Isham aircraft cessna R172K 210 Horsepower Product Catalog Page

Over 400 Cessna R172K Hawk XP owners are flying with the 210 HP Continental engine. Our 210 horsepower STC modification conversion provides maximum performance for the Cessna 'Hawk XP.  The high performance version of the XP has a proven reliability, kit installation is simple and no category restrictions are placed on the airplane's original type certificate. The modification is fully approved by the FAA for both the landplane and seaplane versions. The STC covers Edo and PeeKay floats and the 210 horsepower is also approved by Wipaire in their AFMS.  The Hartzell Top Prop is approved by Hartzell for their 3-blade propeller in combination with this 210 horsepower conversion.


The steps required for the conversion in simplified form are:

1.  Overhaul and remark the Manifold Pressure/Fuel Flow gauges.

2.  Rebuild the propeller governor.

3.  Change the low pitch stop on the propeller (simple change but must be a propeller mechanic or shop).

4.  Test run and make any adjustments necessary. 

5.  Remark engine data plate and complete 337 forms.

All of the work for your 210 horsepower Cessna R172K Hawk XP aircraft modification can be accomplished by most FBO's. Installation time is approximately four to six hours. The kit requires overhaul and new dials installed on your mechanical tachometer and manifold pressure/fuel flow gauge, new fuel flow placard, STCs, installation manual, instructions and FAA approved airplane flight manual supplement (AFMS). 

Shorter takeoff (490'/990' over 50').

The Cessna R172K Hawk XP has adequate power at 195 horses. That is why the increase to 210 horsepower causes such a dramatic difference in takeoff performance. All of the added power is destined to quicken acceleration. This shortens the distance from the start of the takeoff roll to the point takeoff speed is reached. The 210 horsepower makes the airplane sound and accelerate like a Cessna 210! Even under severe takeoff conditions the airplane jumps off the ground with an immediate and positive rate-of-climb.

Increased rate-of-climb (1150 fpm @ 81 KIAS).

As with takeoff acceleration, the additional power provided by the 210 horsepower all goes to increase the rate-of-climb after lift off. The initial climb after rotation is much more positive. The rate-of-climb increase significantly reduces the time it takes to reach cruise or ATC assigned altitude. This reduces pilot workload (less climbing maneuvers) to reach required altitudes when crossing controlled airspace.

Less fuel burn and shorter time to altitude.

Because the shorter takeoff and increased rate-of-climb requires less time, this results in less fuel burn from the start of the takeoff roll until reaching climb altitude.

Improved decent capability.

At low pitch (high RPM) the propeller works like an air brake. The power off decent rate is dramatically quicker at 2800 RPM than at 2600 RPM. This feature can be controlled simply by setting the prop control in high RPM if a rapid or emergency decent is needed, or by setting it at 2600 RPM for a normal decent approach.

Improved ground handling.

The standard R172K Hawk XP requires constant braking to hold the taxi speed down at engine idle. The 210 horsepower conversion changes the propeller low pitch stop setting causing the blade to "flatten". At engine idle this results in less forward pull by the prop. The airplane taxi's at a safe and comfortable speed without the need to constantly ride the brakes. Also, this reduces heating and wear on the brake pads and discs, lowering maintenance costs.

Ability to log high performance pilot in command time under FAR 61.31.

Because the airplane is over 200 horsepower the pilot may log his time as high-performance according to FAR 61.31. This is very beneficial to owners, family members or others flying the aircraft to build time for additional ratings or career opportunities.

Improved STOL and emergency go-around capability.

How much difference can 15 horsepower make? A lot! The extra power all goes to added takeoff acceleration and climb performance. You really have to fly it to believe it, but the difference is a very significant improvement to the R172K.

Near Cessna 182 Skylane performance at a fraction of the cost.


You will receive maximum performance from your engine. The 210 horsepower is attained by removing the "D-rating" that Cessna placed on your airplane's engine. The 210 horsepower XP has a proven reliability. In essence, the modification makes the XP nearly identical to Cessna's "Reims Rocket" built at the company's plant in Reims, France, and the U.S. Military T-41B. Both of these Cessna airplanes have the full 210 horsepower capability of the IO-360 engine. Over 25 percent of all Cessna R172K airplanes have this conversion installed.

What does Continental Motors say about the conversion?

". . . no affect on the difference in structural integrity or airworthiness . . . Thus the IO360K should also provide excellent operation and service with a take-off rating of 210 HP at 2800 rpm."

Technical Description.

STC SE1436CE and SA1437CE approve the conversion of the Cessna R172K to operate at 210 horsepower. The STC's are applicable to the following:

  • Continental IO-360-K

  • Continental IO-360-KB

  • Cessna R172K landplane (all)

  • Cessna R172K floatplane