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Engine temperature - watercooled single

Discussion in 'Technical and Troubleshooting Torque' started by Chairman, Jun 5, 2006.

  1. The SZR has all sorts of clever gadgets that my SR is lacking - electric start, for example, a fuel light, mirrors and a meter for measuring the spicyness of your Mexican food (but I haven't worked out where to insert the taco).

    I also has a guage that was supposed to be removed at predelivery - I know it isn't permanent because it's labelled "Temp".

    This gauge never registers above 45degC. Even after a serious caning on the backroads near Warnambool it sat on 45 - still in the "blue" zone.

    Reading the SZR forums tells me that this is a "feature" of the bike. It is over-radiated. To give you an example, I rode the bike for about 20km to warm up the oil for an oil change and dropped the contents of the tank (its a dry sump). The oil was cool enough that I could dip my fingers in and hold them there - hot bath temperature, but not uncomfortable. On the SR, that would give me serious burns.

    I'm a bit worried about this (under-temperature), so I've blanked off 2/3 of the radiator (yes, seriously) and the gauge now reads 80deg - midway between the 40-50 (cold) and the 110-120(hot). This morning, riding in from Bacchus Marsh it sat at 60-70, yesterday idling in traffic it crept up to 100 before dropping back to 80 once I got moving.

    This is a big single, watercooled, fairly loose tolerances (from what I've read).

    Do these seem like reasonable temperatures?
  2. Gob, usually. There is another option that sort of cuts out the middleman, but unless you're an experienced salsa dancer it's much harder to chew that way.
  3. Interesting, buy I can't say I share your concerns about over-cooling.

    Happens the same to me of course, it rarely registers on the gauge. If you're caning it, it's actually less likely to register, it'll only register if you spend a lot of time below 40km/h.

    Do you really think it being too cool will affect long term reliability? I know engines work best at peak temp, and you want to warm things up before a ride, but it seems like a fairly over-engineered, indestructible thing. I've never heard stories of engine problems on this model.

    Besides, I think I heard a story that the temp gauge is actually in an inefficent place, and doesn't measure the temperature accurately? Readings may not be entirely accurate.
    I know what you mean about being able to dip your finger in the oil after a ride though.

    I think you should simply stop worrying and learn to love the machine. If it ain't broke...

    I'm getting mine repaired this week BTW. Can't wait to get back on it. Riding much more carefully this time :oops:
  4. Umm, obviously the gauge is working if the temperature of the oil reflects the low temperature reading on the gauge.

    Personally I would keep it the way you have it now (raditor partly covered) so the oil is a thinner and doing its job better. Im pretty sure the oil has a recomended temperature range.

    But im a newb so take my opinion with a grain of salt
  5. Is there also the option of looking at an oil recommended for the lower temperature range?
  6. The CBR1000RR's (inline 4) operating temp was 80 degrees (perhaps getting down to 78 at a decent clip on a cold day) ......getting around the city it would quickly get to 110ish....108 was fan time and 114 is engine cut out.

    So I'd expect operating temp of the single to be 80/4, about 40ish......you can work out the rest of the thresholds yourself.

    Any they say I'm helpful....I think.
  7. After I finished being a smartarse this is pretty much what I was thinking.

    But then again if its a feature/issue common to the model and other owners aren't reporting consequences then don't fix what isn't broken.
  8. Perhaps a different thermostat is available? However, if your radiator shroud works, I'd just go with that. Anotehr option may be a restrictor disc in teh top or bottom radiator hose. They work by slowing flow through the coling system, and wil let the coolant absorb more heat before it moves out of the block/head. The advantage of teh discs is your coolant sits in teh radiator longer to, so it's hard to really overheat an engine with them.
    I had a Nissan Skyline once, I used to do lots of night freeway driving. In winter, I had to cover about half the radiator to get it warm.
    Overcooling may cause long term issues with sludge buildup in oil and slightly accelerated bore wear, but it's not quite as bad as too hot.

    Regards, Andrew.
  9. i'd be checking to see if in fact it has got a thermostate at all, no thermostate can make any engine run cold etc etc.

    But yeah the part covered radiator works for me, how many of the older
    "anteater' Kenworths do you see in winter with up too 3/4 of there radiators covered so they can get up to normal operating temp :)
  10. The trouble is, other owners do report issues - excessive oil consumption is the most common (which suggests bore wear or valve guides - but the dealer I bought from did a compression reading. Cold and with the automatic decompressor operating, it was within spec)

    I'm not so concernd about oil viscosity - this can be fine tuned by choosing a 20/50, 30/70 etc. I was thinking more about all the little fiddly bits in engines that are machined with tolerances that assume a "normal" operating temperature. It might be, of course, that the SZR designers have already taken this into account and designed the tolerances accordingly BUT the same motor is used in the XTX660 Tenere, which doesn't have the same issue with temperature and therefore runs hotter in normal use. If the motors are the same but the "ideal" temperatures are different, I'm curious about why.

    Valve guides and valve adjusters, piston rings and rocker shafts are designed to have clearances that reduce under heating . When they wear in excess of tolerance, you replace or remachine them. But, if the bike is running cold and these parts aren't expanding, they're may already be running out of spec (valve adjusters, for example, are always set with the motor dead cold to allow for the valve stem growing longer when heated).

    Maybe, as Kols suggests, I need to worry less and ride more.
  11. I was thinking something along those lines... Ever tried to warm up a rotary without a thermostat... Never happens!
  12. Hi Mark

    45 is LOOOWWW.
    The Peg runs on 65 normal, fan kicking in at 83.
    It's engine is based on the old air-cooled Rotax 600/ early 90's.
    Seems to be right, as there's no probs at all with engine-life, many have gone past 100.000km.
    Recom oil is a 20/50, been using 15/60 semi-synth (car oil, Penrite HPR15) for years without probs.
  13. Any chance you can source some XTX660 Tenere parts to see if you get a better operating temp?
  14. big grain of salt here - for reference the two numbers on a multigrade oil are viscosity ratings when cold (the left one) and hot (the right one)

    ie 20W50 = 20 when cold, 50 when hot.

    They are made this way to be thin when cold to encourage good flow and work their way up to 'good and thick' when they get hot. Under pressure (eg between the journal bearing and shaft or between the faces of gears) the viscosity of oil goes up to somewhere around 'asphalt'