Track Bikes.. Thermostat or Not?

[Steve Bass]

As per the title really...

Any thoughts on whether a track bike is better off with or without a thermostat?

Edited by Steve Bass on Wednesday 2nd April 21:15

[Rubin215]

No thermostat.

You're thrashing the tits off it so you want the cooling system operating at its maximum for best effect, a thermostat just creates a restriction to coolant flow.

[OverSteery]

It may not be as simple as that.
For a cars the A series engine, removal of the thermostat would cause some cylinders to run hot, as the lack of a thermostat changed the water flow.

I have no idea if this is a common feature, but I wouldn't move from the designed coolant flow without confirmation.

Why are you doing this? most modern bikes don't overheat on track? It's also slow warm up.

[Krikkit]

Leave it in unless you're really marginal on cooling - faster warmup and as noted, more flow isn't always a good thing.

[srob]

Yeah I can't see any advantage to removing it, except saving a few grams and the potential of a bit of complication?

You want the engine to warm up quickly and it's not unheard of to have to stop on track or queue to get back in the paddock etc.

Even race bikes used to run tape over the radiator that would let the engine warm up quickly then the rider would pull it off once up to temp or leave it on if it's a cold day!

[KTMsm]

I could see an advantage to running a cooler thermostat but I'll be wary of no thermostat -particularly as most people don't warm them up for long before going on track

Unless you have an overheating problem but then I'd suggest the issue is elsewhere

[OutInTheShed]

Steve Bass said:

As per the title really...

Any thoughts on whether a track bike is better off with or without a thermostat?

Edited by Steve Bass on Wednesday 2nd April 21:15

Are we talking Ducati?

I would look for specific advice for the particular engine in question.
Don't some of them have a bigger oil cooler for racing, with an oil thermostat?

[richhead]

Removing a thermostat wont fix an overheating issue, it may cause other issues tho.

[Sidecar Man]

What bike is it??
We always use a thermostat but a lower rated one.
We use a Thundercat one as it's fully open at 68 degrees

[s p a c e m a n]

Don't know about bikes but the trick with cars was to cut the insides of the thermostat out rather than run without it because of the flow issues. This was mainly for old stuff that didn't like idling in summer traffic.

[STR160]

I always ran a thermostat when racing. No reason to run without one, unless in a super hot or humid location. Often times needed to block off some radiator fins to keep the engine temp in range.

[Steve Bass]

So the bike in question is the 998 I'm rebuilding.
After taking it apart, there's a mishmash of hoses and copper pipes lashed together as a cooling circuit. Not cool at all....
So looking at replacing the hoses with a Samco kit however they only do the kit with the thermostat on circuit. And removing it makes some not insignificant changes to the pipes.
So, I'm thinking of taking it back to the standard set up and put the thermostat back in circuit.
Firstly, it'll help her warm up as she's really slow to get any temperature into the motor,, secondly, if temps are an issue I can gut or drill the thermostat internals to improve flow but before that, I'm going to reinstall a radiator fan to help if temps do get a little elevated, especially once she's back in the pits after a run.....

[Krikkit]

Sounds very sensible to me - since it's not a super stripped down race bike wanting to save every gram, the fan being there sounds like a very good idea. And ultimately a thermostat will reduce engine wear during cold starts.