ESE's works engine tuner

[husaberg]

No idea but i have recall tales Honda (or more likely i assume Jeremy Burgess) once anonymously gifted bank of works Honda nsr Keihin carbs in to help Patton. I think that was mentioned in a TDC?

I don't know about Paton; I understood that Honda gave a Keihin set to keep Cagiva in the game. As did Yamaha: they gave Cagiva a complete Yamaha TZR500 bike on loan for a month. I happen to have the works drawings (don't ask how or why, in Italy anything is possible ).

In regards to at least the carb story it was actually the then head of HRC and it was three sets of carbs to Paton I also never knew it had a 1993 Cagiva frame though.

pg 97 i gave up trying to attach it after 20 attempts


https://magazine.cycleworld.com/arti...e-tt-centenary

paton is a family business based near Milan, Italy. As a manufacturer, it scored points in GPs as early as 1966 and competed from 1975, allegedly without interruption, until 2001. That was when the new four-stroke rule and the associated expense forced them to concentrate on a brand-new classic racer (an oxymoron, I know, but they make spec vintage racers from scratch). Linsdell and his son Ollie normally race air-cooled, four-stroke 500cc Paton Twins, but Steve wanted one of the strokers that lined up on the same grid, albeit at the rear, as Valentino Rossi, Max Biaggi and Loris Capirossi back in 2000.Amazingly, everyone agreed, and the bike that turned up behind the TT Grandstand is the PG500RC, the most wonderful GP mongrel. The frame and swingarm are modified 1993 Cagiva C593, as raced by John Kocinski, Doug Chandler and Mat Mladin. It is the only two-stroke Paton that doesn’t have a Paton frame.


The engine is Paton, built with a keen


recycler’s ingenuity. It is a 70-degree V-Four, with a big-bang firing order. The cases are sandcast magnesium. Barrels are Swissauto while the bores house Honda RS125 pistons that have had their crowns turned off in a lathe. Ignition and ECU are by Walbro.


Roberto Pattoni, the son of one of the company founders and chief mechanic for the TT effort, tells a story about when Paton was competing in GPs. At the time, the then-boss of HRC, Youichi Oguma, was interviewed and said, “Everyone should have a passion like Paton. I would


like to help them if I could.” Paton didn’t need a second invitation and said, “If you’d like to help us, you could sell us some of those top-secret magnesiumbodied Keihin carburetors your NSR runs so well on.” In 1993, those carbs cost $25,000 for a set of four. “They cost that much because they didn’t want anyone to buy them,” says Pattoni. A week later, a box arrived from Japan with three sets of carbs, free of charge. One bank of four is on this bike.

[Maxdelta]

Thanks Wobbly. I asked about a "rule of thumb" for single port intakes because i do know there are some that run the single port without a bridge. An example is Yamaha SRX440 snowmobile cylinder. It has a single port. See pic

[TZ350]

.


An interview with Dane Rowe, a hottie from the 60's

https://rocinantemecanico.blogspot.c...with-dane.html

[F5 Dave]

What was that original pic Max? Not an RM250 as obviously oil injection. So guessing RG250. 1/2 Reed barrel so you don't need monster inlet area and you can get heaps normally. I'd concentrate on anything else.

Like re-engineering the crank to use better rods if you want to rev it a bit more.

[wobbly]

Max, even in that pic you can see that the inlet is a way narrower chordal width than the Exhaust.
As I said this is due to the rod angularity pushing the skirt into the bore as the piston approached IPC.
Having a bridge helps this immensely, allowing the two ports to be much wider at the top.

[Maxdelta]

What was that original pic Max? Not an RM250 as obviously oil injection. So guessing RG250. 1/2 Reed barrel so you don't need monster inlet area and you can get heaps normally. I'd concentrate on anything else.

Like re-engineering the crank to use better rods if you want to rev it a bit more.

Dave,
Its a Suzuki snow cylinder (Arctic Cat 580).

[Maxdelta]

Thanks Wob,
This cylinder has the C ports ducts that are fed right along the outside of the intake port, so there is minimal meat there to widen the port. Also, no room left to lower or raise the port. Hence my looking into the possibility of removing the bridge. The stock bridged intake port width is ~68% of bore. Maybe there's not much left that can be done to this port? I could square off the bottom corners to gain some more area, and I can widen approx. 1mm per side.

[wobbly]

Depends on how the intake STA sits in comparison the the Blowdown , and the amount you would gain by increasing the Intake duration ( cut the skirt ) - against loosing bottom end.
Use JanBros spread sheet and analyze the ports.