Revolutionary boxer engine

[ckissick]

I don't know if this is a repost, but:

Home | EcoMotors

[krystar]

revoluntionary....yea. so it's a opposing 2 stroke. how do they make a 2 stroke emissions friendly? and the animation shows no spark plug...so it's a diesel. but they say in the text it's diesel, gas, ethanol. so are they just dieseling gasoline in the engine?

[widebody911]

The E-Ram is dead; long live the E-Ram

[red-beard]

Originally Posted by widebody911

The E-Ram is dead; long live the E-Ram

THAT isn't an E-RAM. When ERAM and SON of ERAM threads were going on, I found 2 or 3 REAL electric superchargers. They required a LARGE battery system, which was good only for short bursts of Super-charging. They were set to activate at WOT only.

Turbo-super charging is great since it uses otherwise wasted energy to compress the intake air. The electric super charger might be a great way to maximize highway accelleration, etc, while keeping an engine small, light and uncomplicated.

[Zeke]

Exhaust gas turbo charging on a 2-cycle would not be efficient. I wonder if a mechanical blower would be good.

[gtc]

AFAIK, the opposing piston opposing cylinder design has been around for a while, but nobody so far has been able to get it to run well or reliably.

[wdfifteen]

Originally Posted by milt

Exhaust gas turbo charging on a 2-cycle would not be efficient. I wonder if a mechanical blower would be good.

Like a Detroit? They made millions of them, so you could say they were popular, if not good. The 6-71 was the most popular because its blower was adapted to a lot of drag racers. I had a John Deere 435 with a Detroit 2-53. Bulldog of a little tractor. I watched a 16 mm film made back in the 40s that showed a 3-71 running. They shut it down and took the inspection plates off to reveal that the rods didn't have any caps on them. The pressure in the cylinder was always positive enough to keep the rod seated on the crank.

[gtc]

My buddies boat has a 6-71.... noisiest thing ever... i wish it would just die so I can get him a Cat, but it taunts me by firing right up every time.

[Shawn 357]

That thing could probably run pretty high RPM's with the lack of valvetrain... I wonder how slow revving it would be with basically two pistons and three connecting rods per cylinder.

[Zeke]

Originally Posted by wdfifteen

Like a Detroit?

Or a Paxton.

[wdfifteen]

Originally Posted by gtc

My buddies boat has a 6-71.... noisiest thing ever... i wish it would just die so I can get him a Cat, but it taunts me by firing right up every time.

Yeah, they're noisy and thirsty, but dirt simple and almost bullet proof. The basic design is symmetrical so you can change the direction of rotation and/or move the blower to the other side and/or move the drives to the other end if you have another use for the engine.

[sammyg2]

Originally Posted by milt

Exhaust gas turbo charging on a 2-cycle would not be efficient. I wonder if a mechanical blower would be good.

I've looked into this in the past. Turbocharging a conventional 2 stroke gasoline engine would be very difficult.
Both theoretically could be made to work but both would have engineering limitations.

An exhaust driven turbo on a 2 stroke could pose problems due to back pressure, but it's all relative. Delta P.
the intake charge forces the exhaust out of the cylinder. Increase the intake pressure and it mostly compensates for the increase in back pressure.
If you increase the intake pressure that would also help to evacuate the exhaust overcoming the resistance from the turbo.
The problem with that would be the turbo efficiency. Most turbo compressers are only about 55% efficient. So if it was putting out 7 psig boost, it could take up to 10 psig of exhaust pressure to spin it. that means the cylinder would not be evacuated very well.
A 2 stroke diesel works because of the very high compression and boost levels, and having some left over exhaust in the combustion chamber actually helps ecomony and the dieseling process. Sure it robs horsepower but as long as it is controlled it is an accepted trade-off. Conventinal intake valves also help.

Serious port timing modifications would be necessary on both types of systems to prevent large amounta of unburned air/fuel from going out the exhaust and it might require computer-controlled variable exhaust ports to make it work well (slide valves) but it is do-able.
The other issue would be sealing the case.
Most two stroke cases are not designed to contain positive pressure (above atmospheric). That would have to be addressed, a mechanical seal on the crankshaft would probably take care of that.
The reed valves would probably have to be modified also.

It would definately not be a bolt on type of thing.

[sammyg2]

Originally Posted by gtc

My buddies boat has a 6-71.... noisiest thing ever... i wish it would just die so I can get him a Cat, but it taunts me by firing right up every time.

I ran a GMC blower on a chrysler hemi in my drag boat.
Most of the noise is due to the straight or semi-straight cut gears that drive the lobes.
if they had room for a true helix or a double helical gear it would be much quieter.

Straight cut gears are much more efficient as far as power transmission goes but they make alot of noise and vibration.

think of it as a slap vs. a slide. Straight cut gear teeth hit each other all at once and the oil film is all that keeps them from going metal to metal. They also require a little more back lash (usually, not always).

Helical gear teeth mesh more gradually. Kinda like hitting a speed bump at an angle instead of head on. The downside to helical gears is thrust.
The angle creates opposing axial forces and must be dealt with by larger, heavier
bearings. That creates added friction and heat.

Also, most high performace blower applications have wide open intake tracts. No sound deadening or baffling. That makes blowers loud too.

[LakeCleElum]

Originally Posted by milt

Exhaust gas turbo charging on a 2-cycle would not be efficient. I wonder if a mechanical blower would be good.

Milt - I always thought this way, especially when I road raced 2-stroke motorcycles and did my own porting.

BUT, in the last few years, the snowmobile crowd has had great success with 2-stroke Turbos....The old issue was wasting the fresh charge out the exhaust, but good design of expansion chambers solves this.

Currently getting 250/hp out of .8 liter engines (800cc). Pretty fast in a 500 lb package...Race gas is a must due to the high compression. Also, compression/heat change with temp and elevation making tuning very critical.

[john70t]

Angel Labs :: News claims 850hp out of a 150lb engine!
The demo was back in 2005, so either there were some technical complications and/or a lack of funding.