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Buying RV-4 questions

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Chadmeyer24

Active Member
Hey guys/gals
I'm looking to buy a rv4 that was finished in 2003 but was a kit from the 90's I believe.
I know of the weldment issues on the old ones and can't seem to find a good set of pictures on here as to how to identify which it has or where exactly to look for issues with these (besides the fact that they are on the aft side in the corners of the firewal). It does have the long gear legs if that makes any difference.
Also, the airplane has an io360 and C/S hartzel and the thinner elevator skins and I've read horror stories about that combo? Where exactly do the elevators start cracking? Pictures would be great! The airplane is still unpainted so is easy to inspect.
Airframe/engine TT 500hrs

Any additional words of wisdom would be appreciated greatly!
Pictures speak 1000 words :)
Thanks guys
 
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The "horror stories" of the .016 skins on tail surfaces and higher HP engines is a myth. Many of us are flying 180HP engines with these skins and no cracks.
The cracking issue is a result of improper build technique. Simple as that. Lots of threads on this issue if you want search.
It is hard to explain how to inspect for this but I will try. First take a straight edge down the rib/stiffener lines. The skin should lay flat all the way from the spar to the start, or nearly, of the trailing edge bend. Second, examine the trailing edge carefully where the stiffeners end. You may see the end of the stiffener telegraph itself through the skin slightly. This is normal and not a bad thing. This was caused by squishing the trailing edge. You had to squish it almost flat to get a proper trailing edge bend. Third, examine how the skin lays on the spar. It should lay flat and not be bowed or humped.
These are sublet things to check to insure the skin was not loaded when riveted. That is what causes the cracks, with any engine size.
 
Firewall wrinkles

My question is:

If there are wrinkles in the firewall, but new, modern, properly installed weldments, should those wrinkles be a deal breaker?
 
Saville said:
My question is:

If there are wrinkles in the firewall, but new, modern, properly installed weldments, should those wrinkles be a deal breaker?
Click to expand...

My personal answer would be it makes me wonder why the firewall wasn't removed and replaced if there was damage, structural or cosmetic, while replacing the weldments? It makes installing the new weldments 1,000 times easier....especially if doing all (4) weldments, (2) lower and (2) upper since construction methods of the factory weldments changed on both upper and lower weldments by Vans.

I guess it depends on the amount of wrinkles (if you can live with them), and if there are other issues to investigate.
 
Chadmeyer24 said:
Hey guys/gals
I'm looking to buy a rv4 that was finished in 2003 but was a kit from the 90's I believe.
I know of the weldment issues on the old ones and can't seem to find a good set of pictures on here as to how to identify which it has or where exactly to look for issues with these (besides the fact that they are on the aft side in the corners of the firewal). It does have the long gear legs if that makes any difference.
Also, the airplane has an io360 and C/S hartzel and the thinner elevator skins and I've read horror stories about that combo? Where exactly do the elevators start cracking? Pictures would be great! The airplane is still unpainted so is easy to inspect.
Airframe/engine TT 500hrs

Any additional words of wisdom would be appreciated greatly!
Pictures speak 1000 words :)
Thanks guys
Click to expand...

My -4, of the same vintage, has the same skin/engine combo. In my opinion, if the aircraft has 500 hrs with no cracks, it is not likely to crack in the future. I developed a number of cracks in my rudder early in the life of my plane. I stop drilled them and flew the plane for several more years. I then built an 0.020 skin rudder and keep the 0.016 rudder as a "spare".

Similarly, the elevator developed one small crack. I stop-drilled it 10 years ago and have not found any new ones. I have over 700 hrs on my -4. If I were building a new -4, I would use 0.020 skins for both the rudder and elevators, but only because the thicker skin is much more damage tolerant. I agree that it was likely builder error that contributed to the cracking, but it is easy to build that part wrong, especially, as it is done early on the learning curve.

Good luck,
 
Master Designs said:
I guess it depends on the amount of wrinkles (if you can live with them), and if there are other issues to investigate.
Click to expand...

*LIVING* with the wrinkles is my very question. If the weldments are of the new type and well installed, are the firewall wrinkles a health risk?
 
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Get some help...

Chadmeyer24 said:
Hey guys/gals
I'm looking to buy a rv4 that was finished in 2003 but was a kit from the 90's I believe.
I know of the weldment issues on the old ones and can't seem to find a good set of pictures on here as to how to identify which it has or where exactly to look for issues with these (besides the fact that they are on the aft side in the corners of the firewal). It does have the long gear legs if that makes any difference.
Also, the airplane has an io360 and C/S hartzel and the thinner elevator skins and I've read horror stories about that combo? Where exactly do the elevators start cracking? Pictures would be great! The airplane is still unpainted so is easy to inspect.
Airframe/engine TT 500hrs

Any additional words of wisdom would be appreciated greatly!
Pictures speak 1000 words :)
Thanks guys
Click to expand...

Chad,
If you're not an A&P nor have built an RV, especially a 4 I would get someone to look with you. The items you discuss should at least be inspected by someone experienced. The RV white pages on this site are a great resource to find a local RV4 builder owner nearby.
I built my RV4 back before the internet, this site's existence or the amazing resources available now. I have inspected over 200 RV's and always find something. I still have my IA friend "RR" look mine over after I have and he always finds something! Thus my RV4 pre-purchase checklist has over 200 items!

If nobody up there will help. email me offline and I can recommend somebody. Realize a good pre-purchase normally will cost $500 or more and is worth every penny considering your potential $$$ investment.

V/R
Smokey
[email protected]
 
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Thanks for all the inputs guys.
I am an A&P so I'm fairly confident doing an inspection I was just curious for things to look for on the 4 that are problem areas.
 
I'm sure you figured it out buy now, but I found a picture so I thought I would post it. Split type on the left, newer style on the right. Another feature you can use to identify the newer style is the flange added to the bottom of the front triangular piece.
410702879.jpg
 
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