About time for the spintron

I dug out all the old stuff from spin testing several years ago. I still have to assemble the partial motor and get a better drive system set up.

[video]http://youtu.be/0KAYHh20vfI[/video]

Looking forward to that!

Ken

We are all in suspense Jim... Hope you post on this soon!

I did a far less scientific version some while back using strobe lights etc with Dave Degens when trying for ever lighter valve train components in Triumph and Nourish race bikes.

And although I am still a huge fan of reducing valve train weight and spring pressures, we did find that if you go too low on spring pressure, (and to small on stem diameter) things start to fret and flex lot more, this fretting caused excessive wear of the alloy valve spring retainers, causing yet lower spring pressure, and so on until failure!

My solution at the time was to use titanium instead of alloy and install with slightly more pressure than the minimum we had tried. It was all guesswork, and although it worked, I always thought it would have been nice to conclude the topic properly.

Like you're doing...!

Getting closer.

dumb bunny is curious to know what this spintron is worth in extra thriling performance power? Has a limit been reached with current valve trains for a shorty short stroke? Can ya get a view of the cam bowing?

hobot said:

dumb bunny is curious to know what this spintron is worth in extra thriling performance power? Has a limit been reached with current valve trains for a shorty short stroke? Can ya get a view of the cam bowing?

Click to expand...

These are questions I aim to find out.

It's a little tough to see the cam but I do have a prox sensor under the cam that will show deflection. Jim

Hi Jim,

While you are at it.................

Would be neat to get a baseline amp draw (at various rpm) on that motor with only the mandrel crank, then with the cam, then with the cam, lifters and balance of the valve train. This should all convert back to power minus some loss for the electric motor.

How you going to lube the cam and valve train while doing all this. Inquisitive minds want to know.

Dances with Shrapnel said:

Hi Jim,

While you are at it.................

Would be neat to get a baseline amp draw (at various rpm) on that motor with only the mandrel crank, then with the cam, then with the cam, lifters and balance of the valve train. This should all convert back to power minus some loss for the electric motor.

How you going to lube the cam and valve train while doing all this. Inquisitive minds want to know.

Click to expand...

The oil pump is installed and the "crank" is drilled with oil passages that line up with the cam lobes. Jim

Ok Comnoz You are improving the breed while feeding our heads on very interesting things. in my limited state of the subject I'd fear even if I could see an issue going on there might be little ya can do about it w/o dramatically leaving Norton design and risk losing its cuteness. We all await your eventual news of new level of power per displacement achievements.

Can’t wait to see the video of the valves twirl about like Whirling Dervishes

Would we not want to see our valves turning to spread the wear or is that a bad thing in Norton heads?
What we would not want to see is valves bouncing, springs binding and camshaft flapping with push rods bowing.

hobot said:

Would we not want to see our valves turning to spread the wear or is that a bad thing in Norton heads?
What we would not want to see is valves bouncing, springs binding and camshaft flapping with push rods bowing.

Click to expand...

Norton valves are not equipped with rotator caps so they can not rotate very much or they will destroy the cap or spring seat.
When speeds get high and the valve spring is starting to have trouble keeping up [not saying out of control] then there will be some valve rotation.

Ok don't want to see stems rotating in Commandos. i know about engines with various provisions to rotate valves, just didn't know if Nortons did or not as elastic engine power/rpms. Might be educational to spintron the engine isolastics working and with different BF's.

hobot said:

. Might be educational to spintron the engine isolastics working and with different BF's.

Click to expand...

I have done that before. You can watch a dot moving round in ovals counter to engine rotation. Jim

Ah so comnoz I've traced the ovals in front and top to even resolve the vertical and horizontal elements for a sphere at base with a planetary ring system like Saturn impressed onto it but couldn't tell the direction of rotation. Do keep in mind that the isolatic motion is on similar scale and material as tires which is where I focus on. If ya can set up outside I could let ya film the details of crashing Peel on purpose in various ways to access what allows doing it even harsher w/o crashing.

The spintron is set up and test run. I need to set up a remote for the speed control.
Then I have to see what I can capture with the camera and come up with a way to transfer it to a modern video format for upload. Jim

[video]http://youtu.be/GqrFszvdPd8[/video]

Hm don't sound like real runing Norton w/o the head ringing and headers clanging but makes me wonder if rigid vs rubber mounting would feed back-reasonate with small parts under investigation when ya up rpm into red zone. Won't get far w/o bet oil in it eh.

I have uploaded 13 minutes worth of high speed video. It is in 5 sections separated by a video calibration screen.

The engine is now running a standard Commando cam, lifters, pushrods and rockers.

The head is a big valve head from a Dunstall 810 I picked up many years ago. It has 3mm oversized intakes and 1.5mm over exhausts. The valve springs are what came on it. I suspect they are S&W's with stock retainers. They are installed with 95lbs on the seat. The guides are new.

The 1st section of video is at 5530 RPM and recorded at 4500 frames per second and shows the intake valve spring.
The 2nd section is the same spring at 7266 RPM @ 4500 FPS.
The 3rd section is of the valve heads at 7255 RPM @ 4500 FPS
The 4th section is the same RPM at 9000 FPS -you can catch a little valve bounce.
The 5th section is a closeup at 18,000 FPS. You can see the valve bounce better but unfortunately u-tube cuts out too many frames to be able to see it every time. Two small bounces is obvious on the camera's monitor.

EDIT, The missing frames are due to the transfer software, not u-tube. Better software is forthcoming.

I varied the playback speed a few times but the engine speed stayed consistent.

So far I would say the valve control is very good with this setup. Jim

[video]http://youtu.be/zB0yJka9q90[/video]

In the footage of the valves from above it is clear to see the stem appears to bend as it moves and not simply travel up and down. It seems visible but less pronounced when viewed from the combustion chamber.
Is this due to value guide clearance allowing the valve to rock or is it flexing due to the loading and geometry of the rocker arm?
If the rocker arm is the main cause then what could be done to improve things and so take stress off the valve?

Great footage i have never seen valve spring coils flexing before even at full lift which surprised me. I aalways thought that under full load the tension in the spring would not allow this to happen. Thanks for teaching me something new and something i will be sure to remember next time am giving my bike a good fistful of revs

toppy said:

In the footage of the valves from above it is clear to see the stem appears to bend as it moves and not simply travel up and down. It seems visible but less pronounced when viewed from the combustion chamber.
Is this due to value guide clearance allowing the valve to rock or is it flexing due to the loading and geometry of the rocker arm?
If the rocker arm is the main cause then what could be done to improve things and so take stress off the valve?

Great footage i have never seen valve spring coils flexing before even at full lift which surprised me. I aalways thought that under full load the tension in the spring would not allow this to happen. Thanks for teaching me something new and something i will be sure to remember next time am giving my bike a good fistful of revs

Click to expand...

When I looked with a strobe at the lightweight valves I put in Nourish engines (the smallest I tried were 4mm stems) the flex was amazing. And Nourish engines have a far kinder rocker to valve angle. I would therefore imagine this was stem flex.

'Elephants feet' tappet adjusters reduce the side load a lot. But I suspect they would require some thought and changes to valve stem length in order to make them fit.

These are they: http://www.ebay.co.uk/itm/Engine-Valve- ... 567224d4b4