ESE's works engine tuner

[seattle smitty]

but I hate the usual right angle belt drive setup that many use after seeing a video of one running
and during a dyno test the belt goes completely spastic at several rpm bands - so how often would that occur in a 30 lap final.
I am doing one at the moment with a simple straight belt on the side behind the ignition and a right angle cylkro gear drive behind the RV.

How much of the belt-drive shakes are due to the fact that the disk is way out of balance? Lots of racing outboards (Konigs) had rotary-valve drive-belts that made a right-angle turn, twice. They worked, for our short sprint-type racing, but never seemed like a very good solution for exactly the reason you describe. www.konny.cz (Konny bought the Konig tooling after Dieter Konig was killed in an ultralight flying accident).

Cylkro gears are new to me. As they seem to have a sliding action, rather than the mostly rolling interface of what used to be considered "proper" gears, do they always require lubrication, even for light loadings? To drive a rotary valve disk, would a dry, heat-cured moly coating keep them happy? For a single, could you make a disk with two windows and turn it at half-speed, eliminating the imbalance of the disk?

[Grumph]

As far as i can tell, Cylkro gears are simply the old contrate and pinion right angle set. As such,the problem in this application anyway is that you can't get a 1:1 ratio easily - or at all. So somewhere in the drive train to the disc there would have to be a step up. I'm assuming Wob's doing it with the belt stage.

As far as driving the disc half speed goes, Helmut Fath did that but also doubled up the discs with a contra rotating pair so as to get the required rapid opening.Complicated but apparently worth a couple of HP.

Given the loads involved driving the disc, I may have a look at plastic bevels....

[wobbly]

The Cylkro right angle drive gearset is designed such that it allows quite a big positional variation of the pinion shaft in one plane.
This is due to the face gear being like a rack, it matters little where on the rack the pinion sits, as long as there is tooth engagement.
As far as the ratio is concerned I have already ordered a 1:1 set off the shelf from the factory in Frits land, so thats no issue.
This means the axial sliding clearance on the RV blade can be accommodated without a splined drive, as the shaft with the pinion can simply float.
The gear drive will, I believe need lube,but as the side belt drive is the latest Gen 3 Syncroflex steel belted type it can be run in oil, but the small amount of liquid required will be flung all over
the place inside a cavity that drains vertically back down toward the gears and away from the belt.But sure once is all proven, maybe a molly coating would suffice with such light power loading of the teeth.
Think about what engines have the crank vertical.
The big issue with the usual twisted belt scenario is the tiny drive gears needed to fit behind the RV under the big inlet port.
They are under the recommended bend radius for even a small pitch HTD belt, so there are serious vibration harmonics running up and down the quite long runs
between pulleys - in my side drive the toothed pulleys are close to 50 PCD on 82 centres, so with an adjuster on the slack side there is very little unsupported belt run.
If the belt drive proves unreliable it can simply be replaced with 3 gears - but not my solution of choice .

[F5 Dave]

So this sounds cool. What is it going into Mista?

[wobbly]

Im just finishing off the manufacturing drawings now - i will ask if its appropriate to disclose anything and to what level on here.

[Grumph]

fair enough on the Cylkro gearset Wob - if you're happy great. I'd be interested to know the number of teeth on that set though as at a 1:1 ratio the pinion has to be quite big to avoid excessive angularity at the tooth face - which then brings a large contrate gear into the packaging picture...

Hmm, Vertical shaft eh, doubt if it's a lawnmower...Moving into Smitty's area of interest are we ?

[F5 Dave]

Gyro would make sense perhaps.

[Peter1962]

The Cylkro right angle drive gearset is designed such that it allows quite a big positional variation of the pinion shaft in one plane.
This is due to the face gear being like a rack, it matters little where on the rack the pinion sits, as long as there is tooth engagement.
As far as the ratio is concerned I have already ordered a 1:1 set off the shelf from the factory in Frits land, so thats no issue.
This means the axial sliding clearance on the RV blade can be accommodated without a splined drive, as the shaft with the pinion can simply float.
The gear drive will, I believe need lube,but as the side belt drive is the latest Gen 3 Syncroflex steel belted type it can be run in oil, but the small amount of liquid required will be flung all over
the place inside a cavity that drains vertically back down toward the gears and away from the belt.But sure once is all proven, maybe a molly coating would suffice with such light power loading of the teeth.
Think about what engines have the crank vertical.
The big issue with the usual twisted belt scenario is the tiny drive gears needed to fit behind the RV under the big inlet port.
They are under the recommended bend radius for even a small pitch HTD belt, so there are serious vibration harmonics running up and down the quite long runs
between pulleys - in my side drive the toothed pulleys are close to 50 PCD on 82 centres, so with an adjuster on the slack side there is very little unsupported belt run.
If the belt drive proves unreliable it can simply be replaced with 3 gears - but not my solution of choice .

So a cylkro gearset + Continental Conti Synchroflex AT Gen III timing belt, that should be bullet proof.
If that were te be mounted on a 50cc, like a derbi Euro 3 engine which has an oil pump, that pump could be used to lubricate the gearset and timing belt.

But I would love to see your construction on a modern enduro/Mx 300 cc engine like the TM 300 with its electronic powervalve. Then throw away the Keihin and replace with a lectron 38 equiped with a TPS and an ignitech programmable ignition.
In Germany, a ktm 380 already prooved that it can win in Supermoto against factory 450 4 strokes. I wonder what a modern 300 with rotary valve would do against those 4 strokes.

[Muciek]

Question about pipe flange.
I would like to reduce the pipe flange diameter entering cylinder because current is way too big compared to exh window. Could I use reduction like on drawing? Changing diameter of duct is impossible because of it shape ( impossible to screw in some stuffers or weld ). Would this make any sense to do it?
Drawing aspect is in cross section looking from cylinder top.

[Flettner]

Mallory metal, now I can start putting the crank together for the sleeve engine. It needs a lot of weight to balance the reciprocating parts. Still weighting for two more lumps.

[wobbly]

The Cylkro gearset in 1:1 ratio I am using is around 30mm diameter for both the face and pinion gear with 14 teeth - 1.5 Module.
The technology is well proven - Audi use them in the transfer gears of the 4 wheel drive cars.
Having the pinion able to move without introducing backlash, as a normal bevel setup would,made it a no brainer as it enabled
me to delete a splined shaft and hub for the rear RV to float on.
The Aprilia RSA was a nightmare to setup the bevel drive, needing dial gauges to set clearance etc,this thing is engaged perfectly at all times
as long as the shaft centres are CNC machined accurately into the case - fit and forget.

Re the Ex stub insert - any way you can do it will work well, as long as the area reduction can be blended smoothly the performance increase
is pretty dramatic.
Also gives you another variable to design the pipe around, as the increase in top end and overev can be taken for free, or this then enables the pipe
to be more optimised to better mid with no loss in top end power.

[peewee]

progress is alittle slow but still going. found a combination of parts that should work good together. suzuki, arctic cat, ktm and a couple bits from yamaha . cut this manually and its a pain in the ass. need to get a mini milling machine or something

[wobbly]

I have permission to post some pics of the rear RV engine, so here is a few to start.

[Grumph]

thanks Wob. Out of curiousity, how close was it to simply taking your right angle drive for the disc straight off the crank ? The disc center can't be far outside the main bearing on that side.

Edit - on closer inspection, no room.

[wobbly]

I tried many variations of concept before finally hitting on the belt/cylkro idea.
KISS being the buzzword, but severe lack of room due to use of a stock crank forced some compromises, when trying to minimise the
number of bearings/seals/shafts and the real issues of how the hell do you assemble the thing and then keep oil in the right places.