OVAL Piston?

[Jekyl_22]

Did anyone else read about the oval piston in the new ATV Action? They were talking about how it's a possiblity that honda may use it in their new four-wheeler....(not getting hopes up...)

[Narly R]

Ya know come to think about it I acually say that! I wonder if its true..............:confused:

[Jekyl_22]

Yeah, well.... I was just going to weld two pistons together, take a dremmel to my cylinder, and call her good! I hear all the pros are doing that these days.:eek2: But seriously, thaty said comething about power of 2 stroke and 4 stroke.....lots of stuff. Don't really believe the power part of it. If it has the power of a 2 and 4 stroke, you could just average it and call it a 3 stroke.:rolleyes: I know a kid that claims he has a 3 stroke! I bet he is telling the truth....:huh

[dj416]

that thing looked wild, good look trying to find a machine shop to bore it and hine it for the big bore kit:confused: probly honda's way to get u to buy a new jug and piston from them when it comes time for a rebuild:grr:

[Narly R]

Ok since Im dumb what is the differance (or how will you get more power) from a oval piston than that from a regular one?:confused:

[dj416]

more displacement. more compression. stronger cause it uses 2 connecting rods on one piston. fuil will probly atomize better in the combustin chamber. it will be like an 8 valve 1 cylnder. 2 sides of the cylnder are flat, not curved like a round hole, so it will probly not wear out as fast, its kind new 2 me too. thats just what i think, i'm not sure tho

[Narly R]

ok I think I understand....................:confused:

[Juggalo]

ya know there is such a thing as a 3 stroke engine. its a twin cylinder and one cylinder is a 4 stroke and the other is a 2 stroke. together its a 3 stroke. no lie. its on the net somewhere. also there is an 8 stroke engine.

[Guy400]

I'm not saying it's impossible but I'd really be surprised if Honda released their newest piston technology in one of their quads. You'd see it in their dirtbikes or streetbikes first.

[hondafox440]

The reson behind it is probably so they can run an OHC without rocker arms, thus having less reciprocating and revovling mass, and still have the 'correct' port size and port area for maximum low end power and top end power. The rev ceiling on an engine like is theoretically much higher than any thumper out there now, and I would bet it would be upwards of 20,000RPMs.. But, there is a point of diminishing returns, where it makes no sense to rev higher do to the heat and friction created. The cooling system on an engine like that should be interesting, maybe a combo air cooled and liquid cooled..

Did any of this make sense or am I rambling?

[hondafox440]

Originally posted by Juggalo
ya know there is such a thing as a 3 stroke engine. its a twin cylinder and one cylinder is a 4 stroke and the other is a 2 stroke. together its a 3 stroke. no lie. its on the net somewhere. also there is an 8 stroke engine.

I dont see how a 3 stroke would work, let alone be efficient. Although, on 2nd thought, you could use the power stroke of the 2 stroke to help the compression stroke and exhuast stroke on the 4 stroke, and vice versa. But it would be difficult to get everything timed correctly..

[crazy canadian]

my dad has a patent on an oval shaped piston he designed for proffesors at the university of massacusets. It was to be used in a steam engine they were prototyping. I believe they had intensions of putting it in personal watercraft.

[hondafox440]

Bump, this could make an interesting debate..

[TagRider]

Hondafox, where you get an oval piston would allow for 20,000RPMs? Formula 1 cars only turn 18,000RPMs and they're using magnesium/beryllium alloys in the reciprocating assembly for the epitome of weight savings. Even if Honda was to go to an oval piston we're still talking a single cylinder displacing (guessing) 450cc's. You'll still have to whip a crank around and just from what I read here but there's going to be 2 connecting rods. That's double the weight right there to throw around. This is also in conjunction with stock Honda internals. They're certainly not going to install $10,000 beryllium crank and rods in the new quad.

[MCSS]

There is also a design of a 6 stroke engine. It has no valves which could get it more revs. It could be coming into sport bikes like Ducati in the near future. There web site is at sixstroke.com

[Dan_Guetter]

thats some crazy stuff!!!

[hondafox440]

Originally posted by TagRider
Hondafox, where you get an oval piston would allow for 20,000RPMs? Formula 1 cars only turn 18,000RPMs and they're using magnesium/beryllium alloys in the reciprocating assembly for the epitome of weight savings. Even if Honda was to go to an oval piston we're still talking a single cylinder displacing (guessing) 450cc's. You'll still have to whip a crank around and just from what I read here but there's going to be 2 connecting rods. That's double the weight right there to throw around. This is also in conjunction with stock Honda internals. They're certainly not going to install $10,000 beryllium crank and rods in the new quad.

I didn't say the Honda would turn 20,000RPMs, I said the engine would most likely be capable of it. With a single OHC and no rocker arms the rev ceiling will be substantially higher than a normal OHC or DOHC engine, because of the small amount of mass turning on the cam train. Formula 1 cars are 8 cylinder, DOHC engines, correct? If you can get a DOHC to rev that high (I thought they redlined at 13,000 not 18, but whatever), half of that mass means higher rev ceilings. Its all theoritcal, but I think its feasable..

[ROGERS]

They have run oval pistons in road race bikes before. It was years ago, though. Old tech.:ermm:

I have also seen pictures of a V-3, 2/4 stroke bike. Front 2 are 4 stroke and the rear is 2. I think it was fake though.

As some one mentioned F1 earlier, if you want to see the technology that will be coming our way in the future look into F1 and MotoGP. Those are the tech playgrounds.

[airheadedduner]

Originally posted by Guy400
You'd see it in their dirtbikes or streetbikes first.
God I am glad my memory is not completly gone. I couple years ago I found an old popular mechanics that my HS shop teacher had layin around. It had an article on a honda street bike with oval pistons. It reved out beyond 18,500 and made an insane amount of power. I don't really remember the specs but they abandond the idea because it was very unreliable, it never completed a race. I think it was a 600cc range bike that was a factory racer.

[MOFO]

Originally posted by Guy400
I'm not saying it's impossible but I'd really be surprised if Honda released their newest piston technology in one of their quads. You'd see it in their dirtbikes or streetbikes first.


I agree with ya, but they might be using this wild setup on the quad market first (real world R&D) before they use it in their larger "more important" markets. :D

[CBus660R]

Honda did build an oval pistoned streetbike in the late '80s, the NR750. It was originally designed for racing, but did not work out well and never even raced. The problem was getting good ring seal. A very limited production run was made (10 or 20 I think) and they sold for something like $30k-40k, available only to customers with a close working relationship with Honda. The theory behind it was to get more valves in the head to allow for better air flow. It would breath like a V-8 even though it was only a V-4. The only reason they tried it was because 4 cylinder engines were the most allowed by the rules, otherwise they would have just made it a V-8. As a side note, F-1 engines are V-10s with pneumatic valvetrains, meaning there are no cams, rockers, or springs, just little air fittings to open and close the valves. That is why the idle speed on an F-1 engine is close to 10,000 RPM (to run the onboard compressor to work the valves) and the redline is in the 18,000-19,000 RPM range. Here's a link to one that's for sale (a Euro is worth about the same as a dollar, maybe a little more) NR for sale (http://www.bikez.biz/ads/showad.php?ad=1607)

[Ralph]

how the hell do u bore ur cylender then? might be tricky?

[hondafox440]

You dont.

According to a few suites I found, the NR750 was made in 1992 and had state of the art EFI, and pounded out 150bHP. Thats quite a bit, especially for 1992, considering an 03 RC51 with Yoshi pipes dynoed at 124HP at the wheel (saw the run in person)..

what does bhp stand for ? bullchit horsepower?

[hondafox440]

It means brake horsepower, or the horsepower at the driveshaft.