to thermostat or not to thermostat?

[zoltanp1967]

that is the question. sure it will take longer to warm up, but i should run less of a risk of overheating, right?

I'd love to hear from you if you are NOT running a thermostat in your bike please. Does it get up to temp in this cold winter?
z

[seven-eleven]

As u know it will take longer to warm up and may run cooler but engines are designed to run at a certain temperatures and the thermostat not only regulates the temperature of the engine via water flow and keeps it in its designed range but more importantly keeps all cylinders at an even temperatures for better performance ect..running a engine too cold can be just as bad as too hot as constant running temperature tolerences aren't met.
Simple solution for it and all water cooled engines is to change it every year or so,5 or 10 bucks is little price to pay for a cooked engine (who hasnt blown a head gasket likely due to a faulty/old thermo)or the one who tosses it over his shoulder causing it to run to cold likely causing unnecessary knocks and poorer economy and likely power.
Just my experience as a fitter/plant mechanic but we aren't holding it flat stick for 20 mintues racing them.

[sbutler]

I have to agree ..But I had it around the other way. But both are possable.
With no thermo the water can be pumped unrestrtcted & the result is the water is pumped to fast through the radiator & hasnt had time to be cooled corectly. Had that happen with a car I had. Just ran hot all the time. An old guy said has it got the right thermostat in it. I said I took it out. He said fit lower temp one & see what happens. Bugger me the car warmed up propley, & ran cooler. IMO run a lower temp thermstat. So thats my story. Hope you enjoyed it.

[seven-eleven]

[quote="sbutler"]With no thermo the water can be pumped unrestrtcted & the result is the water is pumped to fast through the radiator & hasnt had time to be cooled corectly.[quote]

Thats true and another downside for sure.

Only problem might be running a lower temp thermo is the cars engine mapping may think its still cold and run the choke but if its in the cpu's limits thats ok,otherwise re tune it to suit.My only main concern is if the running temp is too low it may create excessive wear with parts not being and getting upto full expantion temperature creating play in bearings.One example maybe valve clearences and how they close up when hot and upto running temp.

[sbutler]

With no thermo the water can be pumped unrestrtcted & the result is the water is pumped to fast through the radiator & hasnt had time to be cooled corectly.

Thats true and another downside for sure.

Only problem might be running a lower temp thermo is the cars engine mapping may think its still cold and run the choke but if its in the cpu's limits thats ok,otherwise re tune it to suit.My only main concern is if the running temp is too low it may create excessive wear with parts not being and getting upto full expantion temperature creating play in bearings.One example maybe valve clearences and how they close up when hot and upto running temp.

Yep thats how you extract a few extra HP The ECU thinks the engine is a little colder & in turn pumps a little more fuel in.
Works with current V8s anyways. But I think Zol is talking about the FZ750, but im not sure.

[Jeda]

Thermostats are there for good reason.....
first to quickly raise the engine to normal operating temperature
second to maintain the minimum temp under all conditions
third to control coolant flow , meaning that if the coolant flow is too
fast ,over heating may occur because the there is insufficient time in the radiator
before it is again heated by the engine , a case of this is some ford v8's (first hand experience)

if you suffering overheating your generating more heat that the cooling system can dissipate.
thats either too much horsepower ,coolant loss,head gasket leakage,low radiator pressure or faulty seal
(•Each 10 kPa (1.45 PSI) of cap-rated pressure changes the boiling point by 2°C (3.6°F). ,
too small a radiator,Blocked radiator or paritaly blocked therefore reduced cooling capacity ,insufficient coolant volume,incorect ignition timing
Advaced or retarded,too lean ,and yes thermostat if it's too high opening temp or stuck shut or even fitted incorrectly.

my 2 bob's worth is run the correct themostat the pros far out way any cons

[HaggLE]

Your temp guage tells you the water temp on the engine side of thermostat valve, let's say it opens at 82c, it's now flowing coolant from the radiator that probably in the vicinity of 40-50c efficiently cooling the engine.
If you remove the thermostat the coolant temp in the radiator will be very similar to the temp in the engine and reducing the cooling systems ability to stop an overheating situation.

[HaggLE]

Oh and as for drilling holes in it, only required to bleed air. Personally if it needs one it will have it already.
I've seen a 1/4" hole in a thermostat of a 6 cyl cause the engine to not reach operating temp of 91c.

[michaelc]

What about measuring the oil temperature and usingthat temp to control the water jacket?

[zoltanp1967]

thanks all, all good points. we ran it at wakefield without the thermostat, it got qarm just as quickly as with it in, and ran at exactlky the same temp too. the reason i suspected it to be aproblem was cause the needle sat at just under the red area, but there are no numbers assigning heat temp values, and i expected it should sit a bit lower. it never got overheated though, but it is winter. they do have a small radiator, and we need to address this before summer - maybe fitting a yzf or r1 will help.
yes we will get a replacement one, and i did try and source a lower temp opening one, but the wholesaler said fat chance, coudn't even help me with the std one!
so more research to source one will follow...
oil temp is good, used to run it on the cb1100r - in the dipstick - but it was a bit tricky to check while racing of course one could get a digidash display for it ala buckets, along with head temp sensors, knock sensors, throttle pos sensor, airflow sensor etc etc.. might as well get an r1 ...
z

[Jeda]

Zoltan
Can i suggest you fit even temporarily a known acurate graduated temp gauge (measured in degrees )
just to confirm it is getting hot . I've seen it too often , inacurate original gauges