Thermostats on bikes

[mikey c]

i have a cbr600f1 engine for a race car - i dont understand how the thermostat works, there doesn't seem to be a bypass for the coolant to go through, i.e all the coolant always passes through the rad - whats the pont in having a thermostat if this is the case??

ideally i'd like to have a 'stat with a rad bypass for quicker engine warm up - has anyone here ever added this?

i've found these, this is the kind of thing i mean:
https://www.rscycles.com/images/therm_guhl/install_info.gif
https://www.rscycles.com/images/therm_guhl/flowpatterns_small.gif

they are a bit pricy and in america, is there a cheaper option?

cheers

mike

[stinkwheel]

There is one on every liquid cooled Japanese bike I have seen. As I remember, it doesn't have that 'bypass' tube. It just restricts the flow of fluid going to the radiator and gradually opens as it warms up.

It never fully obstructs the flow because there is a 1/4" hole in the mounting plate but it significantly reduces the flow untill the engine is warm.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Mongrel]

What Stinkwheel said^^^^.

You could plumb in a bypass but most bikes don't need it and I've never seen a bike or car that doesn't use some form of 'stat.

Without it the engine would never warm up properly in winter.

[Kickstart]

Hi

As above, added to which the pump / impeller can cope with next to no water flow.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[stinkwheel]

I suppose the upshot is, it works fine on the bike so there is no good reason the same setup shouldn't work in a car.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Mongrel]

The saying 'if it ain't broke, don't fix it' seems to be relevant here !

[mikey c]

thanks for the responses guys, i understand how it works now but it doesn't sound ideal - restricting the flow will just make the pump work harder against a higher pressure in the engine.

i have just noticed in the haynes book of lies for the bike that the 1000 model seems to have some sort of a bypass pipe that still goes back to the radiator but much lower down - will that operate more like i want it to?

the reason i ask is cos in the car the whole cooling system has a larger capacity, and we will be sprinting it, it needs to be up to temp before the start of a race and i'm not keen on the idea of heating the whole lot up

i may get to a bike breakers and see what i can find off a bigger bike, anyone know any good ones in the sheffield area?

anyone used that cheshire motorcycle salvage place on the net - they seem to have loads of stuff

mike

[Teaman]

you in sheffield?
have to pay us a visit mate,

Mick Flynn on langsett road usually has some meaty engines in stock
(I live near there, also work 5 mins walk from there)
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There is no point in ranting about someone stupid because there is nothing u can do about it. There is no cure for stupid.
Someone stupid does not realise they r stupid.stupidity is indistinguishable from malice U just have to accept that some people are thick as p1gsh1t and work around them.

[stinkwheel]

Even with a bypass you are only going to heat up the water jacket.

You want the oil to be heated up and the only way to do that is to force it through the oilways by running the engine with a load on it (ie driving about). The water can be warm while the oil is still stone cold.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[mikey c]

yeah i was thinkin of putting an oil-water heat exchanger on the rad bypass pipe, that way the oil gets heated by the water while its warming up

i love how quick you get sensible replies on this forum - thanks everyone. yeah i'm in sheffield - live near broomhill (i'm a student), i'll pop down to mick flynns tomorrow, theres a couple of other bits i'm after too

cheers

mike

[stinkwheel]

I suppose one way of approaching the problem of a cold-start then running the engine hard shortly after would be to use a different type of oil. Maybe a zero grade or 5w-40, something like that? I am no expert though.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Kickstart]

Hi

Think the pumps are designed to cope quite happily with little or no water flow.

I would be tempted to remove the pump and run an electric water pump. Think some of these work with a temperature sensor so they only pump when required.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[MikeyC]

Oi, theres only room for 1 Mike C on here, I was here first!

[feef]

[mikey c]

i went to mick flynns today, hes never really heard of the bypass type ones on a bike either, so i'll probably leave it how honda intended. i have thought about an EWP but they arent cheap, especially when you add the fancy controller you mention

i'm definately gonna put a thermostat on the oil circuit though, we have a bigger oil cooler so it'll take even longer for the oil to get hot - do any bikes come with them on or am i gonna have to get a demon thieves one?


cheers
mike

[Kickstart]

Hi

Plenty of bikes use oil coolers. Some of the FZR Yamahas use an oil filter mount that plumbs into the radiator. Check a late model FZR600 (not about the FZR600R, the single headlight version from about 1991 to 1993 has it though). I have a feeling that one of these might be easily modified to bolt onto a CBR600 engine.

Suspect plenty of other bikes have a similar system.

All the best

Keith
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