Follower scar oil tests (2018)

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WZ507 said:
The single bit of information offered here relates to lifter/cam force from a stock Commando cam and valve train, and since that is the most commonly found valve train in a Commando (that seems to do a pretty good job of chewing up quite a variety of cam/lifter related parts), thought this was a reasonable starting point. The highest force encountered at the lifter/cam interface occurs early in the valve lift cycle as the contact transitions from the constant velocity ramp to the flank of the cam, where the spring force is relatively low (just off the seat) and the inertial force is at a maximum and adds to the spring force. The inertial force of course changes with engine speed (spring force is ideally independent of engine speed), becoming larger with increasing rpm. In this example the following forces would be present.

Engine speed – 7000 rpm
Spring force ~ 100 lb
Inertial force maximum ~ 200 lb
Rocker ratio – 1.13
Force at lifter/cam interface – 339 lb [(100+200)*1.13]

The above information suggests that the test forces presently used are not somewhere out in left field, but rather in the correct ballpark. Recent reports here have shown oils dying at very low forces and some surviving beyond 500 lb force, so we’re certainly seeing oil performance across a broad spectrum of force.

As noted at the outset, this is a single data point to provide a feel for the lay of the land and is the gentlest we’ll be treating a cam in our Commandos. With more aggressive cam grinds and more engine rpm things get progressively harsher on the cam/lifter interface. However, this does not mean that any cam with longer duration is harsher, in fact all other things being equal, adding only more duration moderates the valve action resulting in gentler valve motion and in turn lower forces at the lifter/cam interface.

One more thing I’d hope would happen here is that Snotzo might look in and either bless the above numbers (then we’d know they’re real) or blow them out of the water as fake news. I’m quite certain that blindfolded with half his brain tied behind his back he could quickly make a determination regarding the correctness or otherwise of the subject forces.
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I have more cam/follower force information to offer. Received a personal communication from Snotzo regarding the information posted here previously on the maximum force occurring at the cam/follower interface. He confirmed that the technical approach employed to arrive at the posted forces was sound and noted that although he is fascinated by the oil thread will not be posting anything on the forum at this point in time due to other obligations (edit). However, he did provide additional force information for a different Norton cam/valve train system and informed that it was fine to post it on the forum. To that end I assembled Snotzo’s plots into a single image and attached it below.

The system he analyzed consisted of a PW3 cam and conical single spring of ovate wire section. Simulations were performed at 10, 1000, 2000, 3000 and 4000 cam rpm. The plots show force (vertical axis in N) vs cam angle (horizontal axis in cam degrees) for a single cam cycle at the given speeds.

The results show clearly that at low cam speeds the cam/follower forces are primarily a function of valve spring force whereas with increasing speed they become dominated by inertial forces (acceleration * valve train mass). It is also noteworthy that at the lowest rotation speed the cam/follower contact force is slightly higher than at the intermediate speeds.

The small little tit of a peak at the extreme left and right of each plot is due to acceleration as the stationary valve train encounters the cam opening/closing ramp. The next set of peaks, that grow to the largest peaks in the plot as speed is increased, are due to acceleration occurring as follower contact transitions from the lobe's opening/closing ramp to the flank.

I don’t know if the axis labels will be legible in the attached image so for clarity constructed the summary table below.

Follower scar oil tests (2018)


Follower scar oil tests (2018)
 
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comnoz said:
I bought this thinking I would use it for the first miles with my new motor but, not a chance. Obviously made for a modern water cooled OHC engine. Looks like break-down oil for a Norton.
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Hi Jim,
Regarding break in oil, what have you used in the past with good results? Also, how many miles and what riding conditions do you recommend?

Ed
 
APRRSV said:
Hi Jim,
Regarding break in oil, what have you used in the past with good results? Also, how many miles and what riding conditions do you recommend?

Ed
Click to expand...

Years ago I always used Rotella T4 for the first 100 to 200 miles.

For the last 10 years or so I have just assembled them with Mobil 1 v-twin in the tank and some Total Seal Quick Seat on the cylinders and used them like normal.

Which is better -I don't know -I have not seen a difference.

I would probably avoid running in a new engine with some of the very low friction oils available, but due the the extra heat you get from a fresh motor I do want something that is going to handle the temp and load.

From what I have seen so far -none of the "break-in" oils are up to even short time use in a Norton. They are designed for OHC motors with low valve train loads and probably water cooling.
 
Well, I can say that after looking over Snotzo's numbers that I won't be running my bike up to 8000 RPM. Unless I am missing something almost none of the oils tested have provided protection in film strength needed for those calculations.

It occurs to me of course that the difference between these tests and actual use is that 100% of the oil in our bikes does not stay at the follower interface for an hour. Which should help us breath a little easier about those rising oil temps. I've seen it commented on in various threads that a Commando oil tank shouldn't be filled to capacity for best results. I don't remember any longer why that was proposed, but it seems to me that keeping the tank topped up is critical in helping control oil temp and a lot easier to do than installing an oil cooler.
 
what I have seen so far -none of the "break-in" oils are up to even short time use in a Norton. They are designed for OHC motors with low valve train loads and probably water cooling.
Click to expand...

Thanks Jim.

Is Driven BR 15W50 break in oil on your list? If not, can you test if I send you some?

Ed
 
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Well, there is definitely a safety margin there due to the fact that the point of pressure moves across the follower face in a real motor, so the heat buildup does not happen as bad as it does with my tester.

But the heat is still there and you still have to get rid of it somehow.

A full oil tank helps a little as long as you don't oil the rear tire.
A oil cooler helps a little.

A good grade of oil that does not generate a lot of heat and still holds it's viscosity when it gets hot is the best in my opinion.

Every 10 degree rise in the temp of the oil at the pressure point is about the same as reducing the oil viscosity grade by 10 points.

The higher the viscosity of the oil at the pressure point, the thicker will be the protective film.

When your talking about a cam and follower, the thicker the oil film -the less the wear.
[Of course other things go into the wear problem but the viscosity is a big one when your talking about cam/follower wear.]

The temperature difference is why the wear mark of the VR1 is deeper than the wear mark from using the Royal Purple in the above video.

I was trying to catch the Castrol before it scarred the follower so you could see how much deeper the wear mark was. I was caught off guard both times.

If I were to run those oils with the temperature control enabled for the same load and time, then the wear mark would be about the same for all three.
 
APRRSV said:
From what I have seen so far -none of the "break-in" oils are up to even short time use in a Norton. They are designed for OHC motors with low valve train loads and probably water cooling.
Click to expand...

Thanks Jim.

Is Driven BR 15W50 break in oil on your list? If not, can you test if I send you some?

Ed

I don't have any of that one. So yes, send it and I will test it.

So far I have tested Lucas, O'Riley's and Motul break-in. The Motul looked like the best of those three.
 
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Thanks for both the video and the follow up comments. I don't know why I assumed this test would be fairly quiet. The video dispelled this myth, so I hope you have somewhere that you can listen to something besides the scar tester. Or do you just crank up the stereo and drown it out?
 
rvich said:
Well, I can say that after looking over Snotzo's numbers that I won't be running my bike up to 8000 RPM.
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Another data point that might be of interest is substituting the 2S cam into the stock Commando valve train. The 2S lobe has significantly higher acceleration than the stock Commando lobe, and when run to 8000 rpm exhibits a maximum force is 558 lb (vs 339 for stock cam), which is essentially the same force Snotzo determined for the PW3 lobe (551 lb). Somewhat comforting to see similar results for these 2 more aggressive cams.
 
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Some interesting data on 2004 and newer Sportsters measured at the tank. All of these bikes are air cooled. Mid point of distribution is 180 degrees F. Probably a number of different oils represented. Oil threads are as heated on that forum as this one. Temperature is easily measure with an optional oil fill cap that has a thermometer. Harley recommends at least 180 at tank to burn off combustion byproducts.
http://xlforum.net/forums/poll.php?do=showresults&pollid=282
 
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He confirmed that the technical approach employed to arrive at the posted forces was sound and noted that although he is fascinated by the oil thread will not be posting anything here on the forum.
 
rvich said:
Thanks for both the video and the follow up comments. I don't know why I assumed this test would be fairly quiet. The video dispelled this myth, so I hope you have somewhere that you can listen to something besides the scar tester. Or do you just crank up the stereo and drown it out?
Click to expand...

It's really not as loud as the video sounds. The camera just likes to pick up that frequency. And a lot of the noise is the blower which only runs intermittently during most of the testing.

And you add two air compressors and an air conditioner and a little music.
I don't even notice it -until the scream when the film fails and you get metal to metal.
 
I would be interested in the results for the Driven BR oil as well as that is what I use for break in.
Regards Mike
 
APRRSV said:
Does Snotzo have a problem with this forum?
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None whatsoever, he was simply engaged in other endeavors and didn't have the time to post.

Edit - Apologies, didn't see that Comnoz responded prior to posting the comment above.
 
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:):):):):):)
New winner!!!
______________________________________________________________________
Klotz_American_V-Twin_25W60_Synthetic
Follower scar oil tests (2018)

500 lb load -no scar
3.22 heat from high pressure shear
5.543 heat from friction
Medium/high heat from friction
Medium/high friction

A lot of heat from friction but I suspect this oil could handle the heat it makes.

____________________________________________________________________
Klotz_American_V-Twin_25W60_Synthetic with FR3 additive
Follower scar oil tests (2018)

500 lb load- no scar
2.46 heat from high pressure shear
4.016 heat from friction
Medium heat from friction
Medium friction

I'm looking forward to trying some of the nano/graphene friction reducers for this oil.

____________________________________________________________________
Yamalube_20W50_conventional
Follower scar oil tests (2018)

154 lb load
2.71 heat from high pressure shear
5.4 heat from friction
Medium friction
Medium/high heat from friction.

Good oil for an OHC Yamaha.
 
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