ESE's works engine tuner

[ken seeber]

SEAL FRICTION TEST RESULTS ARE NOW IN !!!!!!!!!!

At atmospheric pressure, the twin seal set up required 138 gm on Ø40.6 = 0.0275 Nm. The power required to overcome this friction at 14k rpm = 0.0403 kW. Remember this is for 2 seals. Note slightly less friction than before, mainly I think due to the better finished shaft surface.
A couple of points:

1. This is a quasi-static result and maybe things might change with running at actual speed. This could be tested with running the shaft between two bearings and two seal packs on the shaft. One would be used to measure the torque and the other used to apply pressure to the test piece, a passage interconnecting the two cavities inside the seal packs. See sketch below.




2. As Frits correctly pointed out, there is a radial force imposed on the seals, equal to the measured force. However, I feel that this force is relatively small in relation to the seeming stiffness of the seal moulding. Notwithstanding, this could be overcome using the method shown in the sketch.

3. Larry W suggested the effects of lower than atmosphere and we could do this, but content with the results.

Now, I’m sure that most won’t believe the results, but we did it quite a few times. I expected differently as well. So, if you are still sceptical, feel free to drop in this Friday arvo and have a play yourself. We’ll provide the beer, single malt whatever, E85 or even Marsala ice cream.

Oh, the results you might ask. The friction at 8 psi was exactly the same as at atmospheric. No change. Bugger, we had a really neat labyrinth set up designed for KZs.

Back to the Slider engine.

[husaberg]

SEAL FRICTION TEST RESULTS ARE NOW IN !!!!!!!!!!

At atmospheric pressure, the twin seal set up required 138 gm on Ø40.6 = 0.0275 Nm. The power required to overcome this friction at 14k rpm = 0.0403 kW. Remember this is for 2 seals. Note slightly less friction than before, mainly I think due to the better finished shaft surface.
A couple of points:

1. This is a quasi-static result and maybe things might change with running at actual speed. This could be tested with running the shaft between two bearings and two seal packs on the shaft. One would be used to measure the torque and the other used to apply pressure to the test piece, a passage interconnecting the two cavities inside the seal packs. See sketch below.




2. As Frits correctly pointed out, there is a radial force imposed on the seals, equal to the measured force. However, I feel that this force is relatively small in relation to the seeming stiffness of the seal moulding. Notwithstanding, this could be overcome using the method shown in the sketch.

3. Larry W suggested the effects of lower than atmosphere and we could do this, but content with the results.

Now, I’m sure that most won’t believe the results, but we did it quite a few times. I expected differently as well. So, if you are still sceptical, feel free to drop in this Friday arvo and have a play yourself. We’ll provide the beer, single malt whatever, E85 or even Marsala ice cream.

Oh, the results you might ask. The friction at 8 psi was exactly the same as at atmospheric. No change. Bugger, we had a really neat labyrinth set up designed for KZs.

Back to the Slider engine.

Ken hook engine crankshaft crankcase assembly to lathe,run at speed measure current draw.
Repeat with telfon seals
Then totally remove seals and repeat test (i think you will be surprised)
The Old style spring gater seals used in pommy shitters were HP killers, modern ones i would expect would be far better.

[tjbw]

SEAL FRICTION TEST RESULTS ARE NOW IN !!!!!!!!!!

...

Oh, the results you might ask. The friction at 8 psi was exactly the same as at atmospheric. No change. Bugger, we had a really neat labyrinth set up designed for KZs.

Back to the Slider engine.

I won, I won, well I was closest, I claim the prize of 'nothing' from Australia

Ken, is there any leakage at 8 psi?

[wobbly]

So the friction created by the backup radial spring on the seal lip far outweighs that of the case pressure - man that
is so counter intuitive, just like most things in a 2T.

Re Harolds work on the Yamaha.
He was the team boss for them in 125 with Ui, and he had ( sorry, he told me he had ) done a huge amount of work on a Jante developing a cylinder
that bolted straight onto the TZ125 that already had over 50 Hp.
This made me super depressed at the time ,as the cylinder we had done for the BSL500, made 55Hp ( 166cc ) at 12,000 so I thought I was well off the pace bmep wise.
Yamaha wouldnt let him use it on the team bike ( that was very slow ) but looking at the nicely made cylinder it appeared just like a RS125, except it had
the oval to round transition header off the 250 factory bikes.
As it later transpired the thing had nowhere near 50 Hp when it was tested on the Derby dyno, so his boasting to me ( and Derby obviously ) was largely bullshit.
This became obvious to me when we sent a 3D printed plastic cylinder to him to test/modify on the Jante - and we never saw a result, let alone any more power.
Much of his cylinder " design " work then went to KTM 250, as did the so called A Kit Honda pipe design.
That engine was in my opinion very well conceived as a symetric parallel twin ,firing at 90* with a balance shaft, but as with Derby, the cylinder and pipe were the Achilles heel
in that Jan at the same time had made huge steps forward, initially with Harolds Derby reed, and then with the Aprilia.

[adegnes]

Thumbs up for performing the tests!
200% from me, go high or go home!

Crap, I knew I should have gone home...



Nothing in it for a crowd of seasoned bucketeers I guess, but you could watch it for a laugh!

[jonny quest]

So 2 standard crankshaft seals rob .054hp

[wobbly]

On your advice Adegnes, Im into a Friday night rum session.Only 1/2 way so far but feeling pretty good at this point.

[adegnes]

On your advice Adegnes, Im into a Friday night rum session.Only 1/2 way so far but feeling pretty good at this point.

[breezy]

so , between the small end of a 2t conrod and the big end , conrods have a familiar shape.. would anybody in the know tell me why its shaped like this? is there any reason why this is?

[wobbly]

The norm is a non symmetric H section and this deals with the max stress concentrations of compression/elongation on the outer edges.
The only variation I have seen was earlier Rotax rods that were elliptical in shape ( for aero efficiency i assume ) , and a few 100cc kart engines that were slightly H
in section with the center hollowed out.
I always assumed this was to help the disrupted flow from the side RV, the reason Jan looked into putting the RV on the back.

Edit - Makr has given the correct term of I beam - not my idiot idea of a non symmetric H, sorry.

[husaberg]

so , between the small end of a 2t conrod and the big end , conrods have a familiar shape.. would anybody in the know tell me why its shaped like this? is there any reason why this is?

For different shapes look at an ariel Arrow or a Alpha conrod as used in 1960 villiers conversions like the Greeves silverstone.

The reasons i believe for the shapes were increased primary compression, which was of course all the rage back then. as the two strokes had cavernous crankcases and half cycle cranks.
In Irvings tuning for speed, they cover modifying two stroke rods for improved steamlining
The streamlined arrow rods were made and used in the IOM bike Herman Meier construsted were actually cheaper to make so it went into mass production.

Sorry i can't find a decent picture of any.

[Hemi Makutu]

If of interest: http://60sclassicmotorbikes.blogspot...ip-part-2.html

[TZ350]

Arrow Crank and Rods

[Hemi Makutu]

http://www.kawtriple.com/mraxl/files/crankrebuild.pdf

Note the collar/spacer the seals bear upon, was this the type included - in your seal friction test - Ken?

[husaberg]

Arrow Crank and Rods

pic two is the origional style pic one is a nice pic, good find