VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

  #11  
Old 06-06-2013, 07:45 PM
hohocc hohocc is offline
 
Join Date: Sep 2008
Location: Christchurch, New Zealand
Posts: 187
Default

A couple of suggestions you may like to look at.
Tailwheel: Vans have a standard and a lightweight tailwheel, the less
weight right at the back the better for what you are trying to do.
Stinger: Try this link: http://www.irondesign-airparts.com/index.html
I understand this chap can make a titanium stinger, for a further
weight saving way down the tail end. I've not been able to get an
answer as to if it is a direct replacement for the vans stinger
though.
Reply With Quote
  #12  
Old 06-07-2013, 01:48 PM
n82rb's Avatar
n82rb n82rb is offline
 
Join Date: Jan 2007
Location: fort myers fl
Posts: 949
Default

the CG problem is easy to solve, get out your credit card and buy a o360 and a constant speed hartzell.

bob burns
RV4 N82RB
Reply With Quote
  #13  
Old 06-07-2013, 03:38 PM
nauga nauga is offline
 
Join Date: Jan 2007
Location: AOTP
Posts: 192
Default

Quote:
Originally Posted by dealfair View Post
We were chatting and he told me he had a 4" prop extension machined out of 4130 steel. He said it weighs 50 pounds...
50# at the crank flange would my my CG forward about 2". That's a lot in the right direction.
Moving my 250# O-320 4" forward would move the CG forward about 1". That's not a lot for the effort it would take. I'm not so sure I'd hang 50# at the end of the crank though.

As it is, my CG is creeping aft as I rebuild my panel and cockpit and a bunch of other stuff. I'm adding a Landoll balancer...maybe, a lightweight tailwheel, and if I can convince my supplier management/finance focal, a Catto 3 blade to replace my wood prop. That and a good diet should get me where I need to be.
__________________
Nauga
2004 RV-4
Reply With Quote
  #14  
Old 06-08-2013, 02:53 AM
newrv-4 newrv-4 is offline
 
Join Date: May 2013
Location: Raleigh, NC
Posts: 20
Default Replacement gear

So now that I am modifying my engine mount I might as well change from the short gear to the long gear. I have read a lot of opinion about the two, but in the end I will let my friends fly it and I do not want a prop strike. So, the long gear it is. I have been trying to research the long gear but have come up short on information, such as the change in attachment angle at the engine mount.

While I was researching it I saw it mentioned that the max gross of the RV-4 is limited by the landing gear. While I have no intention of flying it over 1500lbs often, a little extra loading room would be great for cross countries. With a system similar to the safe air tanks I would be happy to turn that extra weight into fuel capacity. So my question is I does anyone know of where to get heavier duty RV-4 landing gear. The rocket gear is a little expensive. I saw some posts about RVs that are so equipped. The next question is that if I can not purchase it, What does the present long leg gear look like? Is it a tapered tube? Is it solid bend like the 8?

Last edited by newrv-4 : 06-08-2013 at 04:57 AM.
Reply With Quote
  #15  
Old 06-08-2013, 05:34 AM
fixnflyguy fixnflyguy is online now
 
Join Date: Jan 2006
Location: Winston-Salem, N.C.
Posts: 1,213
Default fly over to 8A7

Fly over to 8A7 which is 10 miles south of INT and I will show you my long leg -4 as well as my neighbors F1 Rocket for comparison. I also have my plan set you can look at to see the difference in the mounts. I built mine, and can tell you about anything you need to know about your challenges. Should be a short flight for you. Do you ever go to Gilliam McConell for BBQ ?
__________________
Bill E.
RV-4/N76WE
8A7 / Advance NC
Reply With Quote
  #16  
Old 06-08-2013, 06:32 AM
nauga nauga is offline
 
Join Date: Jan 2007
Location: AOTP
Posts: 192
Default

Quote:
Originally Posted by newrv-4 View Post
While I was researching it I saw it mentioned that the max gross of the RV-4 is limited by the landing gear.
Where did you find this and can you share the info? I looked into it a looooong time ago and found something very different from a source that should be pretty reliable.
__________________
Nauga
2004 RV-4
Reply With Quote
  #17  
Old 06-08-2013, 09:30 AM
newrv-4 newrv-4 is offline
 
Join Date: May 2013
Location: Raleigh, NC
Posts: 20
Default

I came across this information in the VAF forum archives. What have you read to the contrary?
Reply With Quote
  #18  
Old 06-08-2013, 10:14 AM
nauga nauga is offline
 
Join Date: Jan 2007
Location: AOTP
Posts: 192
Default

Quote:
Originally Posted by newrv-4 View Post
I came across this information in the VAF forum archives. What have you read to the contrary?
Years ago I had a brief conversation with Van about what set the weight limit. I don't know if opinions or data have changed since then so I suggest a call to the factory might be in order. Suffice it to say that after that conversation I was comfortable in raising my TOGW to 1600 lb. My aerobatic weight is unchanged.
__________________
Nauga
2004 RV-4
Reply With Quote
  #19  
Old 06-08-2013, 10:42 AM
newrv-4 newrv-4 is offline
 
Join Date: May 2013
Location: Raleigh, NC
Posts: 20
Default RV-4 Weight

I was unable to find the article mentioned in the VAF archives, but this is close http://rvbuildershotline.com/articles/grossweights.html While it does not say anything specific, it does make some obvious points.

" Several respondents stated that they had calculated G-load strength of their airplanes based on a ratio of standard category weight relative to aerobatic gross weight to arrive a higher gross weight.

For primary structural considerations, this is basically valid, but it does not take into consideration possibly safety issues related to higher stall speed, landing gear loads etc. Just because the wing won't break because of the higher gross weight doesn't mean that other bad things can't happen. "

Out of curiosity, what did Vans say to make you raise the gross to 1600?
Reply With Quote
  #20  
Old 06-08-2013, 09:05 PM
newrv-4 newrv-4 is offline
 
Join Date: May 2013
Location: Raleigh, NC
Posts: 20
Default RV-4 Weight

I still can not find a limiting factor for MGTOW in the RV-4. I did come across some additional information. Many Rv-4's in the US appear to use 1800 as the MGTOW. That is beyond what I would ever desire. As far as I can tell there were no additional airframe modifications.

"John Johanson told us about how he rebuilt his world spanning RV-4 to have a "wet wing" before his Antarctic adventure. The gross weight of his airplane at take off with 1000 liters of fuel (264 US gallons) was approximately 3000 pounds."

I do recall that Vans issued an airframe modification to add a larger aluminum bracket aft of the firewall to avoid buckling due to rough landings.

I have performed a little math on the Titanium landing gear and have not seen anything that would cause me to back off the project. From what I can determine I would only need to drill 4 holes to prepare a tube. Nothing too scary. Two where it meets the engine mount and two at the bottom to attach to an axel fitting that I will mill. Its either that or I just buy a set of long gear from vans. I wonder that they sell for and weigh. Changing the gear may not be worth the effort.
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 06:44 AM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.