Oil pump Modification

[bigskyforever]

 Any market for an oil pump modification as per Nick Clarke's design? 2 mm. increase in pump width.

Just finished machining one on the weekend. Not for the faint at heart.

[scrambler]

This is the the first time I`m hearing about this, enlighten me please!

[bigskyforever]

It calls for a 13mm. wide oil pump in lieu of the standard 11mm. pump. You require machining a scavenger pump to 13mm. The inside housing rotor 341-13336-01-00 must be machined 2 mm. along with the seal cavity.

[scrambler]

That`s a great idea. Two mm is the upper limit? Or can it be even wider? Would you share some pics?

[bigskyforever]

This picture is courtesy of Nick Clarke.    I hope this is ok with Nick.  The photo highlights the original 11mm. wide pump with a machined rotor housing with a 15mm pump which I was told was too wide for the scavenger pump to keep up. I machined a rotor housing 2mm. and machined a new pump to 13mm.

The additional oil volume with a shimmed relief valve should give me all the oil flow I require for all day 70-80 mph highway riding.

[yamaha341]

Hi, That looks a worthwhile mod to the oil pump how much do you sell these for,, Is Nick Clarke posting anymore on here I remember about some mods he did for racing. cant find any updates ? can you point me toward him or posts thanks 341

[oldspice]

At this time I am doing my own testing on a TX to make sure there is no issue with the scavenger pump. Rather then relying on a bench test I am running this bike in traffic and highway driving.
I believe the upper limit is probably an increase of 2.5mm in width which should improve volume near 20%. Not earth shattering but would help flow at higher rpms. The volume of oil available for this bike should be around 4 litres which would require a larger reservoir which would also assist in slightly cooler operating temperatures and longer oil change intervals.

I presently ride two TX 750 and have a third engine on the bench for the next project. Once I have enough kms on this bike and I can prove the benefits I may build a few more kits and put them out there for other members.

[scrambler]

I myself is rebuilding now a TX engine as well and thought a lot about this modification. Finally I left the pump gears unchanged. If you look at the video that I made earlier about the oil relief valve, even with the extra shim it opens quite early, and lets the oil flow down to the sump. Therefore, IMHO at high rpm it won`t make any difference even if you double the capacity of the pump, all the extra oil flow gets wasted. It might only have some significance at low rpm, before the relief valve opens.

[bigskyforvever]

All is well when oil is cold and engine cool. Once your oil warms up the capacity of the pump will be reduced and thus oil flow will be reduced. (pump efficiency is reduced by heat) The same reason oil coolers work to keep temperatures down and engines together. The volume of oil returning to sump at the relief valve will also be reduced as temperatures rise. How much?

Everyone agrees that these engines have an issue supplying enough oil to the camshaft with the stock pressure setting. Pushing the relief setting up will slightly reduce the flow rate the moment high operating temperatures are reached as the pump is working harder to push the oil past the relief valve. IMHO

If you want to push this engine for longer intervals at higher speed and rpm and keep it together it would benefit from more oil volume. IMHO. 

Your assumption may be correct, but I prefer to have additional pump capacity on my side at this point.

[scrambler]

I agree with you in that high temperature greatly alters pump efficiency, I will hook up a pressure gauge on the bike and once it runs I`ll see what the pressure looks like when the engine is hot and at what rpm the valve blows off. Perhaps when the engine is at operating temperature the valve opens even at lower rpm because of the aeration increases the pressure on the valve. This is just guessing of course. With normal shimming the valve opens at around 2500rpm, but I can imagine that the extra flow helps preventing bearing failure in the head when the engine runs at idle and gets really hot while standing at a traffic light. 

[shaggymech]

Any word on if this worked? I would be interested.

[bigskyforever]

The modification does insure additional oil is available to the engine. The 2mm is a maximum as any more oil flow will over supply the scavenger pump. This modification along with the shimming of the relief valve will provide all the oil flow and pressure required for agressive riding. That being said most bikes with a shimmed relief valve and cooler will normally not have any issues.

bigskyforever

[scrambler]

Hi Bigsky,

Is this still available? I just torn apart my engine because of an oil leak after 3000 miles and I`m not too happy about what I saw in it...  So I`m considering adding some more oil at idle using increased pump capacity. 


Thanks,
Greg 

[sammiuk]

Jul 29, 2017 5:14:29 GMT -5 yamaha341 said:

Hi, That looks a worthwhile mod to the oil pump how much do you sell these for,, Is Nick Clarke posting anymore on here I remember about some mods he did for racing. cant find any updates ? can you point me toward him or posts thanks 341

[sammiuk]

Hi how much for these parts please , is this for the feed or scavenger might be a dumb question
Re Sammi