RX3 Cooling System

[detours]

I'm very interested in this mod but have almost nothing to add to this thread except a link to the Thermo-bob page:

http://shop.watt-man.com/Thermo-Bobs_c4.htm

FAQ - http://www.watt-man.com/Information__Articles.html

[dpl096]

Good thread and very interesting mod. If the ECU is receiving more accurate information might that better affect the mixtures and partially clear up the OCS issue? ? ?

[SpudRider]

After doing a bit of research, I see the stock thermostat in the KLR650 is removed during the installation of the Thermo-Bob. The Thermo-Bob bypass includes an automotive thermostat set for a higher temperature. The Thermo-Bob allows coolant to circulate bypassing the radiators before its thermostat opens. The early flow of coolant in the Thermo-Bob bypass is designed to allow the engine to reach ideal operating temperature more quickly, and to prevent the coolant from forming hot spots in the cylinder.

[detours]

They make a 3rd gen Thermo-bob for the Ninja 250 that might work for the RX3. It looks like it connects inline instead of bolting on, but I could be misunderstanding the diagrams.

http://shop.watt-man.com/Thermo-Bob-...-YEARS-TBN.htm

Spud, I think that's how it works. When the engine is cold, the bypass allows warm coolant to warm the engine faster. The second thermostat in the Thermo-bob closes the bypass at 195 degrees, so the radiators can do their job. This keeps the engine at a steady 185-195 degrees F, so water and fuel can vaporize and exit the crankcase.

[katflap]

Thanks detours, excellent info

I will definitely be taking a closer look at the thermobob. I wonder if the hose size connections are the same as the RX3.

I think we would have to remove the thermostat from our RX3 thermostat housing and then connect it somewhere between the cylinder head and the thermobob. By doing this our temp sensors will then be before the thermostat, where they need to be

[katflap]

I have been having a look at a home made bypass solution based on peters excellent idea.

By removing one of our temp sensors from the thermostat housing it maybe possible to screw in a bypass connection in its place.
Then refit the temp sensor in the boss of a connector.

One problem is that the parts to make this might not be a lot cheaper than just buying the thermobob.

[SpudRider]

Originally Posted by katflap

I have been having a look at a home made bypass solution based on peters excellent idea.

By removing one of our temp sensors from the thermostat housing it maybe possible to screw in a bypass connection in its place.
Then refit the temp sensor in the boss of a connector.

One problem is that the parts to make this might not be a lot cheaper than just buying the thermobob.

Attachment 5998

This is ingenious, but I like your first idea better.

Even if we relocate the stock thermostat housing, and install a Thermo-Bob downstream from it, I think we would still need to fit some type of adapter to accommodate the short hose with the tight bend which connects the right radiator to the water pump housing.

[katflap]

Originally Posted by SpudRider

This is ingenious, but I like your first idea better.

Even if we relocate the stock thermostat housing, and install a Thermo-Bob downstream from it, I think we would still need to fit some type of adapter to accommodate the short hose with the tight bend which connects the right radiator to the water pump housing.

I think your right spud,

Its going to take a bit of faffing, possibly with adapters, to get all to fit nicely

[SpudRider]

Originally Posted by katflap

Thanks detours, excellent info

I will definitely be taking a closer look at the thermobob. I wonder if the hose size connections are the same as the RX3.

I think we would have to remove the thermostat from our RX3 thermostat housing and then connect it somewhere between the cylinder head and the thermobob. By doing this our temp sensors will then be before the thermostat, where they need to be

You're right, Kat.

We could remove the stock thermostat, and relocate the stock thermostat housing closer to the outlet from the cylinder head. Then we could place the Thermo-Bob downstream from the stock thermostat housing, somewhere near the original location of the stock thermostat housing.

Of course, we do need to contact Watt-man, and see if any of his different Thermo-Bob kits will fit the hoses of the RX3.

[SpudRider]

As usual, thanks for posting the great information, amigo.

I found the following webpage which describes the operation and design of the Thermo-Bob. This webpage duplicates your information, but adds the missing piece of information I was seeking.

http://www.watt-man.com/uploads/TB_Testing.pdf

The bypass line does not contain a thermostat. The original thermostat is removed, and an automotive thermostat, with a higher opening temperature, is contained within the Thermo-Bob. The bypass line is located upstream of the thermostat in the Thermo-Bob. This bypass line is always open, since it does not contain a thermostat. However, the bypass line is much smaller in diameter than the main radiator line. Therefore, the bypass line is more restrictive, and is mostly bypassed after the thermostat in the Thermo-Bob itself opens.

[SpudRider]

The hose fitting on the top of the right radiator has an outside diameter of 3/4-inch. Therefore, the inside diameter of the hoses appears to 3/4-inch.

[katflap]

Originally Posted by SpudRider

The hose fitting on the top of the right radiator has an outside diameter of 3/4-inch. Therefore, the inside diameter of the hoses appears to 3/4-inch.

Brilliant spud, thanks

we have a fit

[kohburn]

Originally Posted by SpudRider

The hose fitting on the top of the right radiator has an outside diameter of 3/4-inch. Therefore, the inside diameter of the hoses appears to 3/4-inch.

is that 3/4 at the narrow part or 3/4 at the flare?

[SpudRider]

Originally Posted by kohburn

is that 3/4 at the narrow part or 3/4 at the flare?

The measurement was 3/4-inch at the narrow part of the pipe.

[kohburn]

this must be a carry over conversation from advrider. hope the bringing up the thermobob ends up being of some benefit to you guys.