Fox Stunt .35 approximate age

[YakNine]

Hi Guys, I have a few Fox .35's and just got one off Ebay its a little different it has the same backplate and head and crankcase as my other engines, the cylinder is different it's not beveled where it goes into the block it also doesnt have the hole in it under the exhaust port, the drive hub is steel and blued like a gun barrel not aluminum and the front prop washer is thick copper and also blued , the piston pin has brass inserts and doesnt use clips, the piston isn't cut for them anyway, The exhaust is wide open with no muffler provisions cast into the block and no divider in the port. I am guessing that this is an older model than the others that I have I cleaned it up and lubed it and it has great compression, if it runs good I think Its going in my shoestring for Foxberg events, I was just curious to its approximate age as its probably older than my original shoestring kit. Thanks T.J.

[Scott B. Riese]

Sounds good. "BIG IRON" Marvin Denny is the expert. Looking back...it could be a 1957-59 engine. HOWEVER, I just don't know. Fox engines have a bad rap...I run FOX 35 with confidence. I think there a great engine. You just have to rub them the right way. Older engines like ALL CASTOR. Newer ENGINES....20% Castor with 5% Klotz with a 10.5x5 bolly at 10000 rpm's. I've have over 800 runs with that combo. And that maybe to much Castor for your area. Flying in the NW we don't have the high heat with the low humidity. Perfect for FOX Engines. Sorry to ramble   

[Bill Gruby]

 A picture of it would help immensly. I can ID it from there.

 "Billy G"   

[Bill Mohrbacher]

The divider and e clips showed up in 1968, so your engine is a 1958 or earlier.  Fox used a taper drive thrust washer until 1953.  In 1953, Fox used an O&R thrust washer.  Yours is blackened steel so your engine is a 1954, 1955, or 1958.
  
The 1958 has bosses cast in between the cylinder fins to stiffen the head bolts. It also has three webs at the front of the crankcase and uses a thick thrust washer and prop washer.  

The 1955 engine has NO bosses in the fins, only one web on the bottom of the case, and uses a thin steel drive and prop washer.  

The 1954 engine has a thin thrust washer and prop washer; the prop washers may have been copper plated and blackened; often they show copper when scratched.  Most important, the 1954 engine has NO webs on the front of the crankcase.

[YakNine]

I will see if my fiancee will let me use her camera, On a closer look out in the sun the drive lug & prop washer are black oxide finished. I am with you Scott I think I was born 3 decades to late I farm part time with old equipment from the 40's and 50's I am a diesel mechanic for the railroad specializing in cranes. I enjoy the old stuff its pretty simple if you take the time to learn the quirks you can learn how to run any thing sometimes even tame them. My Father said I was hard headed and stubborn I prefer "Mechanically Ecentric" I am having fun, I am not hurting anyone , and I am not breaking the bank either, plus I guess the stubborn side likes to prove the naysayers wrong! Thanks T.J.

[YakNine]

Thanks Bill by your description it is a 1958 it has the webs and the bosses. Thanks T.J.

[Leo Mehl]

Sounds good. "BIG IRON" Marvin Denny is the expert. Looking back...it could be a 1957-59 engine. HOWEVER, I just don't know. Fox engines have a bad rap...I run FOX 35 with confidence. I think there a great engine. You just have to rub them the right way. Older engines like ALL CASTOR. Newer ENGINES....20% Castor with 5% Klotz with a 10.5x5 bolly at 10000 rpm's. I've have over 800 runs with that combo. And that maybe to much Castor for your area. Flying in the NW we don't have the high heat with the low humidity. Perfect for FOX Engines. Sorry to ramble    

I agree with Scot about the fox. There is just something special about the 2-4 break on this engine that is different than any other engine. I am running a 50th anniversary fox with hemi head and stuffer backplate with a Randy Smith CNC crank shaft that is actually too loose in the case and the engine performs to perfection. I am also using tounge Muffler. It has plenty of power for a plane with 500 square inches of wing area and weights around 39 to 40 ounces.

[john e. holliday]

I was always told never run a Fox Stunt on more than 500-550 square inch planes.  I think the Thunderbird(original Veco) was slightly bigger.  While watching Jim Kraft fly his Redhead McCoy, someone said it sounded like a Fox.  I replied far from it.    

[Jim Thomerson]

Back in the good old days, when I flew a Fox stunt 35 in a 540 square 48 oz airplane, I paid more attention to setting the needle than I do today with a smaller 27 oz airplane.

[Leo Mehl]

There is something special about the Fox 35 engine that is just right for stunt, but you need to build a plane that is 500 square inches or a little less and keep it around 39 oz. the two four break on this engine is superb. My Arctic fox stunter was designed for the Fox 35 and it has around 480 square inches of wing area and weights 39 oz. This is the perfect size for this engine. It's a great engine that was used to power plane that were actually to large and heavy for this engine. I think we asked too much of this engine in the past.

[YakNine]

Hi Leo do you have plans available for the Arctic Fox, it is a real looker! T.J.