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RV-7 engine/prop options

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frank.hinde(at)hp.com
Guest

Posted: Mon Apr 23, 2007 6:30 am Post subject: RV-7 engine/prop options

I dug into this one with some vigour before eventually settling in on a

2.25" prop extension with a new Hartzell C/S BA prop. (The actual length

should be 2 and 5/8ths but 2.25 is what Sam Tillman had in stock).



Bottom line its not an issue, all of the normal manouvers can be

performed within 3G's and try as I might My max recorded g so far has

been +5 and -1G's...Its just not pleasant beyond 5G and the RV is just

not a hard core aerobatic machine, the Gyroscopic loads (so I'm told)

are nothing like those in say a Pitts...This airplane is going through

the motions but a Pitts is trying to rip the prop off in comparison.



Sam Tillman (Sabre prop extensions) will tell you some hairaising

stories about what his extensions have been put thru but there has never

been a failure of the extension.



If you go with an Airflow Performance FI system and a FF sump (As I did)

it's a very tight fit...The Bendix will fit much easier.



Yes I used Mattituck, Mahlon Russel is one of a handful of folks who

know more about airplane engines than I ever will. Service has been

superb. (Mahlon also supports the prop extension on the RV)



Annecdotally I have never heard a bad word said about Mattituck,

Aerosport, Barratt..All highly reputable firms.



The cowl looks superb with the right paint job and Two of my buddies are

also building the Sam James Cowl. 



Frank 7a 



--

John Brunke

Joined: 10 Jan 2006
Posts: 43

Posted: Mon Apr 23, 2007 10:14 am Post subject: RV-7 engine/prop options

Charlie,



About a year ago I was talking to a women in Hartzell's engineering 

department about the hub extension.

Sorry I don't recall her name.   Anyway Hartzell is worried about the stress 

levels on the extended hub

during any acro.  You could argue that the hub should at least be good up to 

3.8 G's normal catagory, but

do you want to be the test pilot that finds out?



Like you I am leaning towards the James cowl so the extension is definitely 

needed.

I talked to the folks at Aerocomposite props.   Not only will their 

extensions stand up to the g-loading,

they are very familiar with Sam James Cowl and what is required.   They also 

don't have any RPM type

restrictions on their props like Hartzell does.



I was just talking to a -7 owner at Sun and fun who has the James cowl and 

an MT prop.  MT's are an

excellent prop, but he said it was quite a hassle getting the correct length 

hub from them.  Now that they've

done his airplane, they might be more knowledgable about the whole thing.



Either composite prop is going to be a lot more than the Hartzell, but piece 

of mind sometimes costs a little extra.  I only plan on

building one RV7.   If I can do it right the first time, it will be cheaper 

in the long run.



John Brunke

RV7 tip-up in progress.

---

frank.hinde(at)hp.com
Guest

Posted: Mon Apr 23, 2007 10:59 am Post subject: RV-7 engine/prop options

That argument may have some validity as far as the extended (M) hub prop

is concerned. But The Compact (C) hub prop does not care....The

extension and the big crank bearing and the crank itself are the

components that will see the extra force or torque of acro with a prop

extension....Not the prop.



Hartzell is concerned about the EXTENDED HUB PROP....this is not the

same as the compact hub prop plus extension.



This set up has been done numerous times and there have been no failures

of the Sabre prop extension. Mahlon russel told me he would "do it in a

heartbeat"...Really it's a non issue I think. When you consider just how

much G force (and Gyroscopic force) the professional acro boys and girls

put on a Lycoming crank (you ever see Kirbly Chambliss do an English

Bunt flip/ tumble thingy?) then you know they don't break...At least not

for that reason.



Sure I had the same conversation with an engineer at Hartzell...he even

said do not use a prop extension period..Why?...Well because Hartzell

cannot guarantee the extension will not fall apart etc....In other words

it was hartz's official don't sue me line....He also pointed out the RV

was by nature a pretty gentle acro plane...I.e in his personal opinion

"don't worry about it".



Now of course one could get into the whole prop debate too but for me at

least the hartz was the fastest prop that Van's tested and its by far

the cheapest too.



As they say YMMV...



Frank



--

John Brunke

Joined: 10 Jan 2006
Posts: 43

Posted: Mon Apr 23, 2007 2:16 pm Post subject: RV-7 engine/prop options

Frank is correct.  The engineer at Hartzell was talking about the M hub 

prop.   I did not know

about the Sabre extension.    Thanks Frank for adding more decisions to the 

decisions.  : )

Just when you think you've got things figured out........................

John Brunke



---

gmcjetpilot

Joined: 04 Nov 2006
Posts: 170

Posted: Tue Apr 24, 2007 1:25 am Post subject: RV-7 engine/prop options

Hartzells or the BA new ones do not have RPM limits. 

  

James Cowls come in short lengths, so extended hubs are not needed.

   

  MT props are way slower with their fat wood / fiberglass blades.

MT props are also more money, cost more than twice as much to 

overhaul and may take many many weeks and shipping 

to Germany or who knows to have work done. Hartzells can be 

locally overhauled, often in a few days. Also nicks and 

delaminations on a MT means removal from plane and disassembly.

A nick in a hartrzell can be filed out on the plane.

   

  As far as other "experimental props" you are taking more chance 

flying them than a extended hub hartzell doing 3.0 g aerobatics. Ask 

them if they have done flight test and vibration survey with the Lyc on 

a RV or with electronic ignition or high compression pistons. The new 

Hartzells have been tested and optimized for RV's as has  the 

Sensenich. Guess who makes the fastest props for RV's? (5-9 mph)

Hartzell and Sensenich and they are both the best value and the least 

expensive of constant speed and fixed props respectively. Plus they 

are backed up by a large company.

   

  George

   

   

   

   

   

  >From: "J. Brunke" <jdoody727(at)comcast.net>

 	  Quote: 	
		  Subject: Re: RV-7 engine/prop options



Charlie,



About a year ago I was talking to a women in Hartzell's engineering 

department about the hub extension.



  >Like you I am leaning towards the James cowl so the extension is 
	


 	  Quote: 	
		  definitely needed.



  >They also don't have any RPM typerestrictions on their props like Hartzell 
	


   >does.

 	  Quote: 	
		  

MT's are an excellent prop, but he said it was quite a hassle getting the 

  >correct length hub from them.  
	




           Ahhh...imagining that irresistible "new car" smell?

 Check out [url=http://us.rd.yahoo.com/evt=48245/*http://autos.yahoo.com/new_cars.html;_ylc=X3oDMTE1YW1jcXJ2BF9TAzk3MTA3MDc2BHNlYwNtYWlsdGFncwRzbGsDbmV3LWNhcnM-]new cars at Yahoo! Autos.[/url]  [quote][b]

gblakey(at)vic.australis.
Guest

Posted: Tue Apr 24, 2007 2:17 am Post subject: RV-7 engine/prop options

Interesting  George....though clearly WhirlWind may be worth a look!    Faster  and significantly lighter than the Hartzell, specifically developed for  RV's and with no RPM limitations.  Take a look at the review carried out in  the RVaitor in 2005.

  

 Cheers,

  

 Greg Blakey (FADEC  IOF360-M1B and WhirlWind 200RV)

 [quote]   ---

frank.hinde(at)hp.com
Guest

Posted: Tue Apr 24, 2007 5:50 am Post subject: RV-7 engine/prop options

Correct george I had forgotten that James now make short  cowls.

  

 However, with an Airflow performace throttle body there is  no way it would all fit on a forward facing sump..I am sceptical if a bendix  would fit either but I don't know for sure...This is assuming ou want the James  alternate air source...I could not get mine to fit (FF sump, AFP with an  extended cowl).

  

 Frank



   From: owner-rv7-list-server(at)matronics.com  [mailto:owner-rv7-list-server(at)matronics.com] On Behalf Of  gmcjetpilot(at)yahoo.com

Sent: Tuesday, April 24, 2007 2:24  AM

To: rv7-list(at)matronics.com

Subject: Re: RV-7  engine/prop options

 

 Hartzells or the BA new ones do not have RPM limits. 

 

James Cowls come in short lengths, so extended hubs are not  needed.

  

 MT props are way slower with their fat wood / fiberglass blades.

MT  props are also more money, cost more than twice as much to 

overhaul and may  take many many weeks and shipping 

to Germany or who knows to have work done.  Hartzells can be 

locally overhauled, often in a few days. Also nicks and  

delaminations on a MT means removal from plane and disassembly.

A nick in  a hartrzell can be filed out on the plane.

  

 As far as other "experimental props" you are taking more chance 

flying  them than a extended hub hartzell doing 3.0 g aerobatics. Ask 

them if they  have done flight test and vibration survey with the Lyc on 

a RV or with  electronic ignition or high compression pistons. The new 

Hartzells have been  tested and optimized for RV's as has the 

Sensenich. Guess who makes the  fastest props for RV's? (5-9 mph)

Hartzell and Sensenich and they are both  the best value and the least 

expensive of constant speed and fixed props  respectively. Plus they 

are backed up by a large company.

  

 George

  

  

  

  

  

 >From: "J. Brunke" <jdoody727(at)comcast.net>

 	  Quote: 	
		  Subject:  Re: RV-7 engine/prop  options



Charlie,



About a year ago I was talking to  a women in Hartzell's engineering 

department about the hub  extension.



 >Like you I am leaning towards the James cowl so the extension is  
	


 	  Quote: 	
		  definitely needed.



 >They also don't have any RPM typerestrictions on their props like  Hartzell 
	


 >does.

 	  Quote: 	
		  

MT's are an excellent prop, but he said it was  quite a hassle getting the 

 >correct length hub from them.  
	


 

  Ahhh...imagining that irresistible "new car" smell?

Check out [url=http://us.rd.yahoo.com/evt=48245/*http://autos.yahoo.com/new_cars.html;_ylc=X3oDMTE1YW1jcXJ2BF9TAzk3MTA3MDc2BHNlYwNtYWlsdGFncwRzbGsDbmV3LWNhcnM-]new  cars at Yahoo! Autos.[/url] [quote]



href="http://www.matronics.com/Navigator?RV7-List">http://www.matronics.com/Navigator?RV7-List

href="http://forums.matronics.com">http://forums.matronics.com



[b]

John Brunke

Joined: 10 Jan 2006
Posts: 43

Posted: Tue Apr 24, 2007 5:51 am Post subject: RV-7 engine/prop options

George,

  

 I was just looking at Van's website store.  If  you click on the Hartzell props, just below the list of props is a link to click  on that

 takes you to Hartzell.   They proceed to  list RPM restrictions there for the various models.     Do  you have a different prop

 than what is on this list?    

  

 I agree that the maintenance issue is a good  selling point and the price.   However I know for a fact that the  AeroComposite props do not

 carry any RPM limits.   In fact they have  tested them at over 3000 RPM's.   Being composite they do not have the  resonance

 problem that can occur with a metal prop at the mid  RPM's listed on Hartzell's site.  

  

 By the way I am getting good info from this  thread.  Please put some differing opinions in here.  That's what  makes this list

 worth reading.

  

 John Brunke

  

 [quote]   ---

frank.hinde(at)hp.com
Guest

Posted: Tue Apr 24, 2007 5:55 am Post subject: RV-7 engine/prop options

Significantly faster????...First I've heard of that..Are  you sure??

  

 Frank



   From: owner-rv7-list-server(at)matronics.com  [mailto:owner-rv7-list-server(at)matronics.com] On Behalf Of Greg  Blakey

Sent: Tuesday, April 24, 2007 3:20 AM

To:  rv7-list(at)matronics.com

Subject: Re: Re: RV-7 engine/prop  options

 

 Interesting  George....though clearly WhirlWind may be worth a look!    Faster  and significantly lighter than the Hartzell, specifically developed for  RV's and with no RPM limitations.  Take a look at the review carried out in  the RVaitor in 2005.

  

 Cheers,

  

 Greg Blakey (FADEC  IOF360-M1B and WhirlWind 200RV)

 [quote]    

[b]

ktlkrn(at)cox.net
Guest

Posted: Thu Apr 26, 2007 8:10 am Post subject: RV-7 engine/prop options

I haven't read all of the posts on this but I  wanted to comment on this thread. This is my experience with the good and bad  and 100% honest. I have a RV7 with ECI IO 360, dual Pmag set up with Precision  FI system. Nothing hopped up or fancy on the engine. My prop  is the  Whirlwind 200RV. I purchased mine from Whirlwind before they were sold to Titan  aircraft.

  

 As has been noted, the 200 RV was designed for RV  airframe. Specifically I cannot say what type of testing or research was done,  but from the performance it clearly works.

  

 On initial flights I was getting significant  surging with the prop. If the throttle was applied slowly there was no issues.  If applied quickly there was a lag then the prop would grab. The best analogy I  can give you, it was like driving a manual transmission car and after getting  rolling you just suddenly let out the last little bit of clutch to get a little  jolt.

  

 At 55 hours and on my last flight before breaking  down for paint, a seal went out in the hub. I initially got a little oil on the  windshield. After landing and shutting down I noticed oil pouring out of the  front of the hub. I took the prop off and boxed it and sent to the new WW. Greg  called me and let me know a seal was apparently installed improperly during the  hub manufacture. He said the seal was most likely causing the surging. No  coverups but an honest evaluation of the problem and the fix.

  

 The other known problem with the WW has been with  the spinner backplate brackets. I  to has this problem but this to was  taken care of with minimal discomfort and down time.

  

 Now the performance. Another 7 is based at my  airport with the same engine. His weighs probably 50lbs less. He has the  Hartzell BA prop. At the same power settings my plane will run away from  his. 

  

 I had the prop dynamically balanced a couple of  weeks ago and the balancer got it to 0.00. He said he has never got one perfect.  He also  noted the blades track better than  anything he has  seen.

  

 Another performance story. Robbie Attaway,  (Attawayair.com) has a 6 with considerably worked ECI IO 360 with the ECI  cold air sump and their FI system. He initially had a Hartzel BA on it. He  wanted more speed and spent ton of money on an  Aerocomposites prop. He did  not get the performance he thought he would couple with a couple of structural  issues so he returned it and ordered another Hartzel. The Hartzel lead time was  4-5 months. 

  

 One of my neighbors has a WW 200RV for his plane as  was not going to be using for a while. Robbie put it on his plane and using his  words, "the airplane came to life." He said the plane is considerably faster and  smoother. After only a few hours, he ordered a WW 200RV. Within a few weeks he  had the prop and couldn't be happier.

  

 Many will continue to go with the Hartzel because  it seems like "the standard." If you want a superior prop in performance  and smoothness consider the WW. The company is great to work with. There  availability and service is excellent. This is a big company that isn't going  anywhere. Give them a look.

  

 Robbie will be happy to talk to you about his  experiences. He can be contacted through his web site, www.attawayair.com

  

 Darwin N.Barrie

 Chandler AZ

 RV7 N717EE

  

   [quote][b]

John Brunke

Joined: 10 Jan 2006
Posts: 43

Posted: Thu Apr 26, 2007 9:06 am Post subject: RV-7 engine/prop options

Darwin,

  

 Thanks for the input.  Do you know of anyone  who has put an extension on the Whirlwind for use with a James  Cowling?    

  

 John Brunke

  

 [quote]   ---

ktlkrn(at)cox.net
Guest

Posted: Fri Apr 27, 2007 6:27 am Post subject: RV-7 engine/prop options

Not that I know of but my neighbor is going to use  the WW and the SJ cowl. Give Greg call at WW and talk to him. They are great  people to work with.

  

 Darwin N. Barrie

 Chandler AZ

 RV7 N717EE

   [quote][b]

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