DaveB

I have just started building the discontinued GP Cherokee 40. I was planning to power it with the OS-52 4 stroke engine. However, upon examining the drawing, I have a concern the engine is slightly too large to fit properly. It seems to me that with the engine as close to the firewall as possible, the drive washer will extend too far beyond the cowl to look good. It's still not too late to move the firewall back a little, but I would rather avoid that if at all possible.

I realize this is an older plane, but I was hoping someone has built it with the OS-52 4 stroke or similar and what if any problems were encountered.

Thanks in advance for any replies.

DaveB

nickj

I built this a long time ago with mechanical retracts and an O.S. 40 FP. Pretty heavy, and it barely flew. Do you think the .52 4S is enough engine?

Wnuk

I have mine powered with an OS 46FX. Plenty of Power for it. Though I do agree this plane is on the heavy side for a 40 size bird.

Jim

DaveB

I believe the OS-52 is plenty of power to fly the plane in a scale like manner. One of our club members powered the VK Cherokee which is similar in size and weight to the Great Planes model with the OS-52 and it was plenty. According the instruction manual, the weight is 5 1/2 to 6 1/2 pounds and a 40 - 45 2 stroke engine will provide ample reserve power, therefore the 52 4 stroke will be plenty as long as it will fit properly. It's the physical size of the 4 stroke, particularly the length I am concerned about. If the back of the spinner winds up 1/2" ahead of the cowl it just won't look right.

I am hoping someone out there has installed the OS-52 in the GP Cherokee and will post a positive report.

DaveB

jaka

Hi!
I built this GP Cherokee 3 years ago to our club, to serve as club trainer airplane and it is powered with a MVVS .40 engine and flies with a 11x6 APC prop.
It is lightened every were and weights around 2,5kg. It has flaps, controlled by a Hitec Hs 85 servo, ailerons and elevator controlled by Hs 225 servos and throttle with Hs 80 servo.
It uses a 4,8V, NiMh /2300 mAh GP battery and a Futaba "Skyport" 6 channel radio.
Plane was built entirely with Flash CA glue (thin and medium) and is covered with Oracover plastic covering (Oracover even sticks good to the plastic sheet which make up part of the side windows and front window on this plane).
Fuel is and has been for years ; Motul "Micro" 15% all syntetic oil and 5% nitro.
It is very docile aircraft to fly.

Regards!
Jan K
Sweden

DaveB

Thanks for the replies regarding the GP Cherokee.

I was able to see the same plane currently being built that is powered by the OS-52 4 stroke. As I suspected, the engine is a very tight fit, as the rear of the engine is against the firewall and the drive washer barely exits the cowl. Therefore, I will be moving the firewall back 1/2" and that will provide the room needed to install the OS-52 with a little room to spare.

DaveB