increasing klr 650 fan cfm plus coverage

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Jeff Saline
Posts: 2246
Joined: Fri Oct 10, 2003 6:02 pm

fan switch

Post by Jeff Saline » Mon Jul 02, 2007 11:52 pm

On Mon, 02 Jul 2007 16:14:04 -0400 Zachariah Mully writes:
> On Mon, 2007-07-02 at 13:02 -0700, Craig Kahler wrote: > > Just tryng not to deviate too far from stock. I can't help but > think > > Kawasaki had some reason for using a 160F thermostat, or am I > giving > > them too much credit? I'm tring to stop the drastic temp. swings. > > While crusing my temp gage reads about 15%. in stop and go traffic > it > > gos to about 80% of full range. As it is now, I'm not sure this > thing > > is much better than an air cooled bike. Correct me wrong, but as > I > > understad it, we now have a 160F/205F thermostat/ fan switch. I > would > > like to close that gap and not have those temp swings. It's the > reason > > I bought a water cooled bike. If I go to a 195-205F t-stat I can > see > > there may be no need to mess with the fan switch, But I have > concerns > > of engine problems/boiling gas/rider comfort, runing the engine > that > > hot. I am not a professional mechanic, just a tinkerer who like > to > > "improve" everything I get my hands on. So if my concerns are > > unfounded, let me know. > > Craig Kahler > > > Again, every one is frantic about temperatures, but no one has any > hard > data. You're all relying on a $0.04 temperature gauge that is made > from > old Voltrons and parts that Harleys have shed, and is about as > accurate > as the CIA intelligence about WMDs. Get an IR thermometer ($10) and > measure the goddamn engine temperature before you all go get your > panties in an obsessive compulsive bunch and make a $200 engine > coolant > bypass switch. > > Want the easy fix? Put a piece of blacktape over the temperature > display. Stop obsessing over a non-problem and go riding. > > Z
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Zach, Pretty nasty reply you've posted to everyone. I didn't like it but I'm gonna reply since I think you've sent Craig some incorrect information. Bill Watson has done plenty of testing of the KLR cooling system. And he's shared his data with the world. And taken the time to do some very nice write ups and explanations that most folks can understand if they make the effort to digest it. I can tell you not everyone is frantic about temperatures. I've talked with plenty of guys about the 195 degree stat housing and by pass I made and many don't see any need for it. Others would like to address the large temperature swings in engine coolant temperature caused by the stat opening and closing. I'll suggest to you that an IR temperature indicator will not (as a rule) accurately indicate coolant temperature or engine temperature. It'll tell you the surface temperature of the part you are focused on but that won't tell much of a story unless you really know how to interpret the information. From what I've seen the temperature gauges are accurate enough to give the rider some useful information. They may be off a few degrees but give consistent indications. Knowing the temperature sender is in the head and has sometimes stagnant coolant around can allow a guy to make a more educated guess as to what's really happening with the engine temperature. Just as a for instance... A few weeks ago on my return from the Hole in the Wall my temperature gauge was indicating the engine was overheating. And it was. I had a very strong tail wind and since I was riding on a dirt road my speed and the wind speed were close to the same. Even with my fan override switch trying to make some air move over the radiator the engine temp didn't lower. When it got to 240 I finally pulled over and let it cool off a bit. I did cycle the engine a few times to move cooler coolant through the engine coolant passages. When it was back to about 180 degrees I started riding again. After another few miles the temps was even hotter and I let it get up to over 260 degrees before stopping. I knew the sender was only indicating a "hot" spot in the head. But this time I turned the bike around into the wind. Again a few cycles of the engine to circulate coolant and the readings were back to less than 195. I got on pavement a few miles later and didn't have the tailwind for a bit. But even when I had the tail wind I was traveling about 60 mph and that was enough to keep the engine in the "normal for my bike range." For those wondering... at speeds above about 40 mph my bike tends to run at a steady 195 degrees up until about 75 degrees ambient temperature. Then the coolant temp rises about equally with the ambient temperature rise. So when I'm running in 100 degree temps my engine temp is gonna run about 220-225 degrees. That's normal on my bike. And when I'm running at 22 degrees my engine temp is gonna run 195 degrees. With the stock stat, at 22 degrees I'm lucky if my engine temp gets to 160 degrees. For Craig... I think the way you can stop the large temperature swings is to install a hotter stat and a by pass. This will help the most in cooler temperatures. Once you get into hot temps the bike is really under cooled and the stat is opened about all the time anyway. Plenty of folks have bikes with high miles and never have had an issue with the stock cooling system. But... running the engine a bit warmer that the stock system allows will probably add to engine life over the long haul. For Doug... Norm mentioned I've been planning on adding a second radiator to the KLR cooling system. The 195 degree stat has addressed cooler weather running. I think the second radiator will address warmer weather running. Once the stat is open the stock KLR cooling system just doesn't have enough surface area to address the heat transfer of the hot coolant. I think the right radiator from a KLR250 mounted where the stock KLR650 coolant tank is located will address this issue. If I recall correctly as I'm not looking up my notes from last year, the KLR205 right radiator will increase cooling area about 50%. Then I'm thinking a guy will have the best of both worlds for cool and hot ambient temps. I think it's a good idea but haven't gotten around to doing it yet. Best, Jeff Saline ABC # 4412 South Dakota Airmarshal Airheads Beemer Club www.airheads.org The Beautiful Black Hills of South Dakota 75 R90/6, 03 KLR650, 79 R100RT
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