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Date: Sun, 28 Mar 2010 22:02:08 -0500
From: Charlie England <ceengland@bellsouth.net>
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To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: More Renesis Flight Data
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Sounds like your -6 was right on the money to match Van's numbers; 75% 
power on a 160 lyc is between 8.7 & 9.0 gal per hour, depending on how 
much avgas weighs at the moment (some say 6lb/gal, some say 6.2).

Sounds like you're doing as well as Tracy on efficiency; that's very 
encouraging.  Please keep us updated on your performance/efficiency numbers.

Thanks,

Charlie

On 3/28/2010 9:30 PM, Mike Wills wrote:
> Charlie,
>
> I flew an RV-6A with 160HP Lyc (original builder bought the engine new 
> from Vans - it had 85 hours on it when my partner and I bought it) and 
> a FP Sensenich metal prop for about 200 hours. The airplane wasn't a 
> show winner but was well built and straight. All stock Vans (cowl, 
> pressure recovery pants, stock Hoerner wingtips). It weighed 1054 
> empty. At 8000 and 75% it was a 180MPH airplane. At the cruise 
> alt/speed it burned right at 8GPH.
>
> I still havent flown my RV-4 enough to really know what it will do. I 
> have flown with my buddy who was flying my old -6A and with us both at 
> full throttle, 8000' I had to back way off on power for him to keep 
> up. I have found that if I setup a cruise at the same 180 MPH that I 
> used to fly in the -6A my EFISM reports fuel flow of about 8.5GPH. 
> I've toyed a little with leaning and my narrow band O2 sensor also 
> goes off scale. But as I lean my EGTs split and the split widens the 
> leaner I go. Once I finally get all the bugs worked out and regain 
> confidence in the airplane I'll experiment further.
>
> Mike Wills
>
> --------------------------------------------------
> From: "Charlie England" <ceengland@bellsouth.net>
> Sent: Sunday, March 28, 2010 11:54 AM
> To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
> Subject: [FlyRotary] Re: More Renesis Flight Data
>
>> On 3/28/2010 11:34 AM, Dennis Haverlah wrote:
>>> Chris,
>>>
>>> Your static is very low compared to mine!  My static is in the range 
>>> of 5800 to 5850 rpm IIRC.  I'll confirm  static rpm soon.  Does the 
>>> engine run smoothly at max rpm?  I didn't know your engine was a 4 
>>> port Renesis - I thought it was an  earlier RX-7 unit.
>>>
>>> A question was asked about my exhaust system and Hp.
>>>
>>> I do slightly better than my neighbor's 180 hp. Lyc, powered RV-7A.  
>>> He and I will try to make some more comparisons this spring.  I 
>>> believe mine is in the area of ~190 Hp. but it is only a guess.  
>>> This is one reason I wanted to post performance numbers so we can 
>>> compare similar and different systems.
>>>
>>> My exhaust uses the Renesis exhaust manifold.  The exhaust is 
>>> pointed forward toward the prop.  To reverse the flow, I used a 4" 
>>> dia. stainless tube mounted horizontally and parallel to the prop.  
>>> The tube acts as a swirl tube - the flow enters parallel to the 
>>> inboard end and exits parallel to the outboard end of the swirl tube 
>>> and the exhaust is toward the rear of the aircraft.  The exhaust 
>>> than enters a Hushpower II _Resonator_ and than out and down to the 
>>> rear. The resonator is shorter than the normal Hushpower II 
>>> muffler.  All my exhaust system is inside the cowl.  I used some 
>>> stainless and some aluminum for heat shields. With 230 hours of 
>>> total run time I have not had any problems.
>>> See attached picture and the article in the current issue of Van's 
>>> Rvaitor.
>>>
>>> When I built the exhaust system "Swirl Mufflers" were the "in thing" 
>>> on the list.  Also, I had trouble finding 180 deg. stainless tubing 
>>> with a sharp enough bend radius to fit in the space available in the 
>>> cowl.  If I were building it now I'd use a 180 bend stainless tube 
>>> instead of the swirl tube.  Probably would make a little more noise 
>>> and Hp!
>>>
>>> Dennis Haverlah
>>
>> Hi Dennis,
>>
>> I pasted the numbers from Van's web site for the 7/7A and from your 
>> previous post below. Van's numbers are almost certainly for a 
>> constant speed prop, so your climb numbers would be in the ballpark 
>> for 180-200 hp. But the cruise numbers don't line up at all, so I'm 
>> trying to sort out the reasons for the discrepancies. Full throttle, 
>> fully leaned at 7500' with a Lyc 180 hp should produce a tad over 10 
>> gal/hr (maybe 10.5 on a bad day) & a tad under 200mph. Many -6's & 
>> 7's have shown this to be a repeatable number. If you're showing 195, 
>> you'd be in the ballpark for speed, but the fuel flow is way higher 
>> than I would expect; a 5% penalty is understandable but a ~20% 
>> penalty is surprising. Was that 7500' run at full throttle and leaned 
>> to best power or full rich?
>>
>> 8-8.8 gph at 7500' should yield a speed slightly under the 160hp 
>> 7500' (75%) speed of 192 mph. Again, repeatable among multiple RV-x's.
>>
>> If your neighbor's Lyc numbers are worse than yours, he's got 
>> something seriously wrong with either his plane or his operating 
>> technique (maybe afraid to lean the Lyc properly?).
>>
>> Tracy & I (a rather dirty Lyc 160hp RV-4) have done a couple of 
>> same-altitude/same-speed cross countries together, & he's been about 
>> 5% worse (a reasonable, acceptable compromise #) than me both times, 
>> with both of us flying his low/mid altitude economy flight profiles. 
>> No one else flying a rotary seems to come anywhere near his fuel 
>> efficiency numbers. I'm curious about whether the variations from 
>> Van's numbers are due to major cooling drag differences, or 
>> tuning/engine setup issues.
>>
>> Anyone have any thoughts?
>>
>> Charlie
>>
>> /Solo Weight 1400 lbs
>> Gross Weight 1800 lbs/ *160 hp* *180 hp* *200 hp*
>> */Empty weight and performance measured with Hartzell 2 Blade C/S prop/*
>> *Speed - Solo Weight*
>> Top Speed 202 mph 210 mph 217 mph
>> Cruise [75% @ 8000 ft] 192 mph 200 mph 207 mph
>> Cruise [55% @ 8000 ft] 173 mph 180 mph 187 mph
>> Stall Speed 51 mph 51 mph 51 mph
>> *Speed - Gross Weight*
>> Top Speed 201 mph 209 mph 216 mph
>> Cruise [75% @ 8000 ft] 191 mph 199 mph 206 mph
>> Cruise [55% @ 8000 ft] 172 mph 179 mph 186 mph
>> Stall Speed 58 mph 58 mph 58 mph
>>
>> *Climb/Ceiling - Gross Weight*
>> Rate of Climb 1,400 fpm 1,650 fpm 1,900 fpm
>> Ceiling 18,500 ft 20,500 ft 22,500 ft
>>
>>
>>
>> Numbers from previous post:
>> Field elevation  900'
>> Climbed @  110 kts. indicated air speed  - Full throttle climb to 7500"
>> OAT 70 deg. at takeoff
>> Initial climb rate was 1800 - 1900 fpm
>> ( I get ~ 2400 fpm with only 21 gallons in the tanks)
>>
>> @ 4500" the climb rate was ~ 1400 fpm
>> Water 188 F, Oil 200 F
>>
>> @ 6000' the climb rate was ~ 1250 fpm
>> Water 188 F, Oil 203 F , OAT 60 F
>>
>> @ 7500' climb rate was ~ 1000 fpm
>> Water 189 F, Oil 204 F
>>
>> I leveled off for about 5 minutes than went to full throttle again.
>>
>> _Full throttle for about 3 ot 4 minutes @ 7500' _
>> MP 23.3 in.
>> Fuel flow - 12.1 gph
>> TAS 193 mph  - EM-2 data
>> Engine: 6660 - 6680 rpm
>> Water 184 F, Oil 205 F  OAT 65 F
>>
>> When I fly at 7500' I _normally_ use 8 to  8.3 gph
>> TAS 157 mph
>> Water 160 F, Oil 180 F
>>
>>
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