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The Dutch 450

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SteveD CB500K0:
I read every post (I’m sure others do too).

Even the really long ones.


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K2-K6:
I feel that in this particular area,  the original problem statement / issue,  of how to stop the camshaft and followers wearing is very very difficult to draw real conclusions that withstand detailed scrutiny. This is made more of a problem by the assumption that a particular oil brand/specification is responsible for the lack of wear.

As others point out,  there is no real quantifiable, totally within normal specification engine, run through the same routine, to compare.

I feel it's entirely correct to make such an effort in setting the valve system to optimum ex factory spec. It also seems to me that to run with slightly larger tappet clearances during its initial running, post build term, has potentially big longer term positives. I'd do the same.

If you were to plot the loss of valve clearance against mileage and then compare to the servicing interval / specification published by Honda, you could observe if any wear would be controlled by that schedule and so prevent the followers riding on the cam base circle. The first service must, by expecting the most movement during initial mileage,  must be looked at as one of the most critical.

I think the jetting setup is also a very valid point in contributing to the oil condition. In this country we seem to use a dyno only for engines that are modified in some way. A routine check to really see what a standard bike is set to, can only give a more informed view of something you may have invested alot of time and money in.
You can see a very interesting parallel regarding this area in cars. As they moved to improving their emissions and ultimately a far better control of fuel air mixture,  they've been able to extend the oil change intervals as combustion contaminants are hugely reduced.
CV carbs are much better than slide at giving asymmetric fuelling that facilitates this invoice engines,  but you'd certainly have to verify what they are delivering.

As Mydlyfcrysys says,  it looks that by being so scrupulous in building and adjusting the engine then it's likely it would have succeeded whichever decent oil had been used. Jensen has taken out all the main issues before considering the oil.

K2-K6:
He came across this one as it's not obvious initially that there was no operating oil pressure relief valve fitted within the system mods.

Oil pressure relief as I understand it is, in any engine, there to protect the oil pump drive in the event of too much hydraulic pressure not being able to escape the oil feed architecture.

If you are running for example at high rpm and the system overpressurises from too little leakdown, then if the oil pump is unable to force the oil through the system it can shear the drive method. There's too much mass in the crank going round to stop that rotating. The pump would be compromised as it's a much weaker component.

Changing the oil viscosity upwards would also have increased that risk,  especially when up to temp and running fast.

You can't tell from the data what causes a change in engine BHP output when comparing the different viscosity oils,  but only one,  general engine friction from having a thicker oil on components was considered. I'd look at it as far more likely the energy was more associated with driving the oil pump itself, it will just consume more energy to pump thicker oil.

So it was running,  thicker oil,  higher capacity pump and no relief valve! I think he felt lucky he hadn't seen a failure.

K2-K6:
Changing to larger capacity oil pump seems to have been decided it was a dead end route.

As some other poster's pointed out, it's realistic to consider the whole system if you look at modifying any part of it. The later posts indicate that with 10/40 oil and std pump it will succeed it activating the pressure relief valve at higher rpm and hot oil.
This shows that by increasing the pump delivery rate it can't change oil flow in that region,  just more of it will bleed out through the valve.

It looks from his observations the cold running pressure relief is in response to oil viscosity increasing at those lowered temps,  obviously in combination with system restrictions.
The hot release though,  shows that the maximum flow of the system peaks before maximum revs with the pump going on to deliver excess flow above that threshold. This is the true system maximum flow,  and what the other poster's are saying. Just putting higher capacity pump / delivery can't increase the oil throughput beyond a certain point.

For that CB500T oil pump,  if you wished to increase the flow to the camshaft and altered the route to that area by increasing dimensions,  then you'd get a corresponding decrease in oil pressure for the 450 pump. You could then increase the pump delivery rate,  as they did,  pressure would go back up and you'd still have a balanced system but with increased flow to cams.

K2-K6:
The commonly given reason for cam and follower wear being the time it takes for oil to reach it from a cold start is worth looking at.

Stated reduction in oil arrival time from 40/60 secs down to 20/40 secs suggested,  as he observes,  that the drain down of the system after last use is affecting this. If you create a partial void in the system,  then the increased delivery of the 500T pump will simply fill the void in shorter time. It seems reasonable that his view of the filter system bleeding back into the sump is possible.

It's like having a full hose pipe,  turn on the tap and what's in the pipe immediately comes out the other end. Conversely,  empty hose pipe,  turn tap on and count the secs while water travels through the system.

Although still with what appears to be a long supply time,  the subject engine surpasses 30,000 miles with virtually no observable component wear. This has always been an area of interaction in which ZDDP is most useful.
I doubt if the tested oil has any appreciable level of it though. It's very difficult to gain that sort of information.

Added further thoughts; it would be worth considering the effect of using 500T oil pump and pairing it with 0w/30 viscosity oil to get higher flow but limit the excess pressure concern by capping viscosity max.

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