Who says honda never test FI 2 strokes

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10/26/2018 1:21 PM
Edited Date/Time: 10/26/2018 1:23 PM

I found this pic of a HRC engine I'm sure it was a later model 250 v-twin GP bike. Was it ever used in racing not sure. Is that a pneumatic operated power valve?

Photo

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10/26/2018 1:30 PM

B'Dass

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10/26/2018 1:35 PM

Marty Smith’s first gen RC125 had engine cases that were cast to accept fuel injection.

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10/26/2018 3:55 PM
Edited Date/Time: 10/26/2018 3:58 PM

Honda EXP-2

55hp fuel injected 400cc two-stroke. Honda raced Dakar and Baja with it in '95.




Photo


[LINK TO IMAGE]

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10/26/2018 6:19 PM

Honda tested FI back in the 1990’s GP500 days on their V4 500’s I don’t know if they ever raced them successfully. I also read somewhere that they tried using water to create steam in their expansion chambers to smooth out the powerband and add some bottom end. Honda probably has done more 2 stroke development than any manufacturer. But they were always a 4 stroke corporation.

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10/26/2018 6:46 PM

They never test FI 2 Strokes. (Present tense)

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James

10/26/2018 7:40 PM

Honda has some nice SAE papers on the FI subject.

They tested heavily! But solving the EFI issues - to this day - hasn't really happened.

I think honda's "smart" 2t guys were gone by mid 90s (with all their hard work accomplished far earlier. Be it retirement - or better opportunities or even transition to 4t side of honda - but their later stuff had a few flaws that was worse in areas than the previous generation (with improvements on "paper" - that could have panned out)

That dakar engine was ultra trick - to this day would be cool in the 2t world.

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10/26/2018 8:09 PM

The Honda 500 GP road race bike was injected and worked great as a matter of fact it was the best GP engine in the field.

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10/26/2018 11:24 PM

In 1993, an important technological breakthrough took place when electronic fuel injection was implemented. With two injectors per piston and an ECU which was capable of managing the supply’s optimum functioning. This system made it possible for Sinichi Itoh to become the first pilot that achieved speeds of over 320 km/h. In spite of this success, there did not seem to be significant improvements in comparison to traditional carburettors, so the entire system was dismissed.

Even though the 1994 season saw no major changes, towards the end a water injection system was incorporated to the exhausts which improved performance in the mid-range of revolutions. An extra 10 hp were achieved in the range between 6000 and 10 000 rpm when the temperature of the combustion chambers was modified. Doohan decided against this improvement and instead chose a more conventional engine, since the bike was already sufficiently hard to handle. Doohan finally managed to win the World Championship on this machine, making it evident that the NSR500 development was reaching its peak.

In 1995, carburettors over 39 mm were installed, significantly improving performance. Thanks to this tweak, and a stronger than ever Honda team, Doohan won his first two World Championships for the Repsol Honda Team in 1995 and 1996.
https://www.boxrepsol.com/en/technology/the-honda-nsr500-engine-evolution/

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10/26/2018 11:33 PM

Honda sent the competition’s engineers scrambling to catch up to the NSR’s Big Bang engine back in ’92; two seasons later, no one has succeeded. In ’93 the Big H introduced fuel injection to the 500 class, and at Hockenheim Shinichi Itoh became the first GP rider to break 200 mph. Again the paddock was abuzz with talk of the peak power advantages of fuel injection. But Hattori reveals other motives: “The benefit of fuel injection is an improvement in fuel economy of five to 10 percent, therefore we can reduce fuel weight carried at the start of race.” Hattori claims that the injection system didn’t yield a horsepower advantage. When questioned as to why Itoh’s bike was six miles per hour faster than Doohan’s carbureted bike at Hockenheim in ’93, he claimed that the smaller Itoh was able to tuck in tighter (due in part to Doohan’s leg injury as well). For ’94, Itoh ran fuel injection only during the first two GPs, reverting to carburetion thereafter.
Riding Mick Doohan's Honda NSR500

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10/27/2018 12:23 AM
Edited Date/Time: 10/27/2018 12:30 AM

Mit12 wrote:

The Honda 500 GP road race bike was injected and worked great as a matter of fact it was the best GP engine in the field.

The only HRC rider that raced with the 'FI' 500, was the Japanese rider. Not sure of the name, but it might have been Itoh.

Doohan, etc, apparently, didn't. Most Top Level Riders are rather conservative - they want what they've won on before, plus a few percent. Though, Doohan played 'games' with his rivals, when it came to bike / engine usage. The FI 'd 500 was, apparently, quite a savage beast, and it reputedly, sent a fair few riders 'sky high' with even more vicious high sides than was the 'norm' in those days. Doohan might have been on the wrong end of one of those, during testing.

Honda has probably more 2t tech locked away in their archives than all the other manufacturers combined. But, it's locked away, never to see daylight. More or less 'design exercises' that they got through letting their engineers flex their 'muscles' with. And, they probably still are doing 2t research, today. They did make use of some of the aspects of the EXP2 - the Activated Radicals / Trapping Valve side of it, with the CRM250AR. The 400cc 2t EXP had about 12 - 15HP less than the Works V Twin 780cc 4ts, the same Torque, and weighed about 100lbs less, reputedly. And, used less fuel.

But, Honda is : "All Fourstroke, All The Time". Well they always were until the 70s Dirt Bike Boom came along, and they wanted a slice of the action, with their (rogue engineers) 'lawnmower project'. And their NR500 Oval Piston, 8 valves per cylinder , with twin conrods per piston bike was a racing failure when they returned to the Road Race GPs. Though, they learned a hell of a lot from it. They then turned to 2 strokes, to win, until they got rules to their suiting.

I'd written this before Underground put his article copies up, but hadn't posted it. So I got 'Itoh' right. My neighbours came in with some beers before my trip to Singapore tomorrow, and I downed a few. I'm going over for a mates Wedding, and he's got perfect timing, as I'm doing the 1 hour flight up to KL Airport next Sunday, for the Sepang MotoGP. The tracks about 1.5ks away from KL Airport. Flights and ticket for the race ad up to less than $200, so it would be silly not to go!

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10/27/2018 1:10 AM

Ebs wrote:

Honda EXP-2

55hp fuel injected 400cc two-stroke. Honda raced Dakar and Baja with it in '95.




Photo


[LINK TO IMAGE]

Back in the day, they had nice stickers printed with the slogan "EXP-2, friendly to earth and nature".
I remember 'cause I put one on my... CR 500 rear fender.
wink

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10/27/2018 1:16 AM

Bearuno wrote:

The only HRC rider that raced with the 'FI' 500, was the Japanese rider. Not sure of the name, but it might have been Itoh.

Doohan, etc, apparently, didn't. Most Top Level Riders are rather conservative - they want what they've won on before, plus a few percent. Though, Doohan played 'games' with his rivals, when it came to bike / engine usage. The FI 'd 500 was, apparently, quite a savage beast, and it reputedly, sent a fair few riders 'sky high' with even more vicious high sides than was the 'norm' in those days. Doohan might have been on the wrong end of one of those, during testing.

Honda has probably more 2t tech locked away in their archives than all the other manufacturers combined. But, it's locked away, never to see daylight. More or less 'design exercises' that they got through letting their engineers flex their 'muscles' with. And, they probably still are doing 2t research, today. They did make use of some of the aspects of the EXP2 - the Activated Radicals / Trapping Valve side of it, with the CRM250AR. The 400cc 2t EXP had about 12 - 15HP less than the Works V Twin 780cc 4ts, the same Torque, and weighed about 100lbs less, reputedly. And, used less fuel.

But, Honda is : "All Fourstroke, All The Time". Well they always were until the 70s Dirt Bike Boom came along, and they wanted a slice of the action, with their (rogue engineers) 'lawnmower project'. And their NR500 Oval Piston, 8 valves per cylinder , with twin conrods per piston bike was a racing failure when they returned to the Road Race GPs. Though, they learned a hell of a lot from it. They then turned to 2 strokes, to win, until they got rules to their suiting.

I'd written this before Underground put his article copies up, but hadn't posted it. So I got 'Itoh' right. My neighbours came in with some beers before my trip to Singapore tomorrow, and I downed a few. I'm going over for a mates Wedding, and he's got perfect timing, as I'm doing the 1 hour flight up to KL Airport next Sunday, for the Sepang MotoGP. The tracks about 1.5ks away from KL Airport. Flights and ticket for the race ad up to less than $200, so it would be silly not to go!

It was Shinichi Itoh. It was the fastest bike through the speed trap in, I think, 92. Doohan refused to ride it because it had a nasty habit of locking up. The very last NSR500, the Nastro one Rossi raced, had four dual throat carburettors and a gigantic fuel tank.

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10/27/2018 1:51 AM

GP and F1 development that has been let out of the bag definitely makes for interesting reading. For me anyway

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