Add Peripheral Exhaust Port To Renesis

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Lendo

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Sorry Dwalker I should have said small PP intake port with side ports. What you seem to be missing is the side intake and exhaust ports are restrictive due to the nature of the ports themselves, they may well be oversized for this very reason; however PP provide a straight-in and straight-out route i.e. no restriction due to the shape of the port and travel path the air must take, improving Inlet Velocity and and therefore Volumetric efficiency and that is why they can produce more power. Sweeping unburned fuel into the next combustion event is great for environmental pollution reasons, but not great for power. It basically depends upon what sort of power you want in which direction you want to go.
For straight out efficiency PP is the way to go, the biggest hurdle is having a reliable port that doesn't leak coolant into the combustion chamber, this can be achieved with an imaginative design for IP reason I can't comment further -sorry.
George
 

dwalker

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Sorry Dwalker I should have said small PP intake port with side ports. What you seem to be missing is the side intake and exhaust ports are restrictive due to the nature of the ports themselves, they may well be oversized for this very reason; however PP provide a straight-in and straight-out route i.e. no restriction due to the shape of the port and travel path the air must take, improving Inlet Velocity and and therefore Volumetric efficiency and that is why they can produce more power. Sweeping unburned fuel into the next combustion event is great for environmental pollution reasons, but not great for power. It basically depends upon what sort of power you want in which direction you want to go.
For straight out efficiency PP is the way to go, the biggest hurdle is having a reliable port that doesn't leak coolant into the combustion chamber, this can be achieved with an imaginative design for IP reason I can't comment further -sorry.
George
This is why I advocate for the standard 13B-REW with Renesis rotating assembly.

Also I disagree with the PP being more efficient than the side intake ports. It *can* make more power, but at the expense of low and mid-range power and all economy. I am aware that some (Rob Golden from Pineapple for example) have managed to build street driven PP rotary engines, however, they were still a study in compromise.

Now if I had an engine development lab and a massive pile of money to spend making one-off parts, testing, then repeat, it is entirely possible a variable length and volume intake manifold could make the PP usable, but I do not have such things, and currently there is almost zero interest in the commercial use of it.

I will note that the UAV companies apparently did get full PP motors to work fairly well, but most of thier work and findings are also apparently super secret squirrel stuff that mere mortals are not privvy to.
 

Lendo

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dwalker, you are probably aware the Original Powersport partners did recognize the low rpm roughness and controlled that with a butterfly in the housing. it seems the closer you can get to the inner port the better the results - however there are better approaches than that.

Urquiola I went down that road of a single Rotor, you can cut the power down by half but not the overall weight and there is the additional Eccentric shaft manufacture, rotor oiling issue, loss of the rocking couple with balancing issues, the list goes on. Better to buy Aluminium end and middle housings.
George
 

rv7charlie

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Nov 17, 2014
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Pocahontas MS
What George just said about custom fab of parts obviously applies in principle to swapping out the rotating assy, P-porting, etc etc.

Most of us (Don excluded, of course), if we're honest with ourselves, are walking the 'skillset edge', just to get a stock core engine to a state where it's usable in an a/c. While the rotary is technically dirt simple, and technically capable of prodigious HP numbers, wandering away from stock config and especially trying to extract more than stock HP is a high risk endeavor for us. As much experience as Tracy had with the rotary, he bought both his Renesis core and his 20B core from an established rotary engine builder with a strong reputation for quality builds. No doubt some of that choice was simply time saving, but knowing that the core will 'just work' is worth a lot, especially when so much around it must be changed for a/c use.

I have little doubt that a P-intake Renesis with reduced-diameter P port 'timed' later to minimize overlap would be lighter (simpler intake), produce more usable power than a stock Renesis even in the lower rpm range (5k-7k rpm), and would be quieter/less offensive in sound than a 13B, but it won't be the 1st rotary I fly, because Dirty Harry was right.

Charlie
 

dwalker

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What George just said about custom fab of parts obviously applies in principle to swapping out the rotating assy, P-porting, etc etc.

Most of us (Don excluded, of course), if we're honest with ourselves, are walking the 'skillset edge', just to get a stock core engine to a state where it's usable in an a/c. While the rotary is technically dirt simple, and technically capable of prodigious HP numbers, wandering away from stock config and especially trying to extract more than stock HP is a high risk endeavor for us. As much experience as Tracy had with the rotary, he bought both his Renesis core and his 20B core from an established rotary engine builder with a strong reputation for quality builds. No doubt some of that choice was simply time saving, but knowing that the core will 'just work' is worth a lot, especially when so much around it must be changed for a/c use.

I have little doubt that a P-intake Renesis with reduced-diameter P port 'timed' later to minimize overlap would be lighter (simpler intake), produce more usable power than a stock Renesis even in the lower rpm range (5k-7k rpm), and would be quieter/less offensive in sound than a 13B, but it won't be the 1st rotary I fly, because Dirty Harry was right.

Charlie
I like where your head is at.
 
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