Looking for advice on purchasing a RV-4

Hello everyone,

My partner and I have just started looking for a flying RV4 to purchase. Can anyone offer some advice on what to look for, or if there?re any critical areas that warrant special attention during a pre-purchase inspection?

We?ve heard about tall verses standard length landing gear, what are some of the advantages and disadvantages of both?

Also, I?ve seen many pics with cracked gear leg fairings, how common is this?

Thanks for any info?

Tom

I can say that you shouldn't put a newly purchased RV-4 in an old hangar before a major wind storm.

If you do, you'll never get to fly it.

Don't ask how I know.

Best of luck and have fun.

Sounds like good advice Ohio, sorry to hear of your loss and thanks for throwing me a bone How many RV4?s did you check out before you found your first one and have you replaced it yet?

Jeez, 97 hits and not one response, tough crowd?

Tom,
I have a friend who purchased a pretty good -4 in FL. Unfortunately he was a trusting soul. Plane advertised a fresh annual. He got a seller recommendation to have an A&P to go over the logs and check the engine compression, engine condition, etc. It was advertised with a brand new prop. (any alarm there?)

He flew it back to TX from FL, and when he got home he had to rebuild the engine. Low compression, and all other sorts of problems.

If I were buying a plane, I would want MY A&P to do the inspections and look it over before I bought. I know it would cost a lot more, but it might be money well spent in the long run. Hard to believe any folks in the RV community would misrepresent anything, but it does happen.

Good luck, If you find a good one, it will be a pleasure to fly.

Wes Hays
RV-6A 740+ hrs
RV-7A Finishing Wings
Winters, TX

-4 issues to think about.

Tom, I put together a few thoughts aimed at someone planning to build a -4. I found these issues hard to find out about, so documented what I found. They might be interesting to you. If you want to take a look go here.

Good luck!

Wes Hays said:

Tom,
I have a friend who purchased a pretty good -4 in FL. Unfortunately he was a trusting soul. Plane advertised a fresh annual. He got a seller recommendation to have an A&P to go over the logs and check the engine compression, engine condition, etc. It was advertised with a brand new prop. (any alarm there?)

He flew it back to TX from FL, and when he got home he had to rebuild the engine. Low compression, and all other sorts of problems.

If I were buying a plane, I would want MY A&P to do the inspections and look it over before I bought. I know it would cost a lot more, but it might be money well spent in the long run. Hard to believe any folks in the RV community would misrepresent anything, but it does happen.

Good luck, If you find a good one, it will be a pleasure to fly.

Wes Hays
RV-6A 740+ hrs
RV-7A Finishing Wings
Winters, TX

Click to expand...

I agree, I wouldn?t buy a plane without a pre-purchase inspection. This?ll be my 4th plane and for the first time I?m going to take my own mechanic with me, rather than have a local shop do it.

Your friend?s big mistake was probably using a mechanic who was recommended by the seller. I find it hard to believe anyone in the GA community would misrepresent anything too, but I suppose it?s just human nature.

Steve Sampson said:

Tom, I put together a few thoughts aimed at someone planning to build a -4. I found these issues hard to find out about, so documented what I found. They might be interesting to you. If you want to take a look go here.

Good luck!

Click to expand...

Thanks so much Steve! This was exactly the kind of info I was hoping to find. It looks like I?ll be spending a lot of time reading your log the next few days.

R2 Aviation...

Tom, I have a side business consulting people on RV purchasing and sales, specifically the RV4. I built my RV4 between 89' and 96' and now have 1500 hours on it.

If I can be of service, let me know.

Rob Ray
[email protected]

Tom,

A few things cross my mind. Ensure the airplane has the beefed up engine mount attach points on the lower fuselage. Look for any wrinkled skin in that area and on the firewall.

Ask if the fuel tank pickup mod has been done.

Look for stress cracks around the last row of rivets in the elevators and rudder. With the .16 skins, this is common on the models with .16 skins.

Older models have the lower gear, with the split metal fairings, with later models using the tall gear, which gives a better touch down attitude for three point landings.....plus it just looks better on the ground. ...not a big issue either way.

If the airplane has a fixed pitch prop and a hollow crankshaft, ensure that the inner metal plug (about 10" back from the forward plug) is either not there, or has been pierced. Builders have taken delivery of their engines in the past, with it set up for a constant speed prop (rear plug installed) and the front plug has been forced out, causing loss of oil and off field landings. When I bought my 4, I asked, the builder didn't know and I asked for an inspection before delivery. The plug was found installed and had to be pierced to prevent any pressure build up.

Some people have used auto filters in their fuel system and periodically replace them. Most use a gascolator, which I think is better and less likely to clog up and stop fuel flow.

The O-360 powered 4, with either constant speed or metal fixed pitch prop is the way to go, but most 4s were built with O-320s.

Don't buy a 4 that weighs over 1,000#, unless you are willing to pay the price in payload. At 1,500 max gross wt., the 4 gets limited quickly.

Good luck,

Originally Posted by Dave Dollarhide
A few things cross my mind. Ensure the airplane has the beefed up engine mount attach points on the lower fuselage. Look for any wrinkled skin in that area and on the firewall.

If the beefed up mount easy to detect? Can you give a brief description on how I might determine if it?s been done?

Ask if the fuel tank pickup mod has been done.

If you have the time, I?d sure like to hear the details of this one.

Older models have the lower gear, with the split metal fairings, with later models using the tall gear, which gives a better touch down attitude for three point landings.....plus it just looks better on the ground. ...not a big issue either way.

Does the tall gear obscure the forward view? I?ve heard the tall gear allows for an approx 5 mph slower landing speed, have you found this to be true? And have you heard of any conversions from short to tall gear?

The O-360 powered 4, with either constant speed or metal fixed pitch prop is the way to go, but most 4s were built with O-320s.

Don't buy a 4 that weighs over 1,000#, unless you are willing to pay the price in payload. At 1,500 max gross wt., the 4 gets limited quickly.

We?re looking at one with the tall gear, 320 / FP 3-blade Cato prop and one with short gear, 360 / CS, but with an empty weight of 1025.

Would you expect to see much a difference in landing distances between these two?

Thanks for all the very useful info Dave!

Tom

My -4s weight and balance shoes it at 1061-LBs, I did the math the other day and found I fly it regularly at 1700 Lbs. with no adverse affects. Your mileage may vary, proceed at your own risk, with that said I think the -4 is one of the most under utilized/under rated planes in our segment.

Originally Posted by Dave Dollarhide
A few things cross my mind. Ensure the airplane has the beefed up engine mount attach points on the lower fuselage. Look for any wrinkled skin in that area and on the firewall.

If the beefed up mount easy to detect? Can you give a brief description on how I might determine if it?s been done?

REPLY: Check the lower mount reinforcements by each rudder pedal. The upgraded piece is probably made from .65, has a slight space under the lower flat piece, which also is bolted in with four bolts. You'll see some variance in building, but that's the basic description.

Ask if the fuel tank pickup mod has been done.

If you have the time, I?d sure like to hear the details of this one.

REPLY: The fuel pickup tube, inside the tank has rotated in a case or two, rising above the fuel level. The fix is to build a bracket from angle to prevent the rotation and safetly wire added to prevent the nut from backing off. Go to the Vans site, where you can download the bulletin.

Older models have the lower gear, with the split metal fairings, with later models using the tall gear, which gives a better touch down attitude for three point landings.....plus it just looks better on the ground. ...not a big issue either way.

Does the tall gear obscure the forward view? I?ve heard the tall gear allows for an approx 5 mph slower landing speed, have you found this to be true? And have you heard of any conversions from short to tall gear?

REPLY: I have the tall gear, but have flown one with the short gear. You can see over the nose in both cases during taxi. The tall gear will give better geometry for a three point landing, but I don't think there is really much difference in landing speeds. I'm not sure, but a conversion may require a change out of the entire engine mount. No big deal either way....short or long.

The O-360 powered 4, with either constant speed or metal fixed pitch prop is the way to go, but most 4s were built with O-320s.

Don't buy a 4 that weighs over 1,000#, unless you are willing to pay the price in payload. At 1,500 max gross wt., the 4 gets limited quickly.

We?re looking at one with the tall gear, 320 / FP 3-blade Cato prop and one with short gear, 360 / CS, but with an empty weight of 1025.

Would you expect to see much a difference in landing distances between these two?

REPLY: I don't think you will not notice much of a difference in landing distance, since the weight difference is probably slight and there will be more drag on the constant speed prop. You would notice a definate difference in landing technique, as the FP Cato will have you at idle most of the time on the approach...depending on weight and aft CG with a passenger, while you would have slightly more power on the CS prop. The biggest difference is the speed of deceleration with the throttle at idle, but it's just a matter of knowing the airplane. The CS will lose speed faster in the flare. All other things equal, I'd opt for the 360 CS and accept the extra 25#. Most RV4 drivers fly somewhat over the 1,500# limit anyway and the CS will give you a better cruise speed most likely.

Thanks for all the very useful info Dave!

Tom

maybe....

I'm going to respectfully disagree with a couple of Daves points:

1. An RV4 with O-360 CS AND don't buy one over 1,000 lbs.
That's a tall order. Most airplanes in this config will weigh over 1,000lbs.
Also, remember that you have 32 gallons of gas. You'll need to
consciously manage your power settings or that fuel supply will be short.

2. The fuel pickup SB: No chance !! Some dipsh*t forgot to tighten the nut and ran out of gas. Now, we are supposed to rip open the tanks on airplanes that haven't leaked in 15 years !!! I don't think so . Once/year I run each tank dry to verify that I can still get all the fuel out of it.

3. Firewall/gear re-enforcement. Clearly a good thing. But if an airplane shows no signs of damage why would you reject it ?

These are small nits mostly. But worth talking about. Good luck in your search.

John

Beefed up firewall corners

Tom a.k.a. as Low and Slow, You were asking about the beefed up engine mount. I suspect you were asking as much as anything about the beefed up fittings on the inside of the firewall. They are the part that has changed several times over the years.

I have edited a picture of one of the corners into the blog entry I refered you to before.

Hope it helps, Steve.

PS If you buy a -4 you will have to change to Low and Quick!

PPS If you want to see a picture of the current engine mount take a look in the 'Firewall Forward' section of my blog at the 2/12/06 entry. Double click it to enlarge the picture.

John_RV4 said:

3. Firewall/gear re-enforcement. Clearly a good thing. But if an airplane shows no signs of damage why would you reject it ?

John

Click to expand...

John, do you know the cost and the time required to install the Firewall/gear re-enforcement? Does Vans Aircraft consider it a mandatory upgrade and if not, do you have an any idea how many have been beefed up?

Good question...

I don't know the answer but I do plan to find out someday. I have an RV-4 that I bought that was finished in 1989. Obviously, before the updates were available.

Certainly it's not mandatory. In fact, I don't know if it is actually an update at all or if guys just buy the newer parts and replace them.

Maybe somebody who has updated their brackets could chime in ?

John

Steve Sampson said:

...PS If you buy a -4 you will have to change to Low and Quick!

Click to expand...

Good point, it's a name derived from my Champ flying days.

We're definitely buying a -4, it's just a matter of time, but with all that speed, I think I'll be flying slightly higher.

Tom
On the hunt for a -4

By Design...

Well said John.
I too have to respectfully disagree with Dave. I have flown just about every iteration of RV4 and my own now for 12 years/1500 hours. Since I now inspect and perform pre-buy inspections I have found some interesting statistics. 95% of the 25 RV4's I inspected last year were built with 0-320's (as that is what the builders manual recommends). 50% have been at least 10 years old with VFR panels and 72% had wood or composite FP props. Why? Because that is what Van designed it for. Speaking of Van's, the fuel tank AD mentioned above is a CYA in my humble opinion. Know where the engine quits feeding on the gauge and you're always better off.
There is nothing wrong with 180HP RV4's, they simply cost more($8K+ average) and historically weigh more. If you do build your RV4 with an 0-360, I would definitely install a wood or composite FP prop to keep the weight down and RV6 fuel tanks for XC utility. The long gear is standard now on all the RV4 kits as are the firewall gussets and taller canopy. You won't go much faster (5-10 knots average at top speed) and definitely won't go any further. With 100LL predicted to go over $5 a gallon, the 0-320 can run MoGas. Most 0-360's can't. Something to consider if you have a choice. Overall, you'll spend on average about $1,000 per knot speed increase over the 0-320.
Having looked at or closely inspected/flown over 100 RV4's, I have NEVER seen a painted 180HP RV4 under 1000 lbs. I'm sure they are out there, I just haven't seen one. That said, most of my customers don't specify engine size, they specify quality and bang for the buck value. Therefore, they mostly have ended up in 0-320 powered RV4's (with 1 exception) as they are the best value. Since my own 160+HP RV4 is a 1500 hour success story with a 0-320, I tend to agree with my customers...

Rob Ray
R2 Aviation LLC

There are people who will say 'build it light' or 'build it per plans' and describe that airplane X was designed by Van himself only in the same post suggest it is a good idea to add other features that add weight or say that an 'AD' issued by Van is a CYA move.


Seems pretty silly all of these arguments, why don't you put a 290 in the -4? It would be lighter still and get even better range.. with gas at 5 bucks a gallon and all.

People put 180's in 4's because they want to go a little faster and climb a lot faster than thier buddies and have bragging rights over thier buddies with the little engines (Then the guys with 160's buy Rockets and the cycle continues

It would be my suggestion to figure out your mission, and the plane you need will drop out naturally, or you'll discover that your needs conflict (e.g. 8gph and 250mph, IFR and simple etc).

Chuck

Apples and...

Good point Chuck although Rockets and RV4's are 2 completely different animals and not the point of the discussion. The Rocket is however a wonderful contradiction to all of the above, by design, as is the F16,(talk about bragging rights) but neither are RV4's.
Several folks might disagree with you on $5 gas being incidental though. AD's on experimental airplanes are by definition, FYI. Proper fuel management is the real issue.
As I stated, there is nothing wrong with 180HP RV4's, but they cost and weigh more. A great option for people who want a 180HP RV4 but can't get 100LL is the Superior XP-360A set up for MoGas. The 0-290 powered -4's and -3's fly nice, and are really low $$$ and lightweight. Fact is, I haven't flown an RV4 I didn't like!
Like you so eloquently put: Build or buy what fills your mission requirements. Keeping airplanes light applies to every aircraft out there, not just RV's.
This site is great as it helps people looking for or building an RV4 make educated decisons they couldn't make otherwise. Or as we say in the squadron, "an ounce of gouge is worth a thousand lbs of regulations".

My Dos Centavos...

Rob Ray
RV4, HR2
F16C on weekends...

We?re looking at two flying RV4?s, both with 0-360?s. Our first choice has Harmon Rocket II, 48 gallon fuel tanks, but the owners are waffling on the decision to sell. The other has the standard 32 gallon tanks.

If we have to settle for our second choice, are there any options for increasing the range?

ER tanks built by Hotel Whiskey Aviation and sold through SafeAir1.com. These will give you approximately 1 hour more range.

Thanks Mel, just what we were looking for.

Do you know anyone who's installed one? Do you have any idea time wise, how long it takes to install them and what major tasks are involved, wing removal, etc.?

Rule of thumb...

Whenever I think I might "need" something that I haven't verified in actual use, I DON'T do it. It's easy to get caught up in the internet chatter and conclude that you need all the latest and greatest "stuff". You don't.

Get your plane and fly the wings off of it. If you feel your flying is being restricted by fuel supply, then by all means, go for it. If not, you're not out any more $$ or downtime.

Now, what's this about 48 gal Rocket tanks .

John

My buddy has

Low n Slow said:

Thanks Mel, just what we were looking for.

Do you know anyone who's installed one? Do you have any idea time wise, how long it takes to install them and what major tasks are involved, wing removal, etc.?

Click to expand...

My buddy has them in his -8 and loves them. They're made of a long lightweight piece of aluminum tubing that slides into the lightening holes in the ribs, just in front of the spar. A small square tank is attached to the other end and has a filler door that is fueled at the wingtip. You just add a door on top of the wingtip to access it...really clever and very light. The other end is connected to the main tank in each wing and they just gravity flow into the mains. Gives around 5 hours total.

Regards,

Low n Slow, just a thought in case you have missed it. In view of the gross on the -4, it might just be worth adding up the weights involved to see you will not go over gross with larger tanks. Apologies if I am stating the obvious.

I need a pee before the tanks will run dry!

Cheers!

ER Tanks

Steve,

Here is a post of mine from several months back. I have the same tanks in my Rocket as well. The Rocket has 44 gallons standard, not 48. It totals 54 gallons with the aux tanks, RV4 40 gallons total. I give the long range tanks a big thumbs up. I bet I fly more than any of you guys and use them not only for long XC's but tankering cheap gas. As far as bladder issues go, Gatorade bottles have more than one use! As we say in the F16, fuel is a force multiplier...Smokey

Guys,
I just flew the Bandit home from Texas last week and tested my new Safe Air One ER tanks. I love them! The tanks add 8 gallons bringing the total fuel supply to 40 gallons. I filled them in Carthage TX and flew non-stop to my home strip near Lakeland, FL in 4+00 and landed with 9 gallons left! I didn't feed the aux tanks into my main tanks until the mains showed 1/2 fuel. The ER tanks emptied into the mains in less than 5 minutes. They are installed forward of the spar and extend outboard from the main wing tanks to the tip where the fuel cap door is installed. Upon post flight inspection, the ER tanks fed completely dry.
The tanks were the brainchild of my fellow fighter pilot buds Jeff "Hollywood" Hansen and Chuck "Cheez" Wilson. They installed the prototypes in their RV4's almost 10 years ago and have extensive test data and experience with the system. I look at the tanks as a force multiplier for me as I can tanker fuel onboard at cheap gas stops or if I need a long leg over questionable terrain or where there is no cheap gas, I am covered. The bottom line is it makes your RV4 more capable, period. All of the new RV's have 40 gallons of fuel, you can too..

Overall, a home run for me...

Rob Ray

Smokey, sorry if that read wrong. I was not trying to say that it is not nice to have more fuel, just that you may not be able to carry it. The whole weight issue is the limiting factor on the -4. In the UK the gross accepted by the PFA is 1550.

So my plan is:

Aircraft Target 990
Oil 0
Fuel 192 I hope that is correct for standard tanks.
Pilot 154 Me
PAX 130 the boss
Bags F 20 Mine
Bags R 50 Hers

Total 1536

My trips at gross are two up and luggage into Europe. Her behind needs regular stops to stay happy though.

That leaves a 14 lbs margin for when she (the aircraft not the wife) puts on weight, and I will need some oil! (also, flight guides amaps paperwork etc all add up.) In fact I would like to be lighter than 990 and I think Dayton came in at 933 from memory. My MT c/s prop will weigh a bit though. If I make it in at < 975 I will be delighted. I guess you will reasonably say I will be well under gross if I do, so I could use bigger tanks!

I think in the US you just decide your own gross though, so perhaps its less of an issue.

I have just heard of one newly weighed -4 at 1138. Ouch!

Cheers,

Tom -
I'm in the same boat; new to the airplane & interested in a purchase. If you have a words of wisdom or contacts to impart, I'd be grateful.
Cheers -
Trash
[email protected]

Nice Weldment crack....

Trash,
Welcome aboard. Here's a link to a nice picture of a cracked weldment. Just lean down and look beyond the rudder pedals and you should be able to tell.

http://www.vansairforce.com/community/showthread.php?t=18448

Also, use the search mechanism here to hunt up more info. Of course, specific questions can and will be answered right here.

Personally, I like the airplane to be as simple as possible. You get used to an airplane that's always ready to go when you are and doesn't cost a college education to keep in annual .

Good luck with your search

John

sstspin said:

Tom -
I'm in the same boat; new to the airplane & interested in a purchase. If you have a words of wisdom or contacts to impart, I'd be grateful.
Cheers -
Trash
[email protected]

Click to expand...

Welcome Trash,

I?m afraid I?ve little wisdom to offer other than suggesting that you find someone with RV experience to do an inspection. You?ve already done a lot by coming here, the info in this thread was a big help to me.

Also make sure you or your mechanic has the latest list of service bulletins from the Vans site. They just sent us the updated weldment for the manual elevator trim and a couple of brackets to stiffen the rear seatback.

The biggest problem my partner and I are having so far is transition training. Most available instructors are booked months in advance, so you might want to start lining up someone well before you buy.

When we were looking we found quite a few that were ?not of the highest quality?, so be patient. And of course remember that old adage ?Take a close look at the tails built by first timers?. The fellow that used to share our hanger had to do an extensive rebuild of the tail on his -4 soon after he bought it.

Tom