Mike like your tunnel cooler idea wanna know if it’s been working well wanna ask him questions please get back
More tunnel cooler talk.
- Thread starter dooman92
- Start date
I still like it. Downsides are it's heavier than radiators and it will get hot putting around on hard snow but it cools down quickly when I stop and pile snow on it. I drilled and tapped the end to a larger size at a slight angle to facilitate hose routing.
For someone that's having a hell of a time getting temps to stay up, despite engine jackets and a thermostat, would a tunnel cooler do better at keeping temps up? My temps never hit 180 unless the bike is standing still for a prolonged period of time running, and even with the thermostat, the radiators always ice up and are completely blocked. No heated bars.
The temps I ride in are usually 0 to 20, there are no trails to get to the good stuff, you're just in it right away and it's always deep and fluffy except for wind blown stuff, but we just move on down the road before we ride something like that.
The temps I ride in are usually 0 to 20, there are no trails to get to the good stuff, you're just in it right away and it's always deep and fluffy except for wind blown stuff, but we just move on down the road before we ride something like that.
Yes but I think It would be worth trying a valve (or you could just plug it for a ride if you knew it was going to be deep) to block coolant flow through one radiator before going to the trouble of adding a tunnel cooler. That would eliminate the possibility of your bypass coolant looping through your radiators. What temp is your themostat?
So I keep hearing the theory about the coolant circulating through the radiators from convection even when the thermostat is closed but I'm not buying it. With modern technology we shouldn't have to add manual valves to control water flow . I've only seen problems if the thermostat is stuck open or the plumbing is wrong. I've never used aftermarket stuff because the factory 4 stroke ktm tstats have a bypass and work great. Have any of you verified if your thermobob is working or stuck open? Can you take it apart and inspect it? Do they have a huge bleed hole in side? Can you plug it? Cheap china auto zone thermostats in cars only last one winter before they stick open. Thermo Bob might be made in China?
It's a 180F thermobob. Bought it and the temp guage with the pst jacket I put on.
eric, you know your ****, and i seldom disagree with your input but, convection is not a theory it is proven science. before circulating pumps gravity (convection) was how warm water was moved from the heat source (boiler) to the radiators to give up heat and heat the room cool the water. no pump to move the warm water at the boiler just angled pipes and convection. warm water rose to the radiator gave up heat, cooled and fell back to the boiler via a return pipe. the less dense (hot water) will rise give up heat to the radiator and the cooler water, heavier more dense, will fall back to the boiler (or engine case). if the radiator on our bikes is cold we do not need a pump and the thermostat has little effect. convection will cool that engine without any coolant moving other than the coolant rising and falling in the bottom rad hoses. start a bike and let it idle. the rads will get warm long before the thermostat opens. the reason tunnel coolers work better is they mostly eliminate convection. in our setups with lower rad hoses off bottom of rad to case, cool rad equals cool engine. gotta keep rads warm for any temp control.
tunnel cooler works much better because it eliminates the rise and fall of coolant from your rad to your engine. if you cover your rads and keep the rads warm you will get some improvement. in the powder there is so much area working to remove heat that you can't produce enough heat to overcome that heat loss.
Right I agree the convection is a real thing but if the thermo Bob really is completely closed then there can't be any flow at all between the hot side of the motor and the top rad hoses . the only convection can happen by hot water going up the bottom rad hose and cold water coming back down the same hose. I'm sure it's happening but would be very very minimal. If there is any heat in the top hose then you must have a circulation leak that is bypassing the thermostat somehow. The bypass plumbing needs to stay on the motor side of the thermostat and the thermostat needs to be fully closed.
My point is that I think there has to be more to it than just convection. If the convection is a real problem with a truly closed thermostat and proper plumbing no one would have a warm engine this year because it's been crazy deep every ride. We would all have to wrap the front of our radiators. If it is a real problem then it should be effecting everyone and we should all get rid of the radiators completely and do full tunnel coolers.
My point is that I think there has to be more to it than just convection. If the convection is a real problem with a truly closed thermostat and proper plumbing no one would have a warm engine this year because it's been crazy deep every ride. We would all have to wrap the front of our radiators. If it is a real problem then it should be effecting everyone and we should all get rid of the radiators completely and do full tunnel coolers.
One more thought that probably is negligible but the thermo Bob has a aluminum housing so the bypass coolant will constantly heat up the housing to possibly allow some heat transfer to the cold side coolant to cause some convection flow to the top radiator hose but seems like if this was a serious problem everyone would build thermostats with plastic housings like the factory does.
One problem we identified with the Thermo-Bob brand vs the C3 thermostat is the bypass outlet is too big on the Thermo-bob and allows too much fluid to move. The problem is compounded if you are running heated bars off of the bypass loop. The bars act like a rad. We solved the problem by adding a valve in the bypass line and choking it down. Oddly the large bypass also causes problems when the bike is super hot. When the thermostat is wide open the bypass still flows a ton of fluid and that fluid bypasses the rads allowing the bike to overheat. Choking off the bypass forces the fluid through the rads which cools the bike down. One of my bikes is a C3 setup and the other has a Thermo-bob, the C3 is a superior setup. Even though I don't do it deadheading the water pump on a dirt bike is really no big deal.
M5
M5
