R

Rdwrv4

Well Known Member
I bought a pretty much completed not flown yet RV4 IT is a 1980 kit and I am making a list of the mods that shoud be done and where to get the info to do it
1; seat mod info is on vans site ok
2; engine mount firewall reinforcement I want to do this but not sure of my options and where to get info on it. The tech support said there was something on the vans site but I could not find it
3; I will live with the shorter gear legs
4; tail surface skins too thin I know nothing about this one or where to get info
anything else ???
I would love to talk with an RV4 expert who could explain my options
I design avionics for a living
Robin 909 866 2099
 
Robin, the earlier -4s had the brake master cylinders mounted upside down due to the geometry in the forward tunnel area. Springs were pointed down instead of up, which made bleeding difficult. I remember having to disassemble the cylinders and turn them right side up temporarily for bleeding. A royal pain. Later we modified the brake pedals and mounted them correctly. Not sure if there was ever a mod kit, but I believe the later kits had them mounted correctly. We just came up with our own mod. Yours may be already modified. :)
 
There's absolutely nothing wrong with the original .016" skin on the elevators and rudder if done correctly.
My -6 has been flying for over 19 years with not a single crack.
Just make sure that the trailing edge radius is properly done.
 
Opinions

Hi,

On point 2. there are two kinds of mount reinforcement.

1. A gusset welded under the lower cross tube where the gear leg tube meets, several a/c in the UK have this mod.

2. An aluminium gusset inside the fuselage lower weldment and angle on the rear of the firewall....... there are photos of this on my blog. The gussets are frum an rv8 and can be ordered from Vans.

Shorter gear legs are not a problem.....just less clearance for the prop. The old style wheel pants will cost you a few knots over the new pressure recovery type. Personally I dont like the old style alum gear leg fairings so made some new ones using my RV 9 ones as a plug. Again, replacements are available from Vans or Sam James.

The standard tail surface skins are fine as said above if properly made, but the can crack at the back edge, in fact I saw a 6 with cracks on the rudder today. I would go with the originals and just keep an eye on them to check for cracks in the trailing edge.

Hope this helps.
 
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