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What to look for in an RV-4?

S

Seppe

Member
Hello all I've been a pilot flying a Cherokee since 2006. I have recently started flying an RV4 with about 40 hrs so far. I am loving it, this little plane is so docile and just a blast to fly. I am now leaning towards selling my Cherokee and upgrading to an RV4. I want to start looking very soon into this.

Now for all you RV4 owners/builders, can you give me some knowledge as to what I should be looking for in an already built RV4.

For example;

What flaws should I really be looking for in the build?

What years come with the longer gear, and is this better?

What year frames are actually better?

Is there supposed to be a G meter that is un-resettable to monitor the G stress levels on the RV?

I'm really wanting information on what to look at on the airframe. I know the engine and avionics are a whole separate case as far as value goes.

Any knowledgeable information that I can get would be so helpful. I appreciate any replies and look forward in talking with all of you.

Thank you
 
RV-4 info

Welcome to the fun.

Seppe said:
What flaws should I really be looking for in the build?
Not so much as flaws but overall build quality. The only thing they really changed for structural reasons was the firewall gussets. You can search the forums for more info on those.

What years come with the longer gear, and is this better?
You'll find all sorts of year RV-4's with all sorts of gear arrangements. Just because it was finished in 2010 doesn't mean it wasn't purchased in 1990. The long gear gives you a little more prop clearance for wheel landings, lands just a touch slower in 3pt but it also is more springy and has more of a chance to shake when taxiing.

What year frames are actually better?
No difference really. Long gear and short cowling are the main visual differences.

Is there supposed to be a G meter that is un-resettable to monitor the G stress levels on the RV?
No, the -4 if built correctly will handle 6G all day. Most guys test to that level and not past.

I'm really wanting information on what to look at on the airframe. I know the engine and avionics are a whole separate case as far as value goes.
Just look for a well built -4. Don't be scared by rudder cracks. Most metal prop -4's will have them. I would check the firewall at the lower engine mounts. Small cracks are often found there and not a problem but one that is bent there can be a problem. This relates back to the new gussets and hard landings.

They are great airplanes. There is a guy here on the forums named Smokey that specializes in matching -4s with new owners. Contact him for more in-depth knowledge.
Click to expand...
 
Thank you Sid

I appreciate any help I can get with this. I will reach out to Smokey and get as much information from him as possible.
 
Seppe said:
What causes the cracks on the rudder from a metal prop on the -4????
Click to expand...

Poor construction of the trailing edge.
The 4's suffer a bit more as their was less known about what was causing it than later down the line when the 6's, with basically the same .016 skinned surfaces, where being built. We knew to take care with the how they where formed and to tie the stiffners together with a dab of sealant.
There was a theory that vibration was causing the cracks. That theory doesn't really hold water anymore. Too many of us running 180HP plus motors with metal props and .016 skins with no cracks and hundreds of hours on them.
 
Seppe said:
What causes the cracks on the rudder from a metal prop on the -4????
Click to expand...

The rudder skin cracks are caused from the trailing edge not being formed properly. My -6 has been flying for 20 years with .016" skins, no internal sealant, and no cracks.

One major thing to look for is cracks in the lower engine mount weldments. These are the weldments aft of the firewall where the lower longerons meet the firewall. These can be cracked from harsh landing loads.
 
There you Go!!

Seppe said:
I appreciate any help I can get with this. I will reach out to Smokey and get as much information from him as possible.
Click to expand...

There's your answer. Talk to Smokey Ray. Buy some time with him. Seriously, you'll get the straight info. :)

Cheers,
 
RE: What to look for in an RV-4

As an RV-4 owner I'll offer my 2c on the following questions:

What years come with the longer gear, and is this better?

I'm unsure what year the long gear was offered.. but you can't rely on kit or build year to determine short/long gear since some have been converted. I would've preferred the long gear for more ground clearance.. but as you'll find in your search there is a limited inventory of RV-4s for sale. The short gear works great on my girl even with a 2 blade prop. I'd recommend you focus on build quality, engine specs, prop choice in that order.. instruments, interior, paint, etc can be modified (with appropriate $ of course) if you like.

The short gear RV-4 doesn't like to 3 point in my experience, I use wheel landings (and now prefer them on all surfaces.) I'm unsure if the long gear is enough to stall in a 3 point attitude.. perhaps a long gear owner can respond to that.

2. What year frames are actually better?

No particular year.. it's more about the craftsmanship. My early 80s kit was completed in 2010.

One issue to look for is "sloshed tanks." This is a sealant used in many of the early builds and can come loose and restrict/clog fuel flow. It's recommended that the slosh be removed or the tanks replaced.
 
Last edited:
Looking for a 4

You are only a couple of minutes from a ton of information, Corona, Chino and Cable airports have lots of RV's. Spend some time on the weekend and just drive over and talk to the builders. I'm sure they will be very glad to help educate you on the 4. Smokey is a long way away from you, he is a ton of information but there is a wealth of information and skill in your back yard. I'm sure when you find one your interested in you can find someone to help you with a pre-buy right where you are. Where do you fly the 4 out of?. I finished mine and first flew it out of Cable, there are a lot more there now.

RT
 
Party Line...

Seppe said:
I appreciate any help I can get with this. I will reach out to Smokey and get as much information from him as possible.
Click to expand...

"Talking is free, but if I have to get out my toolbox..."

My Dad, circa way back when :)

Smokey
863-397-1657
 
What to look for in an RV4

Hi.

This may be a little long winded, but I'd like to address a couple of your questions...but, I must admit that despite having owned 3 RV's, I've never built one, and RV4 builders are best qualified to tell you what to look for in construction flaws..

1) I agree that in so far as the year is concerned, it doesn't matter. It's the quality of workmanship that counts, since all RV4 kits are basically the same and none of them are "pre drilled quick builds". I presently own a 1990 kit, which took 15 years to finish. I don't think the 2013 RV4 kit is any different than the first models, except for the long gear option.

2) Long gear vs short gear.... This is an area that in my opinion, "the long gear" is a major improvement in the RV4 series. My first RV4 had the stock short legs, a wood prop on a basic carburated 0320. I flew it for 700 blissful hours. I then bought an "award winning", angle-valve 200hp Christan Eagle, learned some aerobatics, and sold it after 503 terrifying landings, which I could never get used to on my narrow home air strip, as it "had" to be landed "blind", in a three-point configuration. During this time, I regretted having sold my RV4. I then bought a V tail Bonanza, which consumed way too much gas and never suited my purpose, as most all of my flying was solo or at most, with one passenger. I finally went back to the RV and bought a very nice 6, with a constant speed prop on a fuel injected 0360. The 6 was fun, but it didn't give me the JOY of flying like the 4 did, so I sold it.

I now own a beautiful "high priced" 4 which I bought from a friend of mine. I was familiar with this airplane as it "smoked" my 6 in climbout and speed. It had 9:1 ported LyCon pistons, 227 hp of "cold air" induction on a IO360, CS 74" Hartzell Prop... with short legs. On my first landing with a passenger, I sustained a "minor" prop strike, grazing one blade and bending the other a quarter inch. Although this was considered a "minor strike", it resulted in me having to remove the engine and having it inspected as a " sudden stop prop strike" which is "major". I found out, there's no such thing "minor prop strike".... The incident cost me $6,800 for the basic inspection and $4,500 to repair the prop (with a new hub). In addition, I learned that the engine had some corrossion on the cam shaft lobes and the chrome cylinders and 9:1 pistons had to be replaced on account of some microscopic exhaust cracks. Long story short, and $23,500 later, I now have a new rebuilt engine and prop. Needless to say, I decided to spend the extra $1500 to convert the plane over to a "long gear", which required buying the new dynofocal motormount for the long legs (you can't just add the long gear to a standard dynofocal short gear engine mount).

So, in my case, there's no question as to what gear to go with. Had I three extra inches of long leg clearance, I never would have sustained the prop strike. Some contend that the long gear "bend" (or spread) on bounce more than the short gear, but I don't believe that's the problem. My strike was caused by me "nosing over" the prop too far, not by a hard bounce. If you do buy a "short leg" 4, make sure your prop has ample clearance and that the prop not be more than 70 inches (I think 68 is recommended by Vans).
 
SportAvServ said:
You are only a couple of minutes from a ton of information, Corona, Chino and Cable airports have lots of RV's. Spend some time on the weekend and just drive over and talk to the builders. I'm sure they will be very glad to help educate you on the 4. Smokey is a long way away from you, he is a ton of information but there is a wealth of information and skill in your back yard. I'm sure when you find one your interested in you can find someone to help you with a pre-buy right where you are. Where do you fly the 4 out of?. I finished mine and first flew it out of Cable, there are a lot more there now.

RT
Click to expand...
RT Thanks for the local information. Do you possibly have any names I can ask for when looking for these builders in Chino. I know Chino has many builders over there. I am flying the -4 out of Redlands and my home airport is Corona.
 
smokyray said:
"Talking is free, but if I have to get out my toolbox..."

My Dad, circa way back when :)

Smokey
863-397-1657
Click to expand...
Smokey you left me a phone # so I may call you in the near future if you do not mind for some questions that may pop up. I have worked closely with AP's since I started flying so I am aware of certain things to look for in aircrafts/engines. I am just trying to gather as much info on the -4 prior to my shopping.

Thanks
 
lella said:
Hi.

This may be a little long winded, but I'd like to address a couple of your questions...but, I must admit that despite having owned 3 RV's, I've never built one, and RV4 builders are best qualified to tell you what to look for in construction flaws..

1) I agree that in so far as the year is concerned, it doesn't matter. It's the quality of workmanship that counts, since all RV4 kits are basically the same and none of them are "pre drilled quick builds". I presently own a 1990 kit, which took 15 years to finish. I don't think the 2013 RV4 kit is any different than the first models, except for the long gear option.

2) Long gear vs short gear.... This is an area that in my opinion, "the long gear" is a major improvement in the RV4 series. My first RV4 had the stock short legs, a wood prop on a basic carburated 0320. I flew it for 700 blissful hours. I then bought an "award winning", angle-valve 200hp Christan Eagle, learned some aerobatics, and sold it after 503 terrifying landings, which I could never get used to on my narrow home air strip, as it "had" to be landed "blind", in a three-point configuration. During this time, I regretted having sold my RV4. I then bought a V tail Bonanza, which consumed way too much gas and never suited my purpose, as most all of my flying was solo or at most, with one passenger. I finally went back to the RV and bought a very nice 6, with a constant speed prop on a fuel injected 0360. The 6 was fun, but it didn't give me the JOY of flying like the 4 did, so I sold it.

I now own a beautiful "high priced" 4 which I bought from a friend of mine. I was familiar with this airplane as it "smoked" my 6 in climbout and speed. It had 9:1 ported LyCon pistons, 227 hp of "cold air" induction on a IO360, CS 74" Hartzell Prop... with short legs. On my first landing with a passenger, I sustained a "minor" prop strike, grazing one blade and bending the other a quarter inch. Although this was considered a "minor strike", it resulted in me having to remove the engine and having it inspected as a " sudden stop prop strike" which is "major". I found out, there's no such thing "minor prop strike".... The incident cost me $6,800 for the basic inspection and $4,500 to repair the prop (with a new hub). In addition, I learned that the engine had some corrossion on the cam shaft lobes and the chrome cylinders and 9:1 pistons had to be replaced on account of some microscopic exhaust cracks. Long story short, and $23,500 later, I now have a new rebuilt engine and prop. Needless to say, I decided to spend the extra $1500 to convert the plane over to a "long gear", which required buying the new dynofocal motormount for the long legs (you can't just add the long gear to a standard dynofocal short gear engine mount).

So, in my case, there's no question as to what gear to go with. Had I three extra inches of long leg clearance, I never would have sustained the prop strike. Some contend that the long gear "bend" (or spread) on bounce more than the short gear, but I don't believe that's the problem. My strike was caused by me "nosing over" the prop too far, not by a hard bounce. If you do buy a "short leg" 4, make sure your prop has ample clearance and that the prop not be more than 70 inches (I think 68 is recommended by Vans).
Click to expand...
Hey Lella I appreciate your input. Sorry for the mishap in the prop strike. All in all now you know what you have under the cowling. As far as the $1,500 for the longer gear?? That cost includes the new engine mount and the actual gear?? Is there anything else that would need to be purchased. How much time is involved in the install? I am assuming the entire engine needs to be removed and all associated parts??
 
Cost for the longer gear

Thanks. On the positive side, I do know now what I have under the cowling.

Cost on the new dynofocal mount and legs are $1500 with shipping, from Vans. Then you need to have the new motor mount powder coated (another$300). Aside from that, you need to replace the brake lines to accomodate the longer legs (I put flexible ones on) and bleed the brakes (which was a real pain since I had to invert the pedal brake cylinders to get the air out).

And here comes the worst aspect in all of this...the wheel pants don't line up anymore with the angle of the new longer legs, so they have to be cut and modified to fit. Last, and not least, new leg fairings.

For me, not being a builder...this whole operation was difficult and I needed help. Fortunately for me, I have a few great RV guys out there willing to loan me a hand....

Total cost...about $2000 and many hours to remove and install the engine.
 
RV Contacts

Seppe
Here is a link to Cable's EAA chapter, just stop at one of their meetings and I'm sure you will find several builders. Might ask around for Fred Laforge, not sure if he is in the chapter but he had built a 4, Harmon Rocket and is a machinist. PM me if you need any more info.

http://www.eaa448.org/EAA448/Home.html
 
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