ESE's works engine tuner

[TZ350]

Thanks F5, Skunk and I are working on getting our heads around corners.

I am like, Holy Shit another corner!!! Fawwwk where is the brakes?????? to fast to fast, can't look.

I will visualise the rabbit.

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[speedpro]

I got some good advice years ago - "slow down". I ended up 2 sec a lap faster at Puke. I still find it useful at new tracks or even at the start of practice to just go slow, get comfy, have a look around, and definitely don't try anything fast for quite a while. Some cruel people have suggested that is the way i ride all the time.

[TZ350]

I got some good advice years ago - "slow down". I ended up 2 sec a lap faster at Puke. I still find it useful at new tracks or even at the start of practice to just go slow, get comfy, have a look around, and definitely don't try anything fast for quite a while. Some cruel people have suggested that is the way i ride all the time.

Thanks Speedpro, good advice, I did give myself a bit of a head talk, slowed down and relaxed into trying the new riding style. Lots of people passed me easily but when on occasions I was able to keep my corner speed up instead of clutching it, the bike fair flew out of the corners on the throttle. I figured there are a lot of people in trouble (myself included) if I ever get the hang of this.

I know you can hire a key for the track. I would like to get down there during the week and just pootle around getting comfortable with the new riding style.

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[TZ350]

Aerodynamics.

I am looking at ducting air to the cylinder and head and generaly improving the aerodynamics.

Screen Scrape from Team Mad Dog Racing:-

If you decide to build a fairing from scratch, Cooper gave me the following hints: try to approximate a teardrop shape with a length to width ratio of 3 to 1. Have the widest point a third of the way back. Have a taper from front to back of 10 deg. preferred, and no more than 15 deg., as premature flow separation will occur and up the Cd. significantly. Keep the rider's body fully enclosed, with his back at the same 10 deg. angle. Pay special attention to the rear of the fairing, especially behind the rider as it is the rear of the bike where the greatest aerodynamic gains are to be made -- not at the front! When asked about the idea of the rear-mounted radiator, as used on the Britten and now on the James Parker-designed TZ-250 (Parker of RADD suspension fame), Cooper commented that it seemed logical, as the car guys have been doing it for years. He noted, however, that the ducting design is critical, and if done wrong can result in greater losses than a conventional design with regards to drag and cooling efficiency.

Regarding flow separation, it can be easily identified by taping tufts of yarn several inches long over the surface of the rider and body work. With a video camera and a chase car or bike, you can film the position of the tufts and identify where flow separation occurs. If the tufts are oscillating wildly, they are in turbulent air. If they are pulled back straight and tight against the body work, they are in laminat flow. This approach has been used by the aircraft and motor vehicle industries for years.

More of it can be read here:- http://race.commline.com/articles/TeamMadDog.html

I am going to try some of those aero ideas about ducting cooling air to the motor and will use the tufts of wool idea and a video camera to see how the air flow is moving.

Interesting about the riders back needing to be at 10 degrees.

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[Skunk]

I got some good advice years ago - "slow down". I ended up 2 sec a lap faster at Puke. I still find it useful at new tracks or even at the start of practice to just go slow, get comfy, have a look around, and definitely don't try anything fast for quite a while. Some cruel people have suggested that is the way i ride all the time.

Pickle told me the same thing. Did you two hear it at the same time or did you tell him? Can't imagine him telling you to slow down!

[Buckets4Me]

You are a greyhound following a mechanised rabbit that streaks around the corner, visualise that & let your eyes follow it.

Sits in dark room . . You are Lightening, You are Speed (Cars movie)

I am the minivan with the bed on the roof

[TZ350]

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Gordon Jennings on top end rebuilds, porting and piston clearance

“With pistons fitted to close .00016 to .00018 inch clearance will run faster and more reliably than one that’s a little loose. You are entitled to wonder why a tightly fitted piston should give a horsepower edge and have a lessened tendency to seize?”

http://www.bridgestonemotorcycle.com...d_rebuild6.pdf

and how you can sharpen your bike’s performance with a $20 investment in rifflers and rasps.

“Until you’ve tried it, do-it-yourself porting looks like the kind of work that should be easy, inexpensive, and a sure-fire way to coax more horsepower out of the motorcycles engine.” But…….

Down load the complete article here.

http://www.bridgestonemotorcycle.com...d_rebuild6.pdf

The complete 2stroketunershandbook can be down-loaded here:-

http://www.bridgestonemotorcycle.com...rshandbook.pdf

Gordon Jennings 2-stroke time area’s for porting can be found here:-

http://www.bridgestonemotorcycle.com...in_takers6.pdf

Do you really want to know about expansion chambers? Gordon Jennings

http://www.bridgestonemotorcycle.com...ou_really6.pdf

A lot of other good stuff can be found here:-

http://www.bridgestonemotorcycle.com/documents/

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[TZ350]

Port map calculator. I have an earlier version, it works great, costs $16.25 USD and you can pay by Paypal.

Take a look:- http://www.porting-programs.com/

Calculates port heights port durations and shape based on port time areas as defined by Jennings and Blair for a desired rpm operating range.

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[TZ350]

From:- http://drunkmunkey6969.googlepages.c...210vspolini210

Transfer ports....its something we come back to again and again on Vespa and Lambretta scooters. In comparison to modern design, the transfer ports are the biggest let-down of scooter engine design. By enlarging the surface area of the transfer ports (see porting work on side and boost transfers above) and also cutting away a portion of the cylinder wall.....we can vastly increase the performance of the kit.

A cagiva 125 cylinder next to a Malossi cylinder, merely to illustrate how modern 2-stroke design incorporates massive ports and transfers as part of their standard production performance. Those sider transfers must be at least 4 times as large as the Malossi!

If top Scooter performance is your goal....then the cases must be ported. Its just common sense. A past article in Scootering magazine demonstrated (using a dyno reading) that merely bolting on a Malossi 210 cylinder, with no other alterations (other than jetting and timing) only gave a 2bhp improvement....but with additional porting and an expansion chamber, it gave approx 9bhp extra than standard!

Also, as mentioned earlier, the cylinder and casings can be ali-welded to build up new surface area, and then carve out massive race-style transfer ports, this is quite a time consuming task, but the results are fantastic.

The five'th pic is of the case transfers of a Honda RS125.

I can now see why SS90 was so keen on "unmasking the transfers" but it looks like Bike development is allready way ahead of Scotters.

Last Pic. Top Left: Standard Mallossi 210, Top Right: MB Developments 225 TS1 - stage 2 road/race, Bottom Left: Cagiva 125 cylinder for comparison, Bottom Right: Sean Brady 'wild race' 225 TS1 - work in progress.

The pictures say it all really.
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[Bren_chch]

thanks for all the pdf files, good reading.

[TZ350]

From:- http://drunkmunkey6969.googlepages.c...workinprogress

Check this out, Sean has been working on this totally 'balls out' race porting for one of his Lambos....

The pictures below show what is basically a 'work in progress' but you get the idea of what is going on!

If you compare the transfers of a standard Cagiva 125 cylinder, to the race porting Sean is working on....you'll see where the idea comes from!......................................

In a reply to SS90 F5Dave said:-

Since the dawn of time people have been adding more transfer ports, often fed by the piston with holes near the top. This does smack of a compromised transfer arrangement. To put them in the main transfers more so.

I suspect this is borne of your typical scooter having a very compromised crankcase design affecting where you can place & feed transfers......................................... ....

I can now see what he meant. Looks like the Scooter boys get their best insperation from current Bike technology.

I had hoped SS90 was onto something new with his talk of unmasking the transfer ports but it does not look like it. Still those big bore, stripped down racing scotters with 30HP go fast and look mean.

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[speedpro]

That huge intake port would cause me to be concerned about piston support. Skirts could end up cracking which is why my intakes are like they are - area with support.

[bucketracer]

Looks like SS90 the super scotter tuner is mistaken about how much he knows and had to offer.

[TZ350]

That huge intake port would cause me to be concerned about piston support. Skirts could end up cracking which is why my intakes are like they are - area with support.

Below they talk about the overly wide inlet and how improving the transfers allows a smaller inlet/exhaust port and also how Japanese bikes are on the money.

From:- http://drunkmunkey6969.googlepages.c...ylinderporting

Pic 1. Inlet port on the all out race cylinder is colossal in comparison to the stage 2 cylinder on the left. This will lead to awesome all out performance....but due to the decreased life of the piston and rings, its not the kind of thing you'd do 12,000 miles worth of touring on!

Pic 2. On the left, these transfers really help to increase the power dramatically, but without the wear problems associated with oversized inlet and exhaust ports. Which is why so many jap bikes have fantastic transfer port set ups these days.


Guess what I race??? I recon I am on the right track.

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[SS90]

Looks like SS90 the super scotter tuner is mistaken about how much he knows and had to offer.

Oh dear, it just keeps getting better...

For your information.... the pictures of the Vespa engines (and transfers) are from a "big Frame" Vespa, and totally different to a "small frame Vespa"

The design of which is not too dissimilar to a modern single cylinder Japanese engine (well, in terms of layout anyway)

The picture I have attached is of the transfer areas of ONE of my over 25 Hp Engines..... I make these for a living.