quote:
Bawis,
Nobody asked me, but we try and keep things accurate around here. I know you were just throwing in a comment for a joke, but ......
Methanol burns slower than gasoline, not faster. This is why you need to (and can) run much more ignition advance on alcohol. Also, alky does not automatically increase hp. It contains it's own oxygen, but you need to run about twice as much alky to get the same hp as gas (which is why you needed such large jets), and would need double the size of injectors. What you do get is marginally more torque on an equal set up. The torque goes up because of the longer burn time and thye denser mixture due to the vaporization cooling. So, if you can run the same RPM on the alcohol as the gas, you'll get more slightly more HP because the torque is slightly greater.
The head and manifolds frost over because of the rapid vaporization of the alcohol which causes a temperature drop.
Personally I love alcohol engines. They are forgiving, easy on parts and deliver a nice linear power. Lot's of maintenance, though
Doug
thank you for correcting my "burns twice as fast" comment. I guess I never fully grasped the full reason why it was making more power when we were building quads. What I do know is that you can take a. Ds650 with a ron woods pipe and tm45 carb on gas that makes 48hp, rejet for alky and it will put down damn near 70hp same dyno, same day. It will also pick up 4 tenths in the 300ft sand drags. I always assumed that it was able to burn twice as fast since you use twice as much for the same given amount of time/ distance. You are correct about it being a pain in the ass maintenance wise. I used to hate purging gas all the damn time.
____________
Best 60ft: 1.42
Best 1/8th: 5.97
Best 1/8th MPH: 119
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whitehendrix
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posted April 10, 2009 06:18 PM
Tim, i am completely confident that you're either 80 years old and have been an engineer since birth or do indeed have a wifi hooked up to your brain with multiple tabs opened.. or you're just merely not human. you're a superior species from another galaxy.
awesome info in this thread. carry on.. lol
oh.. maybe another bit of thought from me?
we've established the cooling effect rising linearly with airflow thru the rad core, minus al lthe variables such as heat transferring potential, velocity, density, pressure, boiling point, contact area for in the head, ect.
i have yet to see the mentioning of just ambient air flowing over the motor itself.. box that thing up and rely solely on the oil cooler and radiator, and chances are your temps will be at least a tiny bit higher.. makes me wonder if a naked bike runs cooler than a full-fairing bike.. probably does, actually!!
so, obviously, with higher flows thru the rad core, so is the transfer of heat to ambient thru airflow over the motor itself.. another reason i think why real-world runs net more WHP than whats realized even thru correction factors on a dyno.
theres SOO many variables tho, it's mind numbing.
____________
Duct tape is the handyman's secret
weapon. The black is for formal
occasions. - ZRXDean
ill never own a busa unless
someone gives me one.... and then
ill sell it -KZScott
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tcchin
Zone Head
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posted April 10, 2009 07:38 PM
WH - With the four kids (7, 5, 3 & NB), the day job, the race team, the Flowmaster development deal and our own racing product line in the works, I'm burning the candle at both ends and in the middle and closing in on 80 faster than the calendar would normally allow! Fortunately, this forum is one of the few places I can purge my engineering blueballs, mixed metaphor notwithstanding. Sure, there's engineering in racing, but we only race once or twice a month. And we're only doing R&D on our new products, with the rest of the time being production engineering (boring). And the day job (sys admin) is far from engineering, but it keeps the fud on the table. Glad you enjoy the technical babble, as well as the occasional DPGB comment.
As for a naked bike cooling more efficiently than a fully-faired bike, I have to disagree. The fairings are designed to direct the air to the places that need cooling that aren't necessarily in the free airlow and to keep the hot air off the rider. We instrumented a couple of bikes about 10 years ago and found that the crude ducting that bikes of that era had still provided considerable enhancement to the radiator/oil cooler in terms of keeping the engine and voltage regulator cool. Remember that goofy NACA duct that's scabbed onto the side of a 94-97 VFR? It's not just ugly, it's essential! Remember those big air ducts that dump air onto the sparkplugs of an FJ1200? The bike will detonate like crazy in city traffic without them. CBR600F's will cook off a regulator in 5000 highway miles without the stock fairings.
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whitehendrix
Zone Head
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posted April 10, 2009 08:20 PM
Hmm.. very interesting.. i love the DPGB stuff and the technodrivel.
it's just astounding to me how no matter what it is, you have the perfect explaination for it, and typically verge on the point of me not knowing what the hell you're saying either with your vocabulary and delivery, or the utter technical levels you approach..
i kinda figured as much as far as heat Vs rider but didn't put as much emphasis on it as maybe i should have.. you bring some good points and stuff i didn't really consider, like the detonation on the FJ. i'f seen F4i stuntbikes murder regulators.. so i recall that not and guess it goes hand in hand with slow speeds and no fairings.
i always thought that there was an added effect on cooling thru just radiated heat not related to the cooling system, but i'll take your word for it.. if this was any other forum, i'd probably be debating this, but between you, Jim, Karl, Doug and Scott, i will just shut up and listen..lol
very intersting tho.. really is.. considering i've been assuming for years, without any real evience (then again never thinking about it until now, nor discussing it) but i've always sorta wondered like on my 7-R about that little diffuser panel under where the kleen air solenoid was.... always wondered if there was an added benefit to that panels removal, or if it was there by sheer design.. perhaps influencing or influenced by a low-pressure spot to remedy overheating on another area of the bike.
thank you tho for a little background on ya!! i like knowing where people get their ridiculous amounts of info from and whether they're credible.. i have known pretty much from day 1 who was credible here and who could be labled a "monosynaptic twat" or whatnot..lmao
i wanted to get a mech. engineering degree after getting my electrical.. then i saw what it costs.. kinda killed that immediately.
____________
Duct tape is the handyman's secret
weapon. The black is for formal
occasions. - ZRXDean
ill never own a busa unless
someone gives me one.... and then
ill sell it -KZScott
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KZScott
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posted April 12, 2009 07:19 PM
quote:
I love this board.
i could have skipped HS and the semester of mechanical engineering i took and if i had of put half the time that took into reading BL, i would be a smarter guy.
Tim and Doug never cease to amaze me
now that i have a bit of a better understanding of this, i have a question about the fairing design directing air flow. is the main purpose of the ram air covers on my 12 designed to protect the drivers hands from heat (and look nice) or is the main reason to direct airflow to the back of the motor? i noticed with the bike running(on a stand) and with no ram air covers, the hot air from the fan gets blown up at the bars. not just some, a lot of hot air. too hot to keep your hands there with no gloves hot. at speed, is this hot air "diluted" and actually cooling the back of the motor?
i guess ill focus less on coolant temps, i just thought there may be gains to be had, but its a little too demanding to get the kind of data i would need.
the good news is i bought a used LMA-3(in the mail) so i can log EGT (from one cylinder anyway)
____________
01 ZX-12R 8.84 @ 156.3 no bars, DOT tires. Pump Gas, NA.... turbo 8.47 @ 164.
00 ZX-12R 8.62 @ 165.2 no bars, slicks, Pump Gas, 55 shot.... turbo 8.32 @173
00 ZX-12R Fastest NA Kawasaki in the world 1: 222.046 1.5: 226.390 Loring AFB
00 ZX-12R street turbo 1: 227.9 1.5: 234.1 Loring AFB
00 ZX-12R LSR turbo 1: 263.1 1.5: 266.5 Loring AFB Worlds fastest ZX-12R
CMG Racing RCC Turbos
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dougmeyer
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posted April 12, 2009 07:37 PM
The hardest thing about designing a cooling system that uses a liquid to air radiator is not getting the air into the radiator, it's getting it out. Generally speaking, there is an easy way to get an area of positive air pressure on the radiator face. But getting that air efficiently through and out the back, ideally into an area of lower pressure, is often overlooked. On your 12 those exit ducts on the fairing sides accomplish this nicely, and I believe your observation about the covers at the fairing/frame interface is accurate. They are not critical, but are part of a well designed system of air management.
Remember this; when a group of engineers as good as the ones at Kawasaki, (and especially Kawasaki) design something, almost everything is the way it is for a very good reason. At KMC, engineering leads, styling follows.
Doug
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It's not that I think you're dumb, it's just that so much of what you know isn't true....
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KZScott
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posted April 12, 2009 08:16 PM
Doug, do you think a shroud would benifit the 12 or is it designed to work more with wind than the fan?
____________
01 ZX-12R 8.84 @ 156.3 no bars, DOT tires. Pump Gas, NA.... turbo 8.47 @ 164.
00 ZX-12R 8.62 @ 165.2 no bars, slicks, Pump Gas, 55 shot.... turbo 8.32 @173
00 ZX-12R Fastest NA Kawasaki in the world 1: 222.046 1.5: 226.390 Loring AFB
00 ZX-12R street turbo 1: 227.9 1.5: 234.1 Loring AFB
00 ZX-12R LSR turbo 1: 263.1 1.5: 266.5 Loring AFB Worlds fastest ZX-12R
CMG Racing RCC Turbos
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dougmeyer
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posted April 12, 2009 08:48 PM
Please explain.... Shroud?
Remember the fan is there only to create airflow when there isn't enough from road speed.
____________
It's not that I think you're dumb, it's just that so much of what you know isn't true....
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KZScott
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posted April 13, 2009 06:33 AM
ok, its kinda apples to oranges, but my uncles chevelle (502ci) would over heat untill he had a custom aluminum shroud made so that the fans had to pull the air thru the rad vs some thru, and some around. now that i think about it more, i believe he was fine untill he slowed down
____________
01 ZX-12R 8.84 @ 156.3 no bars, DOT tires. Pump Gas, NA.... turbo 8.47 @ 164.
00 ZX-12R 8.62 @ 165.2 no bars, slicks, Pump Gas, 55 shot.... turbo 8.32 @173
00 ZX-12R Fastest NA Kawasaki in the world 1: 222.046 1.5: 226.390 Loring AFB
00 ZX-12R street turbo 1: 227.9 1.5: 234.1 Loring AFB
00 ZX-12R LSR turbo 1: 263.1 1.5: 266.5 Loring AFB Worlds fastest ZX-12R
CMG Racing RCC Turbos
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gs11ezrydr
Novice Class
Posts: 34
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posted April 20, 2009 03:05 AM
With all the talk of porting and polishing of cyl. heads .I was wondering is it possible to port your cooling system .In order to increase volume and therefore absorption of heat. If so is there a point where it runs to cool to produce good horsepower.Curious!!
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rgeorge
Expert Class
Posts: 220
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posted April 20, 2009 09:37 AM
quote:
With all the talk of porting and polishing of cyl. heads .I was wondering is it possible to port your cooling system .In order to increase volume and therefore absorption of heat. If so is there a point where it runs to cool to produce good horsepower.Curious!!
Not a good idea. The rough cast finish on the outside of the cyl walls has a higher surface area than a smooth finish. If you take out the bumps the heat transfer will decrease.
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dubious
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Needs more time to ride!
Posts: 8442
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posted April 26, 2009 12:24 PM
I have radiused the edges and smotthed the volutes without comprimising the volume / velocity on centrifugal pumps, and had great success doing so with the coolant pump on my dirt bikes.
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destiny will overcome intervention.
Some are not worthy of the effort.
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