ESE's works engine tuner

**wobbly** · 12th January 2024, 18:35

And as I heard it there were already several " engineers " at Aprilia who were intent on doing R&D on Jans engines after he retired , working real hard to make it slower - after all what the hell did he know.

**katinas** · 12th January 2024, 18:51

Originally Posted by p12palof

You can see the extrange dip in the curve around 8200 rpm. The same effect can be observed in the 2:00 minute in this bike from Kaplan America with similar tuning...

The dip in this graph similarly replicates the CR 250 graphs with reed intake into the cylinder type. It is partly related to the Honda type of Boyesen side intake ports.
1991 Honda factory team prepare CR RC 250 for domestic championship with more power extracted from std cylinder at higher revs, to compensate looses with hydrostatic transmission. They cut off wall between B and intake to open flow through side ports directly to B (add photo) transfers . This eliminate usual dip at 8000 rpm, but slightly lost at 6500 rpm even with HPP valve.
Add other photos of factoryHonda NS 500 and RS 500 difference of side intake ports . Last is Hans Hummel type for RS 500.
Hummel s 7 transfers type cylinders have a good mid range power without exhaust power valves and often used for sidecars on TZ crankcase.

**jamathi** · 12th January 2024, 19:10

Originally Posted by wobbly

And as I heard it there were already several " engineers " at Aprilia who were intent on doing R&D on Jans engines after he retired , working real hard to make it slower - after all what the hell did he know.

The crankcase volume was regarded as too big, I Don't know their results.
Also a honda type exhaust port was tried: 1.5HP less...
To make place for this exhaust port the transfers had to be narrowed which costs power.
When I arrived at DERBI the very best cylinder gave 47.5HP
But most were anoud 46-46.5
So much for Czech flow benches....
Bartol's trick was to pay some money to some dishonest mechanics who then brought him the latest Honda cylinders
And copy them immediadiately.

**philou** · 12th January 2024, 20:49

**Frits Overmars** · 13th January 2024, 12:21

Thanks Philou. I always enjoy watching videos with Gabriele Gnani.
I picked up some Italian along the way but if you are into motorcycle racing, you may get the picture even if the language is new to you.
(Wob, I think it would be a great way for you to brush up on the lingo).
By the way Philou, your link https://www.youtube.com/watch?v=XTCWU78CjBw shows part 2.
Part 1 is here: https://www.youtube.com/watch?v=3tJupBvcIQs
And further below there are a number of other Gnani links.

Two things struck me while whatching part 2.
The first thing was Gabriele talking about his unique ultrafast shifting gearbox, a 'cambio a crociera scorrevole'.
It's a great box but unique it is not; Jan Thiel built such a rod & pawl gearbox in 1964, Gnanis year of birth if I'm not mistaken.
The second thing I noticed, was Gabrieles cell phone. You gotta love this:

Click image for larger version.

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**jamathi** · 13th January 2024, 16:56

Originally Posted by wobbly

Al , I sent a DM so you can pay for lunch , just for starters you have a THREE cone header and why do you want a diffuser after the rear cone - absolutely wrong.

Gradella , there is alot I cannot say about the R2 on here , but alot of work inside the duct was tested at the factory that I did not do.
Yes , the duct exit area is a bit too big , and the ears transition in the spigot is not elegant CNC programming at all - it could be done way better.
Here is my hand prototype.

And regarding Mr Bartol - yes he did copy and take credit for others work , but he also had access to a Czech flow analyzer that as I said other top class tuners regarded
as a seriously good tool.
Jan didnt like it , others did , so maybe Harold understood enough from its results to achieve serious power.
But then again , he simply copied an A Kit Honda exhaust , and even Witteveens attempt that Jan was forced to engineer around , was a far better pipe.

The only serious power bartol gained was by copying Honda.

**Javier Ruda** · 13th January 2024, 20:38

Hello Frits, I also love Gabriele Gnani passion when explaining the technical matters, and how he got altruistic help from a lot of people in his beginning.

Maybe you could clarify something he mentioned to the visitors. Literally he said that V-force type reeds are shit (“il V-force non va un cazzo“).

I think karts usually fit normal reed blocks and dirt bikes V-force type. Is there maybe more power from normal blocks and better control or response from V-force?

Another interesting link about Gnani:
https://youtu.be/xJPYXG1oGl4

**Frits Overmars** · 14th January 2024, 03:44

Originally Posted by Javier Ruda

Hello Frits, I also love Gabriele Gnani passion when explaining the technical matters, and how he got altruistic help from a lot of people in his beginning.
Maybe you could clarify something he mentioned to the visitors. Literally he said that V-force type reeds are shit (“il V-force non va un cazzo“).
I think karts usually fit normal reed blocks and dirt bikes V-force type. Is there maybe more power from normal blocks and better control or response from V-force?

Another interesting link about Gnani:
https://youtu.be/xJPYXG1oGl4

Thank you for the link Javier (this video has English subtitles !)
I do not have sufficient experience with V-force reeds to answer your question but I'm sure Wobbly can.

**katinas** · 14th January 2024, 05:31

Originally Posted by Javier Ruda

Another interesting link about Gnani:
https://youtu.be/xJPYXG1oGl4

So nice to listen and read. "Taking less risk as you get older because you have less to lose" inspirational quote to race as long as possible.

**wobbly** · 14th January 2024, 12:41

I only have a few documented real world experiences with VeeForce.
Fitst was many years ago when we had what was called 125 National Karts.
These had to be production MX motors , no race KZ types allowed.
I chose a TM125MX and spent months on the dyno dialing in the porting and pipe design.
Last thing to do was the reeds - it already had some trick Carbon Tech items in there I had tested with various thickness and backups.
So I bunged in a VF2 , the original screw together type that was designed for a CR125 or RS125 as the bolt pattern was identical, the only difference was the petal thickness.
Short story was that using the VF2 with thicker CR125 petals on the bottom Vee and RS 125 thinner ones on the top Vee along with the older ( shorter ) dead straight NX4 rubber manifold
that setup made damn near +2 Hp everywhere and +4 Hp at 12800 and won 4 straight NZ1 plates until the class was abandoned to KZ only.
The later VF3 and VF4 were never that good , were close - but still way better than anything I could conjure up from the TM reed block, no matter what petals or 3D printed stuffers I used.

The other tested scenario was for LC350 engines used in Post Classic race bikes.
When I did those only the VF4 for a Banshee were available - and eventually I gave in and bought some El Cheapo Chinesium copies that cost something idiotic like $25NZD each , free freight.
The slant eye copies were only different in that the petals were utter crap , but fitted with real VF replacements they worked perfectly and were reliable over many seasons of subsequent racing.
Back to back against any LC or Banshee reed I could find including Mossbarger and Boyesen replacements ,the VF4 in a racebike with 34mm or 35mm carbs were absolutely light years faster.
As close as it gets to any free lunch I have ever had.

The other projects were in 440 Champ Snow engines and lately in 500 Class Snow Dragracing. The big VeeForce is pretty much ubiquitous and a winner big time , but I am currently doing a Rotax 670
Rotary Valve project that will end up at 508cc ( overbore limit ) and will steal Niels sliding Gibbs. The big issue is that all the Rotaxes use the same valve size and means even with lots of weld/machining and oversize
carbon blades the ports on a twin are nowhere near on bore center - this looses alot of potential power - so even there the reed version might still be better.

**Javier Ruda** · 14th January 2024, 20:17

Thank you Wobbly for the explanation! That is a lot of accumulated experience. Maybe Gnani’s engine has some design not favorable to V-force.

**F5 Dave** · 15th January 2024, 11:56

As I've learnt from the dyno, you only have to have 1 mismatch and what should work better strangely doesn't. Every new combination needs testing, often with jetting and timing tweaks to reflect it in its proper light.

Goods sims probably circumnavigate some of this but beyond me. I'd bet entry errors account for a fair bit of non expected rear wheel hp going missing.

**husaberg** · 15th January 2024, 17:20

I was most puzzled by what he meant by crucifix or cruciform gearbox is this a google mixup?
it was also odd he went reed valve when he was previously disc valve. on the 80s at least.

**Grumph** · 15th January 2024, 18:19

Originally Posted by husaberg

I was most puzzled by what he meant by crucifix or cruciform gearbox is this a google mixup?
it was also odd he went reed valve when he was previously disc valve. on the 80s at least.

Rod through gearbox mainshaft pushes a piece out to lock a gear to the shaft. If it's a cross or cruciform shaped piece that's where the name comes from.

If it's a simple bar or a triangle shape you can call it something else. Maker's call. Similar box on early Lotus F1 cars was known as the queerbox. As previously discussed here.

**husaberg** · 15th January 2024, 19:32

Originally Posted by Grumph

Rod through gearbox mainshaft pushes a piece out to lock a gear to the shaft. If it's a cross or cruciform shaped piece that's where the name comes from.

If it's a simple bar or a triangle shape you can call it something else. Maker's call. Similar box on early Lotus F1 cars was known as the queerbox. As previously discussed here.

Okay google might be needed
what it said on wiki was basically it inadvertantly led to the formation of Cosworth.

Unreliability
Initial servicing of the Queerbox was undertaken by Graham Hill, then a mechanic at Lotus. [iii] It was soon discovered that the final drive was reliably unreliable, with all examples having the hypoid crown wheel pinion of their final drives fail at around fifty miles, much less than a single race. When improved oils meant that they lasted barely long enough to compete, it was then found that the gearbox section was also unreliable, with a worn box becoming unable to select a gear and leaving drivers with "a box full of neutrals".[4]

The task of fixing the Queerbox's unreliability problems, fell to Keith Duckworth, a young Lotus engineer. He then fell out with Chapman, who would not support the cost of the fix that Duckworth felt was needed, leading to Duckworth leaving to set-up Cosworth with Mike Costin.

okay three vespas came up

they have an internal t selector

https://www.youtube.com/watch?v=m3xyb7vvxGo.

Okay after a search

Originally Posted by Frits Overmars

Close. Your description is spot-on; only that rod was in the output shaft. Lotus even tried this system in Formula 1.
There must be an English name for this type of gearbox but I don't know it. Do you?
Dutch: trekspiebak
German: Ziehkeilgetriebe
Italian: cambio a crociera scorrevole
Which also demonstrates which is the most economical language

. Admitted: Italian is the best-sounding of these three.
Below the 9-speed Jamathi box of 1964 and the Bultaco box of 1977 when it had been mandatorily reduced to six speeds.
Attachment 335704 Attachment 335703 Attachment 335702

Originally Posted by Frits Overmars

By the way, the hideously expensive seamless-shift gearboxes in the Honda MotoGP works bikes are based on the same principle.
The clutch and the primary gearbox shaft of the Honda gearbox are quite conventional; they could have come out of an old Maico, Zündapp or Simson engine:
Attachment 335712

All secrets are brought together in the secondary gearbox shaft:
Attachment 335711

This secondary shaft looks like a cylinder from a security lock, with pawls that are operated from the inside by a rod that slides through the hollow gearbox shaft:
Attachment 335709

The essence of the Honda box can be seen in the picture below. The pawls in the shaft connect and disconnect the gears to the shaft:
Attachment 335710
In this drawing a tumbler Rao connects the gear to the shaft when the gear is rotating clockwise. And a tumbler Rbo is connecting the gear to the shaft when the gear is rotating anticlockwise. So in this drawing the gear is locked to the shaft.
The tumblers are governed from within the shaft via an axially moving rod.

Now if we perform an upshift, the shaft will need to rotate faster than the gear. Let us assume that the shaft is rotating clockwise. So we need to retract tumbler Rbo. Now the gear can still drive the shaft, but the shaft cannot drive the gear any more.

Next we engage tumbler Rao of the next gear, so it can also drive the shaft. Then we retract tumbler Rao of our original gear, so it can now freewheel in both directions. And finally we engage tumbler Rbo of the next gear so that it is now locked to the shaft.
That's all, folks: transporting torque from the gears to the shaft without interruption, both while shifting up and down.

Honda has filed patent applications for their seamless gearbox in Japan and the United States (patent applications 2010-203478 and US20110023639, respectively).
You can download the US patent document here: http://www.freepatentsonline.com/y2011/0023639.html

Originally Posted by Grumph

Rod and pawl is probably close enough - but I preferred the name the Lotus box earned - the Queerbox.

I suspect that the materials and machining technology of the time limited the torque and HP cpacity of that layout.
I have no doubt Honda have made it work with large amounts of Money...

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