Van's RV-4

Dick VanGrunsven flew the first RV-4 prototype in 1979. The design was a logical step up from the single-seat RV-3 that put Van's on the map in the early 1970s. Tandem seating, conventional gear, a small Lycoming, and an airframe that could be built from plans by a motivated amateur in a single-car garage. Kits started shipping in 1980, and by the late 1980s the RV-4 was the most popular two-seat kit in the United States.

What set the RV-4 apart from earlier homebuilts was build accessibility. The plans were complete and the construction was straightforward riveted aluminum. There were no obscure materials, no exotic forming techniques, and no engineering that demanded prior aviation experience. EAA chapters across the country took on RV-4 builds as group projects. The fleet grew fast.

Van's eventually moved past the RV-4 with the side-by-side RV-6 in the late 1980s and the RV-7 in 2001. New kit sales of the RV-4 tapered off as builders gravitated toward airplanes with side-by-side seating, larger fuel tanks, and more interior room. As of mid-2026, Van's reports roughly 1,500 RV-4s flying, with new completions still trickling in from long-running projects.

Performance depends on engine choice more than airframe condition. A 150 hp O-320 RV-4 with a Sensenich metal fixed-pitch prop cruises at 145 to 155 KTAS on 6 to 7 gph. The 180 hp O-360 version with a Hartzell constant-speed prop adds 10 to 15 knots and brings cruise burn up to 7.5 to 8.5 gph. A few RV-4s run angle-valve IO-360s in the 200 hp range, which gets cruise into the 175 KTAS area but adds weight and complexity that doesn't suit the airplane well.

Useful load is tight. A typical 180 hp RV-4 with a constant-speed prop has about 480 to 520 pounds of useful load. Full fuel is 32 gallons, or about 192 pounds. That leaves around 300 pounds for two adults and their bags, which works for two slim pilots and a flight bag but doesn't work for two adults with camping gear. The cabin is narrow tandem. The rear seat is small. If you regularly fly with a passenger, the RV-4 is the wrong choice.

The Lycoming O-320 (150 hp) and O-360 (180 hp) are the canonical engines. Both are parallel-valve four-cylinder Lycomings with a published TBO of 2,000 hours per Lycoming Service Instruction 1009 BE, though that number is advisory in experimental service. About half the RV-4 fleet runs an O-320 and most of the rest run an O-360. A small number have IO-360 or IO-390 installations that are more capable but rarely seen in the used market.

Field overhaul of an O-320 runs $25,000 to $38,000 in 2026 at a name-brand shop. The O-360 is in a similar range, slightly higher on the upper end because of valve work. Owner-assisted overhauls are legal in experimental service and can cut costs by 30 to 40 percent in labor savings. The RV community has a long memory and detailed forum threads on doing this well.

Propeller choice splits the fleet. A Sensenich metal fixed-pitch prop is the cheap, simple, reliable choice. There's no constant-speed TBO to track, and overhaul is a few hundred dollars on condition. A Hartzell constant-speed prop adds 5 to 8 knots of cruise and improves takeoff and climb noticeably, but it brings a 2,400-hour or six-year overhaul cycle per Hartzell Service Letter HC-SL-61-61Y Rev 12. That overhaul runs $1,500 to $3,500 in 2026.

The RV-4 is one of the cheapest fast airplanes you can own legally. The math splits along the same builder versus buyer line as the rest of the Van's line.

If you built it: fuel dominates the hourly cost at $35 to $50 per hour depending on engine and fuel price. Engine reserve is $12 to $19 per hour. Prop reserve runs about $1 to $2 per hour for a fixed-pitch Sensenich or $1 to $3 per hour for a Hartzell constant-speed. Airframe maintenance reserve is $6 to $12 per hour, low because you know the airplane and can do most of the work. All-in cost at 100 hours a year runs $80 to $115 per hour, plus annual fixed costs of $2,500 to $5,000.

If you bought it used: you're paying an A&P for the annual condition inspection and you're paying for any work outside your skill set. Realistic all-in is $100 to $145 per hour at 100 hours a year. Insurance is meaningfully higher than the original builder paid because underwriters give discounts to repairman-certificate holders.

Acquisition cost in mid-2026 runs $35,000 to $55,000 for a high-time RV-4 with original avionics, $65,000 to $95,000 for a well-maintained example with a glass panel and current paint. Low-time examples with strong build documentation and recent engines occasionally trade above $100,000. The RV-4 is the cheapest way into the Van's family by a wide margin.