Crofter985'S KLX650C supermoto build

[Sandblaster]

Most of what I see that is bad on them is the head lost oiling.
What I have heard is that guys that don't normally ride long distances decide to go out on a extended ride.
After a fill up or two the top end goes not because of a bad oil pump but because of a harmonic frequency that develops at a higher throttle setting for extended periods of time causing oil to bypass the rings. So, it runs out of oil and there goes the top end.
That is what I have heard, but I have no proof of that.
But about 50% of the ones I part out have suffered from no oil in the top end.
If you want to play around with a KLR650 oil pump let me know and I will send you one.
I'd like to see what you come up with.
I suspect that others would as well..

[Crofter985]

Sounds like it's not really the pump to fault on the KLR, could be worth a look all the same.
Is the cam oiling a problem with the KLX650 bikes you break?

[Sandblaster]

It's been about 25% come in with bad heads from lack of oil.
That's on the street and the dirt versions.
So there is a issue but the big question is where?

[Crofter985]

It might not even be the oil pressure or flow that causes it, it's always the exhaust cam that's the bad one isn't it? It is on my ones anyway. On that thread on advrider the blame was put on the auto cam chain tensioner. Winching the cam down on to the journal.possibly no amount of oil pressure and flow would sort that. I'm going to convert my tensioner to manual. It seems to be a common choice.

[Sandblaster]

Yes, the exhaust cam always goes first.
I always assumed it was because of the heat and it's position in the oiling system but that makes sense.
It certainly wouldn't hurt to go manual..

[Crofter985]

There was an Australian inmate on advrider who did some mods on a KLX exhaust cam bearing he enlarged the slot in the lower(head) journal and crosshatched the surface with fine emery to hold the oil on the surface. He ran a race then stripped it and the journal was as it was before, not one mark on it. He would have been running a manual cam chain tensioner though.
I'm thinking I'll have to move more oil around for cooling as well, there will have to be a cooler maitrix somewhere, I probably don't have to put any more oil to the engine or more pressure, it's just the turbo that's the needy item. Iv been advised to ceramic coat the piston too. It sounds like a good idea, for two reasons, not so easy to melt a piston and heat stays in combustion chamber more as the ceramic coating is a heat barrier and lower under piston temps so oil stays cooler but that's a bit of theory, Im going to try to get some proof of this as I go along.

[Sandblaster]

Ceramic coating works as a heat barrier.
Never used it on a piston but why not, it sure works well on headers

Perhaps you might was to cross dill, chamfer, and micro-polish your cam journals, something similar to what they do on crank shafts..





Now that you have a mill, I wonder if there is room enough to go to a 2 piece bearing set up..

[Crofter985]

I ordered a couple more books off the internet on turbocharging, one had a really helpful bit on heat management and where heat should be and where it should not, etc.... There is a HP potential with ceramic coating the piston and combustion chamber. The score is, when the fuel mixture ignites, if the surfaces of the piston and combustion chamber are cold the heat/power of the charge soaks into the metal. The more heat retained within the combustion chamber the more the gasses expands and produces power. The heat thing is a bitch though because heat melts metal eventually ( Pistons & exhaust valves ) and heat degrades lubricity of the oil. I read a thing, probably 25 years ago, about a engine built using many ceramic parts, that had no cooling system, efficiency lies in having the engine running hot it would seem.
Come to think of it, race radiator caps up pressure in the cooling and race thermostats increase temprature in the cooling system. All things that would help efficiency.

What is cross drilling? And what is the idea?

I have considdered the shell bearing idea, setting in a brass half bearing into the bottom journal??? There are many options.

[Sandblaster]

Cross drilling the cam journal is drilling a hole all the way through the bearing journal on the cam itself, then chamfering the ends such as shown in the pic below.



Obviously that is a crank in the pic, not a cam but the principal is the same.
That should help retain more oil where you need it.

[Crofter985]

Well it's been a while. With no progress. There's been a lot of other stuff on. But I've now got a bit of time, well I'm making time.
Right the oil pump, I got going with this yesterday morning. I have a couple of spare oil pumps now so I started cutting one up to make a 5mm spacer to be able to fit the 12mm thick gear from the scavenge pump. That bit was fairly straight forward. Then I made a 5mm longer shaft. Again really not a big job, so I now have the oil pump.


There it is, on the right is the standard pump and all the bits and then the pump with the 5mm larger gear on the left.