This will perhaps give you a better answer than can I.
Cobalt wrote:
Fenland_Flyer wrote:
ISHAM
Isham?
Same question…?
As far as I understand, “the Isham STC” is a way to unlimit the 195hp Hawk XP to the 210hp the factory intended it to have, making it equal to the Reims Rocket. The link Fenland_Flyer posted above explains it, Alexis also mentioned the HP difference between the two.
Tomasz,
you can find the TCDS here
Or go to the TCDS search page here and search on 3A17. That will return a list of all models under the same TCDS. But these are also all included in the Rev 47 pdf above.
BTW, you can tell a Reims production by the serial number which starts with FR172… rather than R172…
As mentioned, the Reims Rocket and Hawk XP use the Continental IO-360. The XP version is either the IO-360K or IO-360KB. The B indicates the improved crankshaft which was previously a big problem on the IO-360K. This engine was also used on the Cessna 337. I’ve upgraded the alternator on my XP from the original 38Amp to the 60Amp used on the 337 version of the IO-360. I believe the same engine was also used in early model Cirrus aircraft.
Yes, the SR20 up to very recently had the Conti IO-360 ES, which is 200 hp @ 2700 RPM, so somewhat in the middle between the Rocket and XP engines. Very smooth, but also expensive and too little power for the airframe.
The XP doesn’t have the internal fuel tank and being from Kansas may not have the standard corrosion proofing of the French Reims. OTOH it has rudder trim and 2000 hour TBO, 1500 Hours for the Reims Rocket.
If you don’t need the larger fuel tanks and better useful load of the 182, the XP/Reims Rocket are very good value tourers.
The Cessna Pilots Association produces Cessna model histories. I believe access on their web site to that info is limited to members. But here is a copy of the R172K history, including Reims models… Cessna R172K model history just for this exclusive group. 
Since club membership pays for this type of info, I would ask that it not be otherwise posted on a generally public available personal web site that might have it show up in Google searches.
RobertL18C wrote:
The XP doesn’t have the internal fuel tank
It depends on the version. Referring do the US 1979 model, the standard version is 52gal (26 per side, 49 usable) and might be a bladder tank. The long range version is 68gal (34 per side, 66 usable, with 25gal tabs inside the filler opening) and is definitely an integral fuel tank in a sealed portion of the wing itself.
While the XP doesn’t have the 182’s speed, it does have good range with the long range tanks. A good long-range setting is 10gph which gives 6.5hr to dry tanks @ approx 110KT, which is over 700NM. According to the POH, range is over 800NM @ 50% power and 96-102KT (SL-12’000ft). Of course, that’s over 8hrs which isn’t everyone’s cup of tea.
Corrosion proofing was a factory option in the US, so it may or may not have been done on US production (mine has corrosion proofing).
I had the chance to fly an early model Reims Rocket, a 1968 Cessna FR172F today, for my annual IR checkride.
This one has an MT 3-blade composite prop. Most Rockets im Germany have had their
original 2-blade metals props replaced with these, to reduce noise. Those still with the 2-blade props are now flying in places like Poland…
This one also has the Gomolzig extra muffler to reduce noise further.
A few impressions:
-love the engine of course. On the ground, it feels and sounds beautiful. And in flight, it is also very smooth.
-In flight though, I didn‘t like the sound. On takeoff and initial climbout, the 2800 RPMs make an eery sound. Even with ANR headsets, it doesn‘t feel very quiet. And even in cruise, at 2400 RPM, it sound more like it is doing 2600 RPMs or so. Not very relaxing. Maybe this impression comes from this specific prop, don‘t know…
Cruise performance is ok. In wet rental mode, it did about 120-124KTAS, burning just over 40 litres an hour. I guess that with GAMIs, one could do 110 or so knots at 32 litres or so, which would be just like a regular 172N.
-I wasn‘t so impressed with the climb performance though. I expected it to climb like a homesick angel, bit it was more like 600-700 FPM at 85 knots or so. Again, maybe the prop and/or the muffler costs some power.
Anyway, another interesting and capable type/variant in the logbook.
