LC8 water pump upgrade...

Discussion in 'Dakar champion (950/990)' started by tinwelp, Sep 15, 2019.

  1. tinwelp

    tinwelp Professional Idiot

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    Hello people.
    I run a 2006 950SM with FCRs, Arrow pipes, FMF silencers, a touch of porting and a slight compression hike. For more than a few years I've ran the speedo/tacho from a later 990SD and relatively recently I fitted the bodywork and tank from the 990SM... so yes it's a bit modified and despite owning it since 2007, I still love it and will probably keep it in the fold for evermore.

    However it's not perfect, with one of the few remaining issues being a tendency to run quite hot. I qualify this as very frequent operation of the fans (two on the 950SM) when traveling at low speed, a normal operating temperature maybe only three bars from maximum on the speedo, and an almost guaranteed overtemp light if stopping at lights and idling for a minute or so during the summer (30+°C ambient).

    At first I thought there was an temp sensor issue and indeed it turns out the SD instruments use a different sensor, yet swapping it didn't do much. I measured the water temp by thermocouple and noted the fan started at 98°C, went off at 92°C... but crucially, in the reported overheat condition at a stoplight, the water temperature continued to climb, with the warning light coming on at about 105°C. Pants.

    Ok, clearly I've a temp gauge/ sensor/ calibration problem, easy enough to fix with a few resistors, but being unable to grab hold of the ever-climbing water temp when idling isn't so simple. I could richen up the pilot circuit to reduce the generated heat, but I much prefer to run quite lean here to give good fuel economy when pottering about (heap on the abuse if you like, I don't care, but for me that's a huge attraction to the FCRs: excellent economy when you want it, fantastic power when you want it, and as much control as you could wish for in between). Bigger fans? Not easy. Switch on the fans at a lower temp? Maybe, but that relies on the problem being one of thermal inertia... and it isn't. I know because that's what I tried next, fitting an 80°C fan switch. Bugger all difference other than the fans came on earlier and still the temp continued to climb at the stoplights. Double pants.

    Bigger radiator next? Fek. A bold and expensive move. But wait, if the existing one is ok rejecting the 70+kW asked of it when the engine is at full load and speed, and the bike is pushing through the air fast enough to extract the heat, can my issue really be improved with a bigger radiator? If it held a bigger volume of coolant I'd of course increase my thermal inertia... but that's not really the root cause. If it had a bigger cooling area and commensurately bigger fans, yes it'd work... but finding room wouldn't be easy. Another way? What if the coolant flow was higher? Easy enough: turn up the idle speed. Score! Idling at 2500rpm instead of the 'normal' 1400(ish)rpm fixed the problem despite the expected higher heat rejection with the higher engine speed. At this higher idle, maybe 30s after the fans came on, the indicated temperature dropped. Yes please.

    Ok, I need a bigger pump. How to do this? Tripleclamp we're working on one (Hi Alon), but nothing popped out of their development machine and I think the project was cancelled (please correct me if I'm wrong). I was pretty much convinced I was either going to have to add a small electric pump to prop up the flow at idle, or build my own impeller, and of course the latter was preferred for simplicity and reliability... Then, during a moment of boredom, I made a rare visit to Facebook and out of the usual pointlessness popped something about an LC8 water pump kit!!! Eeek! What? Yes please. I got in touch with the author immediately and a few weeks later this is sitting on my bench:

    IMG_1479.JPG IMG_1481.JPG IMG_1482.JPG

    The black part is obviously the OE pump impeller. The spacer plate seems to be water cut, and the impeller may be CNC machined from solid or even cast, but it's all very presentable and well-finished. On the positive side the vanes are considerably taller and the inlet area seems a little larger, so it should shift more water. On the negative side, the vanes aren't profiled to the pump cover so there'll be a considerable drop in efficiency, they look like they'll be quite prone to cavitation and I believe the fluid friction may be quite a bit higher, but what the hell, worth a try.

    The installation video which came with the order confirmation was nothing a few sentences couldn't have conveyed with more efficiency, but installing it really was as simple as you could imagine. It highlighted another minor issue: the spacer plate consumed all of the height of the location dowels in the engine cover leaving nothing to locate the pump cover accurately. Not ideal and although the dowels could probably be pulled out a little to leave enough to catch the cover, it wasn't good enough for me, so I hoiked out the originals and replaced them with dowels 5mm taller. All's good.

    Buttoned up, burped, idled to cycle the fan on and off a few times, re-burped, topped up, cap on, idle set back to 1400rpm and out for a ride.

    Well?

    Erm... yes. Buggered if it wasn't a complete success!

    A hard run followed by stopping and idling for 10 minutes resulted in nothing more than a bit of fan running and the temperature gauge actually dropping! Very cool (groan).

    So, if you've a hot running LC8 this is a fix! It's not perfect, but hell yes.

    I don't believe the vendor is yet an inmate, so contact him via Facebook. His name is Tonino Ambrosano and his company is Tusnami Racing Team. The kit cost me 150€ delivered to France... other locations may differ I guess.


    I hope this helps someone out there in ADV land.

    Cheers... Paul
    #1
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  2. Bonnie & Clyde

    Bonnie & Clyde Wishing I was riding RTW

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    Thanks Paul! I saw this kit on a Google search that sent me to Facebook. I don't have an account for Facebook but from what I could see it looked promising. Can you post the contact information I might order it and do it this winter
    #2
  3. Spyrious

    Spyrious Want to go offroad

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    Is that the kit from kapriony?
    #3
  4. GezwindeSpoed

    GezwindeSpoed Been here awhile

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    What also helps a lot is to change the cooling liquid from a standard 50% glycol to 20% glycol by mixing demi water and anti freeze yourself in the right ratio. By this you increase the specific heat of the liquid which means every liter can take up more heat without getting warmer so it has similar effect as pumping faster.
    #4
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  5. tinwelp

    tinwelp Professional Idiot

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    B&C,
    I've asked Tony for his contact details and will post here when I receive them. For the moment I don't know.
    I'll try to encourage him to join ADVrider too.
    Cheers... Paul
    #5
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  6. tinwelp

    tinwelp Professional Idiot

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    Spy,
    I don't think so, but I cannot be sure. In fact I've not seen their kit, so it's not out of the question.
    Cheers... Paul
    #6
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  7. tinwelp

    tinwelp Professional Idiot

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    Gez,
    yup, I agree. I failed to mention that I'd already tried running plain deionized water as a temporary fix too. There was a small improvement in overall running temperature, but it would still run away in the 'stoplight situation'. I'm currently running about 1/3 antifreeze to water. Probably enough to give protection down to -20°C, which is 5°C below the lowest I've ever seen in the area where I live.

    Cheers... Paul
    #7
  8. tinwelp

    tinwelp Professional Idiot

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    OK, here is Tony's contact page:
    upload_2019-9-16_9-32-26.png

    You can also use his email address which I'll send to you by PM to avoid flooding the guy with spam. Just send me a message.

    Cheers... Paul
    #8
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  9. opanos

    opanos Been here awhile

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    Hi Paul,

    I am not saying that this kit is not effective on cooling the engine more effectively, but it is kind of strange reading that you are facing overheating issues. Using a 950 adv model, which is probably more demanding in engine cooling, in relatively high temperatures, I had never had an overheated engine, and I only have the stock single fan. When talking about high temperatures I am talking about traffic jam and ambient temperature more than 40oC. Probably there is an other issue in your cooling system and by using a more efficient impeller, you are just masking what is causing overheating to your engine in the first place.
    #9
  10. tinwelp

    tinwelp Professional Idiot

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    Opanos,
    I hear you, but I don't think there's a problem. I've been through all the details looking for exactly that, including checking for head gasket leaks. All is as it should be. The only detrimental point of all my modifications is a slightly more tortuous path of the top radiator hose needed to avoid the tank. I could avoid that by modifying the hose connector at the top of the radiator, or simply fitting a 990 radiator, but I doubt the addition of a 90° elbow is going to restrict the flow substantially. Maybe I'm wrong?

    I think the biggest factor is my desire to run pretty lean around idle. I'm quite sure that if I were to return everything back to standard all would be fine. That's not going to happen though, so for me, this is a viable (and easy) solution.

    However, looking at the bigger picture, there are certainly other guys out there with cooling issues on the LC8, and this kit irrefutably improves cooling.

    Cheers... Paul
    #10
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  11. Tonino

    Tonino n00b

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    Many Thanks Paul ...
    #11
  12. rattis

    rattis Long timer

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    My 990 tends to overheat in stop and go and it has two fans and has been burped ad nauseam.
    I think the idea is good but the actual impeller looks a bit " crude" to put it mildly, somebody should get some programming skills and know how to use a 5 axis mill. There's a LOT of loss in that design.
    But then again if it works it's good an a more useable farkle than many others.
    #12
  13. tinwelp

    tinwelp Professional Idiot

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    rattis,
    yup, I've done a bit of pump design in my time and I agree it's not going to be very efficient, but it works. It could be a lot better. The point here is someone has actually done something about the problem. Is such criticism really warranted?

    Cheers... Paul
    #13
  14. gefr

    gefr Life is a trip

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    East Med, Greece
    This looks like a move to the right direction.
    I lately had a w/p failure and replaced it at a workshop. The mechanic told me the blades have worn in the pump cover. The safety ring had given in and the axle moved outwards, allowing the pump fins to touch the cover.
    The mechanic told me that happens often and is not because of faulty installation. If that is the case, I would feel worried the improved metal fins would eat the pump cover.
    Cheers
    #14
  15. zeegman

    zeegman Been here awhile

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    Hi Tinwelp,

    thanks for the info. Did your water pump blades hit the waterpump cover and axle moved in and out?
    I have the dreaded stoplight overheat situation too on 2013 Baja that was not overheating when I got it.
    It now regularly overheats in the last 5000km at stoplight sometimes pissing coolant.
    I replaced radiator cap, thermostat, fan thermoswitch, flushed coolant, added new coolant, burped multiple times - no improvement.
    Radiator and engine water channels seemed to be free flowing when coolant was flushed - can some water channels get blocked or plugged - hard to see inside engine channels?
    Will check water pump next but see no pleats in oil filter or milkshake on clutch cover and water pump blades were not hitting cover as far as I could tell.
    Bike run is running a little rich and not sure why this is happening.
    Might give this a try.

    Thanks,
    Mike Z
    #15
  16. GezwindeSpoed

    GezwindeSpoed Been here awhile

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    I once had a head gasket failure (whirl pool like coolant reservoir), symptoms were also overheating in stop and go and it was blowing out coolant.
    #16
  17. tinwelp

    tinwelp Professional Idiot

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    Hi Mike,
    no, my original pump was perfectly OK. It's even on the original factory seals despite having done over 80,000km now. There's no evidence to suggest the impeller has ever touched the cover.
    During my various attempts to fix my problem I've back-flushed everything several times, even removing the radiator looking for evidence of clogging, but I've never found anything to suggest a problem with this. In your case, maybe it's worth looking a little closer though. Pull the radiator off, stand it upside-down and back-flush with a hosepipe for a few minutes, checking all the air fins are open and straight whilst you wait.

    Cheers... Paul
    #17
  18. zeegman

    zeegman Been here awhile

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    Thanks for the info.
    Every bit of knowledge helps inch closer to a solution.
    MZ
    #18
  19. Whodatschrome

    Whodatschrome Long timer

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    my 2 cents?...the spacer needs to be anodized orange.
    #19
  20. rattis

    rattis Long timer

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    Bottom line
    #20