ESE's works engine tuner

**Ocean1** · 24th March 2014, 21:44

Originally Posted by WilDun

It's probably an investment casting, but the cam tracks will possibly be finish machined, too fuzzy to see.
However, producing the wax pattern itself would be quite a challenge!
Then again, I could be wrong.

I think you're right, there looks to be no draught on the webs. Looks a bit delicate but obviously worked.

A decade ago I would have got the wax 3d printed, nowadays I guess you'd 3d print shells directly.

**Forgi** · 25th March 2014, 00:04

Hello Wob!

I'd have a question if you don't mind!

What do you think why haven't become common the use of kart carburetors (tillotson, ibea, JHC etc.) among the gear class karts or scooters?
Rarely I can see a few attempts (http://www.tuningmatters.com/article...-tuning-guide/).

In the '90's we tired to use it in ICC class, and it worked very well, although we had to make notable modifications to make the carburetor able to carry enough gasoline.
Although in case of certain scooters (24mm and 50-90 cc) it would be enough, but they are not used.

These kart carburetors are quick and easy to set, but still everyone uses the ordinary carburetors. What is your opinion or experince?

**Grumph** · 25th March 2014, 06:05

Originally Posted by husaberg

Best i can do.............
When you think about it normal shift drums are heavy.......
I seem to remember the 50 i posted having a different set up i had a gif on how it worked and i think (the Sachs) of the 70's had something different.
The brits used a camplate.......

Unless they've used something trick as material, I'd doubt if that's much lighter than the "normal" shift drum. Any gain would come from the lower rotational inertia as the main masses are closer to the centerline. IMO just another example of Honda doing something "just because we can"....

**husaberg** · 25th March 2014, 07:29

Originally Posted by Grumph

Unless they've used something trick as material, I'd doubt if that's much lighter than the "normal" shift drum. Any gain would come from the lower rotational inertia as the main masses are closer to the centerline. IMO just another example of Honda doing something "just because we can"....

IMO Honda shift drums are generally bloody heavy, The MB one esp hefty, the NSR one pictured is very abbreviated it also is hollow ie light. The rotational inerta might help it change gear faster but i think it was a overall lightness exercise,Yes Honda often does stuff as a form of corporate Masturbation.

**wobbly** · 25th March 2014, 13:54

The really good kart carbs with flat slides and 3 jets are very expensive, that is the main reason they are not used.
Only issue I have heard about ( not my experience though ) is that some have complained the pumper carbs must be backed off the throttle
too much to make the gearbox change gears.
I brought back from the World Kart Champs in Vegas a new Tillotson carb that was designed to be used as a replacement for the 34mm Dellorto used on Rotax Max.
It made better power everywhere, and was super easy to tune - but as I understand it Rotax said no to changing it - that carb was sold to me "cheap " by the chief engineer
from Tillotson in Ireland, it cost 500USD cash.
Thats going onto a lucky 100cc bucket engine soon.

**WilDun** · 25th March 2014, 15:48

Originally Posted by Grumph

Unless they've used something trick as material, I'd doubt if that's much lighter than the "normal" shift drum. ....

In calling it "cast" I'm sure most of us are meaning good quality cast steel here, (as opposed to cast iron) - right?

**Grumph** · 25th March 2014, 17:01

Originally Posted by WilDun

In calling it "cast" I'm sure most of us are meaning good quality cast steel here, (as opposed to cast iron) - right?

yes - and unlike husa apparently, I'm accustomed to seeing shift drums which are (a) hollow and (b) only solid where they have to be..
late jap road stuff is pretty good for minimum material use. Even the post classic stuff I see is at least as light as that Honda drum.

It would be possible to use something like hard anodised 7075 alloy on short use stuff. Ti doesn't like rubbing so rule that out. That leaves good old steel....

**husaberg** · 25th March 2014, 17:09

Originally Posted by Grumph

yes - and unlike husa apparently, I'm accustomed to seeing shift drums which are (a) hollow and (b) only solid where they have to be..
late jap road stuff is pretty good for minimum material use. Even the post classic stuff I see is at least as light as that Honda drum.

It would be possible to use something like hard anodised 7075 alloy on short use stuff. Ti doesn't like rubbing so rule that out. That leaves good old steel....

Aye that remark resembles me.
I remember the story of TR750 with the mag and ti bits gearbox bits.
I did find this though while having a fosik.
Inside an AMA Superbike Suzuki engine.

http://www.mototuneusa.com/the_factory_superbike.htm

Honda F1 Car Shift drum should be the last pic
Honda RA106 Formula 1 Gear Selector Barrel

**Forgi** · 26th March 2014, 04:40

Originally Posted by wobbly

The really good kart carbs with flat slides and 3 jets are very expensive, that is the main reason they are not used.
Only issue I have heard about ( not my experience though ) is that some have complained the pumper carbs must be backed off the throttle
too much to make the gearbox change gears.
I brought back from the World Kart Champs in Vegas a new Tillotson carb that was designed to be used as a replacement for the 34mm Dellorto used on Rotax Max.
It made better power everywhere, and was super easy to tune - but as I understand it Rotax said no to changing it - that carb was sold to me "cheap " by the chief engineer
from Tillotson in Ireland, it cost 500USD cash.
Thats going onto a lucky 100cc bucket engine soon.

Thanks Wob! Well, I hoped you would say that!

You're right, unfortunately they are expensive, but I'm lucky to say that I have 1 or 2 good ones from the '90's.
Once we have tested on simsons, but I think we're gonna do it again.

**TZ350** · 26th March 2014, 22:12

Originally Posted by dmcca

So ive got some questions about Engmod2T... When modelling a reed cage that has an internal divider or stuffer before the reed petals, do you subtract the area of the divider from the area of entrance to the reed cage when calculating the 'diameter of the rubber block' (entered in the Inlet Port window)?

From an old thread in another forum but good info on modeling reed inlets in EngMod2T, link posted here so we don't loose track of some valuable reply's and info posted by Wobbly.

**steamroller** · 27th March 2014, 21:12

Originally Posted by wobbly

The really good kart carbs with flat slides and 3 jets are very expensive, that is the main reason they are not used.
Only issue I have heard about ( not my experience though ) is that some have complained the pumper carbs must be backed off the throttle
too much to make the gearbox change gears.
I brought back from the World Kart Champs in Vegas a new Tillotson carb that was designed to be used as a replacement for the 34mm Dellorto used on Rotax Max.
It made better power everywhere, and was super easy to tune - but as I understand it Rotax said no to changing it - that carb was sold to me "cheap " by the chief engineer
from Tillotson in Ireland, it cost 500USD cash.
Thats going onto a lucky 100cc bucket engine soon.

tweak