[TINKEN]

I am working on a small oil cooler modification project over in the Rhino forums and since the Wolverine has a similar unit, I thought I would share the mod here as well. We have been pioneering heat exchanger design on off road desert race bikes for some time now. And one of the projects I worked on with BMW/Husqvarna was these exchangers for Dakar rally race bikes. Adapting these to Wolverines would be pretty simple actually and I think I already make the hose fittings to make the project easier.

Here is the current configuration of oil coolers on the Wolverine.

Here is the oil cooler configuration on Viking side by sides.

The oil cooler is a radiator coolant/oil heat exchanger and is far more efficient as well as safer from debris. Also, not having to pump the oil all the way to the front of your vehicle and back before it is delivered to your engine's oil galleries is a huge plus. I am not exactly sure of the positioning of the Wolverine's oil cooler, is it in front of the radiator?

The Yamaha Viking oil cooler is quite expensive, however, I have found an inexpensive replacement on eBay in the form of a Kawasaki Ninja cooler.

I have ordered my Kawasaki oil heat exchanger and will continue to follow up on the project as I progress.

Here is the mod posting/progression in the Rhino forums.
http://www.rhinoforums.net/how/74162-oil-cooler.html

 

[Deeyoh]

Yes, the Wolverines is right in front of the radiator. Makes cleaning the radiator a bit tough unless you use a Radiator Genie.

 

[TINKEN]

So this mod could help with cleaning as well. Most of the newer vehicles are beginning to have the fluid heat exchangers, no idea why Yamaha left it off the Wolverine.

 

[Deeyoh]

I think a remote oil cooler isn't that bad actually. Gives more volume to the system. Always thought more oil you have the better..like my tractor takes almost 2 gallons of oil.

 

[TINKEN]

The oem system increases the oil capacity by a couple hundred cc's. The heat exchanger also increases the capacity, by how much I can't be certain until it arrives in the mail. Still to be determined if the increase in efficiency out weights the slight drop in capacity.

 

[madviking]

Tinken, this is a great project... oil cooling has always been a top priority for me. IME, using the oil to air unit in addition to the full liquid oil to coolant piece you suggest gives the best results. Do you have info from your BMW project that shows otherwise?

 

[TINKEN]

The oil to water transfer of heat is far more efficient. Removing the oil cooler from the front allows more cool air to the radiator.
There is also a pressure drop running through a long oil line. This heat exchanger has no oil pressure drop.

 

[Wi_Rider]

Definitely like the concept

 

[Mainerunr]

The oil to water transfer of heat is far more efficient. Removing the oil cooler from the front allows more cool air to the radiator.
There is also a pressure drop running through a long oil line. This heat exchanger has no oil pressure drop.

So it uses coolant rather than air to reduce the temperature of the oil?

 

[TINKEN]

So it uses coolant rather than air to reduce the temperature of the oil?

Yes. It will also stabilize the oil temperature much quicker upon warm up.

 

[Mainerunr]

Yes. It will also stabilize the oil temperature much quicker upon warm up.

And this causes no issues with additional heat added to the coolant?

While I understand what you mean about oil-water being more efficient than oil-air, it really depends on the rest of the variables. More efficient given the same delta-T and heat exchanger yes but with much reduced delta-T for oil-water vs oil-air and different heat exchanger design, that efficiency is not a given.

I guess I'd need to see the before and after numbers. I understand that more manufacturer's seem to be going this route but that could easily be mostly a cost consideration.

 

[TINKEN]

The issue is cost, not performance. The original Yamaha Grizzly engines did not come with oil coolers installed at all. Yamaha added the oil cooler adapter in order to compensate for the heavy chassis and passenger load of their side by sides. Yamaha installed this exact same unit on the Viking's in order to compensate for the addition load of hauling 1-4 additional occupants (upwards of 6 total occupants) with the same 686cc engine. There is also the issue that not only does the existing oil cooler block much of the air to the radiator, but that the heated air from the oil cooler passes into the radiator.



This is an actual image from the Yamaha Viking.

 

[madviking]

One can take all the measurements, and run all the math, but with this case in the end, my bet is on the external oil to air heat exchanger coming out on top. The oil to coolant unit, while selling for more as an individual replacement part, is actually less expensive overall, as it is a copper brazed stainless piece. It also has the added benefit of warming the engine oil up to operating temperature quite quickly, which is good for wear, and emissions. Again, in my experience, running both will be best... Move the oil to air unit into it's own stream of cooling air, and give it a dedicated fan for slow speed work. Also note that restriction issues are handled with a bypass valve in the take off plate.

 

[TINKEN]

Decided I would ask some of my baja racer friends while questioning air vs coolant cooled oil. Their response was that the new coolant based oil coolers are superior that their tests showed at least 30% greater efficiency over the air cooled models. They said that even Fluidyne is now adding oil coolers directly to their racing radiators. Air to oil coolers were obsolete. We'll see, got a couple of other projects on the fire at the moment.

Water cooled oil cooler (heat exchanger)

 

[madviking]

Given that everything is appropriately sized and designed for an apples to apples comparison, yes. There's so just so much to it all, so much to add up with so many variables that are always changing.

FWIW, I like the redundancy of having both units. Should something happen with the coolant system, mud plugged radiator? Fan not woking? The cooling system may need the extra built in capacity to hopefully keep things at a manageable temperature. Having the oil system depending solely on engine coolant for heat transfer, it is now suddenly in a position where manageable is no longer a possibility... and things will likely compound from there.

I guess my point is, if you have a machine like the Wolverine with reasonably well designed oil to air exchanger, I would not remove it and replace it with the Viking piece. I would stack the Viking, or a similar exchanger, into the system and have the best of all of it. I've done several systems like this over the years with great results.

 

[madviking]

Oh, the exchangers in the Maruha link are likely Laminova units. They can be purchased in all different sizes... Mocal makes some that are not too bad in price.