I've finally found an oil cooler for my RTL, it needs modding for oil line fitment, but should fit inside the front frame rails next to the header pipe.

I would really appreciate advice on connection from the engine and back. I see most people have taken the output from the bottom case oil hose point to the bottom of the oil cooler and the hose from the top of the oil cooler to the head banjo point. My question is, will all the oil drain out the cooler and hoses to the sump everytime the engine is shut off and will this cause oil starvation on start for a short period :0( if so, for how long. One final Q, does the oil pump Ok for any size cooler or should it be relatively small. Is there such a thing as a one way valve for oil coolers?

Any advice would be much appreciated.

This cooler is about 150 x 30 x 40mm.

http://www.trialscentral.com/forums/topic/6582-tlr-oil-cooler-fitting-advice/

Thanks for the link b40rt, I was thinking of routing the oil pump feed to the top of the oil cooler and exit out the bottom to the head feed, just like the last post showed, so that oil would stay in the cooler and almost immediately feed oil to the head on start up.

But in the parts list of the manual there is a diagram that shows (if I read it right) that it feeds oil in two directions, one to the bottom of the cooler, the other to the head and the oil returns from the cooler to the blanked off oil hole in the front lower part of the crank cases. Not quite sure if it the blank on the front of the clutch cover, or the front crankcase with the bolt in it.

Trouble is, I don't think there are any original bikes out there (89) that ever had oil coolers, as it was (afaik) an accessory. All the oil coolers I've ever seen have been from another source. Has anyone got a genuine Honda RTL250 oil cooler fitted to an 89 bike?

An experts opinion would be much appreciated.

(Edit went through the manual again and after the transmission diagram and specification data, I found this info, DOH) so I think I now understand, but any real life experience would be great.

Edited March 3, 201511 yr by jj65

I hope these images help. This is the correct way to run the lines.

When I seen this I thought to myself, " do you really need it? do you think you are going to move that thing fast enough for the airflow across the cooler to make any difference?"

Added weight and complexity with the garb hanging would not be worth anything to me on a trials bike, but whot do I know, all the Hondas and yams I have had over the last several decades ran fine without it, including running the p*** out of things. Non trials specific.

Edited March 3, 201511 yr by copemech

IMG_0737.JPGI hope these images help. This is the correct way to run the lines.IMG_0739.JPGIMG_0740.JPGIMG_0759.JPG

This configuration does not provide much interest, for example, one factory were often mounted differently...

Kcnarf.

IMG_0737.JPGI hope these images help. This is the correct way to run the lines.IMG_0739.JPGIMG_0740.JPGIMG_0759.JPG

Thats great JKmr1. Can I ask, did you use the 8mm sealing plug on the crankcase as shown in the diagram above? I want to put the cooler inside the down tubes. I believe you did it that way, as that was the only oil cooler you could get, if I rember rightly.

When I seen this I thought to myself, " do you really need it? do you think you are going to move that thing fast enough for the airflow across the cooler to make any difference?"

Added weight and complexity with the garb hanging would not be worth anything to me on a trials bike, but whot do I know, all the Hondas and yams I have had over the last several decades ran fine without it, including running the p*** out of things. Non trials specific.

An oil cooler can allow the engine to run upto 30 degrees cooler, (I know I won't get the maximum benefit of an oil cooler on a trials bike due to lack of fast airflow, but it will be better than not having one) which is beneficial for the engines life, the clutch etc. Obviously it doesn't have to have one, but when these engines have many parts that are no longer available, it makes sense to prolong its working life.

Weight can be reclaimed by saving weight elsewhere, but these bikes weigh over 85 kg anyway and as I intend to ride my RTL regulary, piece of mind is worth the extra weight and cost.

Extra oil captacity also worth while.

Also the oil cooler JJ65 has, weighs virtually nothing and the added benefit of extra cooling and oil capacity is surely worth while. Sometime people do things that are not strictly necessary, but they do it because they want to, or because you can. Nowt wrong with that.

Franck, I believe when Jkmr1 was building his bike, he was finding it very difficult to source a suitable oil cooler, so I guess that was the only one he could find at the time and it was too big to fit in between the frame down tubes.

I like your setup and it looks like JJ65 has found a similar cooler to yours, although yours has only 4 cooling vanes channels (sorry don't know what these are called), where as JJ65's has 6. Did you cut yours down, from 6 to 4?

It's an interesting thread.

Edited March 3, 201511 yr by shedracer

Valter's and JKMR1's are the bikes that has inspired my RTL. I'd like to keep all 6 vanes if I can, I have an idea on how to mount it, but until I've tried it with the header pipe (waiting for it to arrive) I won't know if it fits or not.

I have been told that RTL's run very hot and also you have to be careful with oil pressure, so plumbing the oil cooler needs to be done right. It would be nice if those who ride RTL's could give their thoughts on what they have done etc, as I'd really appreciate it aswell as others, I'm sure.

Edited March 6, 201511 yr by jj65

These bikes do in my opinion run far to hot for comfort, an oil cooler is something i have looked into fitting onto mine so i find this thread of particular interest, my motor was fully rebuilt 12 months ago, i always run good quality oil in my bike and i change it after every trial but what comes out is always black and well beaten,

I have moved the footrests on my bike further back and lower, also head angle has been slightly altered, other than that its pretty standard.

This is my solution

Edited March 4, 201511 yr by fantic303

Nicely done fantic 303. love your work! No doubt you will also be criticised by some for the incorrect placement??

I have included another picture that clarifies oil flow through the cooler. Hope it helps.

Great picture Jkmr1, explains the oil hose connection perfectly. I see from the 89 manual, that it suggest a blanking plug should be used, Did you use one on yours?