Testing oil pressure relief valve

[scrambler]

This weekend I`ve made a little experiment and I assembled the oil circulation system with the tank to test the modified oil passages, to flush the main oil gallery and to test the pressure relief valve in which I duplicated the shims to slightly increase the maximum oil pressure. Now the oil pressure is set to 70 psi instead of 60, this mod will increase the oil flow to the cylinder head. I made a video about it, see the link below. The drill that I used was spinning at around 350 rpm at highest, that is 700 at the crank. Note that the cylinder head supplying hose is closed. Thanks to Argo for the tip!

[jayteenz]

Very cool - well done.
Perhaps Yamaha might be interested in a factory mod now !

[scrambler]

Yeah, sure! I`m wondering this huge amount of oil that just gets wasted through he valve could be used to deliver more oil to the gears tending to develop pitting. I`m thinking of installing some deflector plate there. 

[argo1974]

Deflector plate directing waste oil to 4th and 5th gear teeth would be great idea, seen those plates on lots of bikes, e.g. Suzuki added a plate to the T500 during the production.

[scrambler]

Argo, I looked at it, but there is not much space left for a deflector plate like that. Also, the oil should be going from the valve toward the gears upwards, so I discarded the idea. I think such a high amount of oil is delivered onto the gears right below the valve that they can easily distribute amongst the others and all the gears are overly lubricated over 2500 rpm. 

[argo1974]

Pitting on the gears of the 4th gear is pretty common though. Oil relief valve is located close to the gears of the 3rd gear. According to the pictures, relief valve outlet is directed backwards on my engines, so away from the gear teeth. I will follow the idea of distributing waste oil from relief valve to the gear sets.

[scrambler]

Yeah, for sure it won`t hurt to add a washer or shim and fix the valve so it sprinkles oil sideways. I`m considering to make two grooves just below the holes and fit two circlips and a steel plate in between. The plate would be like a little tub with 5 holes on it for dripping oil on the gears... That would be cool

[scrambler]

Finally I reconsidered the necessity of the extra-lubrication of the gears and fabricated an oil distributor plate/tub over the weekend. It`s held in place in between two circlips attached to the grooves I cut on the valve and one side is bolted to the engine case to prevent turning. 

[scrambler]

Here is how it looks when assembled. Now, in theory, when the valve opens, it fills up the tub with oil, which then is delivered right onto the gears on the output shaft through the five holes drilled on the bottom. The gears then forward the oil to the gears on the input shaft.