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From: "Mike Wills" <rv-4mike@cox.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
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Subject: Re: [FlyRotary] Re: More Renesis Flight Data
Date: Sun, 28 Mar 2010 19:30:16 -0700
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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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