Hot Hot Heat - Or How to Cool Your RC390.

[Dygear]

So it finally happened to me, the OEM fan has failed on my bike and it sounded like a baby seal dying during the process. Now that my bike is over heating I need to replace the fan (that I could do under warrantee) with something. Everyone has said that the SPAL 5.2 Inch Puller Fan is the way to go. Seeing as I'd be working on the cooling system for my bike, I figured I would also look around for better engine coolant as well. Engine Ice has a good review on the Duke 390 forum so I figured I might as well try that.

How To:
How To Service Your Motorcycle Cooling System | MC GARAGE - Motorcyclist Magazine
Duke 390 Forum: Spal Fan Instal How To
Making SPAL and OEM connector compatible
I'll let you all know how this turns out ... *Fingers Crossed*

1 Bars: 41.0 C / 105.8 F
2 Bars: 46.0 C / 114.8 F
3 Bars: 51.0 C / 123.8 F
4 Bars: 56.0 C / 132.8 F
5 Bars: 61.0 C / 141.8 F
6 Bars: 71.0 C / 159.8 F
7 Bars: 81.0 C / 177.8 F
8 Bars: 91.0 C / 195.8 F
9 Bars: 96.0 C / 204.8 F (Fan Kicks In)
Source: Temp Gauge KTM RC/Duke 390/200

 

[unicorn_violence]

Hey Dygear, while your at it there are a couple additional options you could do. you could also get some Samco insulated hoses. they should improve the cooling system on the bike. i plan on getting some once the race season is over.


you should also get a better radiator cap



both of those are available from a vendor on here.
i haven't used engine ice before, but i have heard good things about it.
getting a PCV and mapping the engine to run a little richer should also help the bike run cooler and not overheat (which causes the dreaded gasket fail)

 

[stevieboy]

Please explain how insulated hoses help improve cooling.

 

[Diploman]

The SPAL fan and Engine Ice have become the standard cooling upgrade for the Duke community and for many RC's as well. The upgraded radiator cap can prevent pressure leakage by some OEM caps into the coolant reservoir, causing "puking". Not sure about the benefits of the Samco hoses, but certainly they are higher quality than OEM.

 

[unicorn_violence]

well if you have a thin insulated hose, the coolant/water can increase its temp while traveling through the hose, especially if that hose is already hot (right next to the engine, etc). having a thick silicone hose prevents this from happening, since its transfers heat better. it might not be a massive improvement, but it will make the cooling process more efficient. also they are far more durable then stock hoses. if your replacing the radiator already, why not replace the hoses while your already down there?
also they look fancy which makes the bike fancy, which makes the rider fancy
( i will say you might only notice a difference when racing, since that is when temps are a lot higher).

 

[jjtard]

well if you have a thin insulated hose, the coolant/water can increase its temp while traveling through the hose, especially if that hose is already hot (right next to the engine, etc). having a thick silicone hose prevents this from happening, since its transfers heat better. it might not be a massive improvement, but it will make the cooling process more efficient. also they are far more durable then stock hoses. if your replacing the radiator already, why not replace the hoses while your already down there?
also they look fancy which makes the bike fancy, which makes the rider fancy
( i will say you might only notice a difference when racing, since that is when temps are a lot higher).

+1...I installed the 1.6 cap and Samco hoses. I also removed the radiator shroud and rubber that covers the entire top of the engine. Now, while the fan does kick on in traffic, the bike cools much quicker once moving than before. Don't know if it was one or all the mods...I'm in TX too so it's frkn hot out there now!!!

 

[stevieboy]

well if you have a thin insulated hose, the coolant/water can increase its temp while traveling through the hose, especially if that hose is already hot (right next to the engine, etc). having a thick silicone hose prevents this from happening, since its transfers heat better. it might not be a massive improvement, but it will make the cooling process more efficient. also they are far more durable then stock hoses. if your replacing the radiator already, why not replace the hoses while your already down there?
also they look fancy which makes the bike fancy, which makes the rider fancy
( i will say you might only notice a difference when racing, since that is when temps are a lot higher).

Black Body radiational cooling? I wouldn't think a hot hose would absorb heat but would give off heat.

 

[unicorn_violence]

Black Body radiational cooling? I wouldn't think a hot hose would absorb heat but would give off heat.

"Is there any performance advantage of running Samco over my original OEM hoses?
An efficient cooling system is key to maintaining horse power - especially when a bike is being pushed hard. Overheating bikes loose power – fitting Samco hoses can reduce the operating temperature of the bike by up to 8 degerees - which can mean gain of a horse power or two! Samco hoses insulate far better than stock hose, ensuring heat is taken away from the engine, to the radiator, allowing the radiator to work on the maximum temperature differential, which makes it more efficient."

Are there any other advantages of running Samco besides the performance and looks?
"With our in-house development team working closely with top race teams,Samco hoses are often designed to replace multiple OEM hose assembles which contain restrictions to flow. Our unique “zero-block” tooling ensures all hoses are made free from flashing to maximize your coolant flow, lowering temperature and preventing power loss"

 

[stevieboy]

Imagine that. The manufacturer says their product is great. I suppose it cant hurt to keep the heat in the hose rather than let it radiate off even slightly?

 

[unicorn_violence]

Imagine that. The manufacturer says their product is great. I suppose it cant hurt to keep the heat in the hose rather than let it radiate off even slightly?

yerrrp i had a good feeling you would say that. given your argument wouldn't it be an issue if the coolant heading back into the engine from the radiator was pulling heat from the hot hose before it even got to the engine? i think that's the main point i'm trying to make here. consistent flow+ insulating of cold antifreeze/water before entering the engine, any help to keep the engine cooling more efficiently on this particular bike i would consider a plus. im surprised you dont agree given your well known stance on the rc390.

 

[stevieboy]

yerrrp i had a good feeling you would say that. given your argument wouldn't it be an issue if the coolant heading back into the engine from the radiator was pulling heat from the hot hose before it even got to the engine? i think that's the main point i'm trying to make here. consistent flow+ insulating of cold antifreeze/water before entering the engine, any help to keep the engine cooling more efficiently on this particular bike i would consider a plus. im surprised you dont agree given your well known stance on the rc390.

The science doesn't allow the hose to get hotter than the liquid flowing through it. My well known stance on the Rc is not that well known evidently. My big problem was with the dealer I bought the bike from. I have resolved that problem. The bike is in for its first service right now.

 

[Rcdan]

Another option that seems like it ought to help is removing the rubber cover that sits over the engine. Seems like it would do a lot to hold heat in. I know mine seems to shed more heat going down the road since I removed it. At least going by the amount of warm air I feel coming out of the fairing.

 

[simpletty]

im thinkimg of retrofitting a l bigger radiator.

 

[unicorn_violence]

The science doesn't allow the hose to get hotter than the liquid flowing through it. My well known stance on the Rc is not that well known evidently. My big problem was with the dealer I bought the bike from. I have resolved that problem. The bike is in for its first service right now.

well if thats the case im in the wrong. although your previous posts on other threads led me to believe otherwise.
back to the topic. i don't agree with that statement. if that was the case, i wouldn't have to worry about my water pipes freezing in the winter. the whole process of liquid cooled is water absorbing the heat around it, and that could certainly include heat from outside a poorly insulated hose. same reason why my water inside my camelback bag hose gets hot. its not because the water was hot to begin with. it got hot from sitting in a hose that became hot from the outside temp. insulating that same camelback tube helps it from both freezing and becoming hot. the same process would work with coolant.
plenty of people use silicon tubing for bling factor. but its also used in almost all motorsports for several reasons INCLUDING a more efficient cooling system. i highly doubt racing teams use silicone hosing just for bling factor. after all, that's what racing graphics on fairings are for
they also mention using a more direct route of the hoses to minimize travel of the coolant. not sure if that's the case with the rc390 hoses though

 

[stevieboy]

Works for me if the outside air temp is higher than the 180 degree water inside the hose. Maybe you should eliminate the radiator and just add some additional hose instead.

 

[Dygear]

For efficient radiation of heat, you need a larger surface area to disperse the heat over. I don't think the hose will be an addition that I'll be adding, but I'll consider the cap and it's a real concern should the bike over pressure it's cooling system at the weakest link the OEM cap.

 

[SHOW SCARECROW]

A part of the radiator hose was replaced with aluminum pipes for cooling performance improvement
Effect became 1 bar less

 

[TennisFreak]

Better hoses wont do squat IMO because the fluid in the hoses will always be hotter than the air temp outside of them.

Now the aluminum hoses might do some good since aluminum is an excellent conductor and like I just said the coolant fluid will always be hotter than the outside air temp.
My only concern with those is they are no longer flexible and could create issues down the road.

 

[unicorn_violence]

Maybe you should eliminate the radiator and just add some additional hose instead.

you are oh so clever sir. good job
i'm not talking about the ambient air but the engine operating at a higher temp right next to the hose, but whatever, we are all entitled to our own opinions and keyboard bashing

but I'll consider the cap and it's a real concern should the bike over pressure it's cooling system at the weakest link the OEM cap.

if you go that route the vendor that has it is MNNTHBX

 

[Andy]

I thought the point of Silicone hoses is that they stand up better to higher pressures. Particularly in tuned engines the temperatures increase as does the pressure so performance hoses are better than OE which may fail.

Also add they look a bit Gucci too!