I found this pretty interesting.
http://pixelbark.com/13045/how-the-...-efficiency-of-the-internal-combustion-engine
http://pixelbark.com/13045/how-the-...-efficiency-of-the-internal-combustion-engine
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A future O-320/360?
- Thread starter Hack
- Start date
Dyna-Cam flew a similar engine around Chino California for a number of years. Axial Engines are not a new idea. There has been at least 100-years of development and we still do not see many in actual use.
I'm a big fan of ported (sleeve valve) type engines. Right now, the Wankel Rotary seems to be the sole survivor of the type.
Removing the poppet valve from the intake & exhaust ports increases volumetric efficiency and reduces pre-ignition / detonation.
Sealing is always a problem.
In this case, the cylinder-to- head joint is a sliding face.
On a Lycoming, this is a screwed together shrink fit joint. On your car it's a bolted joint with a gasket.
The Duke head gasket is going to look something like a piston ring, be held in the top of the cylinder block, and slide along the face of the head. The force of combustion will work to separate this joint, so the running clearance must be controlled.
This means lubrication and sealing will be a challenge.
Also, this engine will be water cooled, yet cylinder cooling won't be via water jacket, the cylinder is spinning.
It might have a hard time passing emissions testing, as it might use oil along the head 'gasket' seal.
If successful, the disadvantage of the Wankel type (high surface area to volume ratio in combustion chamber) would be laid to rest, and fuel efficiency could be very good.
I hope they do well.
Removing the poppet valve from the intake & exhaust ports increases volumetric efficiency and reduces pre-ignition / detonation.
Sealing is always a problem.
In this case, the cylinder-to- head joint is a sliding face.
On a Lycoming, this is a screwed together shrink fit joint. On your car it's a bolted joint with a gasket.
The Duke head gasket is going to look something like a piston ring, be held in the top of the cylinder block, and slide along the face of the head. The force of combustion will work to separate this joint, so the running clearance must be controlled.
This means lubrication and sealing will be a challenge.
Also, this engine will be water cooled, yet cylinder cooling won't be via water jacket, the cylinder is spinning.
It might have a hard time passing emissions testing, as it might use oil along the head 'gasket' seal.
If successful, the disadvantage of the Wankel type (high surface area to volume ratio in combustion chamber) would be laid to rest, and fuel efficiency could be very good.
I hope they do well.
I like the concept - what kept this engine from coming to market?
skylor
Well Known Member
Large rotating mass
Besides the cylinder sealing concerns already mentioned, another issue that I see with this type of design is that they have a rather large rotating mass with a decent moment of inertia. This could cause gyroscopic issues as well as slow response to power changes.
Skylor
Besides the cylinder sealing concerns already mentioned, another issue that I see with this type of design is that they have a rather large rotating mass with a decent moment of inertia. This could cause gyroscopic issues as well as slow response to power changes.
Skylor
Neal@F14
Well Known Member
Lawsuits on the outside and mechanical problems with bearings on the inside?
http://www.aafo.com/hangartalk/show...ed-to-the-Dyna-Cam-engine&p=103356#post103356
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I don't see how the next inovation in engines will include reciprocating pistons. Very poor performance with having to take all that piston and rod inertia and turn it around in direction every piston and RPM. Wankel was headed in the right direction. We also use Scrolls in A/C compressors now to eliminate the reciprical motion.
Not so new an idea 
http://www.aqpl43.dsl.pipex.com/MUSEUM/POWER/unusualICeng/axial-ICeng/axial-IC.htm
(BTW, this site has some extraordinarily interesting pages...be prepared to get sucked into a real time sink if you start exploring it Here's the top-level link
http://www.aqpl43.dsl.pipex.com/MUSEUM/museum.htm)
http://www.aqpl43.dsl.pipex.com/MUSEUM/POWER/unusualICeng/axial-ICeng/axial-IC.htm
(BTW, this site has some extraordinarily interesting pages...be prepared to get sucked into a real time sink if you start exploring it
Here's the top-level linkhttp://www.aqpl43.dsl.pipex.com/MUSEUM/museum.htm)
One of the unfortunate things about development like this, is that with a 30% weight reduction, either your RV is going to look ridiculous with an extra foot on the nose, or you're going to be carrying ballast in the cowling to maintain the look.
In order for it to take off, as it were, you'd need a whole new airplane designed around it, or you need to design an engine that weighs the same as an O-320 or O-360. Never mind making it more efficient, make it just as efficient, and just as reliable. And prove that it is beyond a shadow of a doubt.
Without that, all of these alternatives will languish in obscurity until Lycoming pulls the plug on production.
In order for it to take off, as it were, you'd need a whole new airplane designed around it, or you need to design an engine that weighs the same as an O-320 or O-360. Never mind making it more efficient, make it just as efficient, and just as reliable. And prove that it is beyond a shadow of a doubt.
Without that, all of these alternatives will languish in obscurity until Lycoming pulls the plug on production.
