OS .35 Max I, II, and III experience? Who has had any and your opinions.

[frank mccune]

      Hi All:

      I have a like new OS Max I and a friend of mine can hook me up with OS Max III engines to replace my Fox .35 Stunt engines for next season.  Anybody have experiences with these engines in  the past? What were the results?

      What I am looking for is a SPORT engine that will start easily, run consistently and be a joy to use.  In my "Junk Drawer," I have a few foreign engines that has not been run but the quality looks good.  These include OS, ST, and Enya.  I have used these brands of engines in the past, and have liked the way that they perform.

      I have used the newer OS .40 FP in both Diesel and glow form and they are a fine engine. However, I just wish to try something different.

      In my large built up Stunt planes, I am going to install HP .40 engines during the Winter.  In my humble opinion, these engines are the cat's pajamas for this type of Sport flying.  I plan to list my cast offs on the classified list during the Winter.  It is past time to clean house!

      Comments or suggestions?

                                                                                                        All of the best,

                                                                                                        Frank McCune

[Phil Spillman]

Hi Frank, Long ago in a galaxy far away I used several OS III .35's and .29's. They were quite powerful for the day early to mid-60's and ran quite well without rework required! On the negative side the crankcases were very wide and the bolt patterns didn't match anything of that era! However if powered by adequate castor oiled fuel they lasted quite well. remember there will be no replacement parts nor mufflers available from any ready source save run out flea market or internet auction sources! Why not sell of the bunch and buy a reliable modern engine or at least one of modern structure to use more modern fuels? That said I am looking to get back a Forester .35 with a straightened crank shaft soon! Might fly it might not!

I have had much fun flying and competing with an old Enya .45 model 6001 with a strap on muffler! I set the needle valve three years ago and haven't touched it since! It just keeps on purring around on my well flown Viking in OTS! If you'd like to try one let me know I know a guy who just might sell you one! 

Phil Spillman

[Steve Helmick]

Had a Max III .35 on my first combat models. Never got a clock on it, but I'd bet $ that it was capable of 110 mph on pressure, Missile Mist and a 9-7 Tornado nylon. Doesn't seem like  it would be a good serious stunt engine, but would be fun on a large-ish sport model...and I'm not having much luck thinking of a suitable example, other than the (not GMA) Aldrich "Acrobat"...I think that was the name. Straight LE, tapered wing, trike, no flaps, upright engine. "Aerobat", maybe. MAN, late '50's or very early '60's. Barry Baxter doesn't have it. Leonard might.

FWIW, the one I got had a huge steel chip in the crankshaft bore. Luckily, I had pulled the backplate off and removed it.    Steve

[Norm Furutani]

FWIW, the Max III OS's are very desirable for the Nostalgia Gas FreeFlight event. So there is a market for them $$.

Norm

[Ken Burdick]

I have a nice one in the shop for Combat Graffiti. When I was a kid, I bought an os .29 111. It was pretty fast but I had a heck of a time starting it back then.....

[Dennis Leonhardi]

Hi Frank, Long ago in a galaxy far away I used several OS III .35's and .29's. They were quite powerful for the day early to mid-60's and ran quite well without rework required! On the negative side the crankcases were very wide and the bolt patterns didn't match anything of that era! However if powered by adequate castor oiled fuel they lasted quite well. remember there will be no replacement parts nor mufflers available from any ready source save run out flea market or internet auction sources! Why not sell of the bunch and buy a reliable modern engine or at least one of modern structure to use more modern fuels? ...
Phil Spillman

I'll offer a very strong second to Phil's comments.  There is a good market for the old Max engines and I don't consider them to be a very good SPORT engine at all.  I say that having used many of the Series I through III engines for combat back in the day.  They're relatively big, heavy, difficult to find sturdy mufflers for, and parts are almost non-existent.

I'm not particularly an Enya fan, but if you look for parts on eBay, for example, you'll find mufflers, gaskets, screws and replacement needle valves are pretty available for them, whereas the same parts for the old Max engines are rare ...

The newer OS engines are pretty popular - consider that many of the parts for the Magnum GP, OS FP and Thunder Tiger GP .40 engines are interchangeable, and that's a whole different world.

Just my penny's worth (half-price today!).

Dennis

[Dennis Moritz]

I've a Mark 35 111 from my youth. Big Venturi. Powerful. High rpm timing far as I can tell. Only run on the bench.


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[EddyR]

I agree with the above comments. I had two of the 35"s and used one for combat with the restrictor removed and case pressure. It was as good as anything else  at the contest I went to. Later I used one for class C free flight on a Sandy Hogan. I was a lot better than the K&B green heads that most were using.
Ed

[Brian Hampton]

I used to use a Max III but it's so long ago I can't remember how easy it was to start however not all that long ago I was giving a Max II a bench run and luckily I had my thermocouple attached because soon after it started the temperature skyrocketed up past 300F. Oops, I was using my usual 20% all castor (no nitro) fuel so I switched to my 25% all castor and then all was well. I've got both the small and large crank Max II's but I think I was running the large crank version. I believe they were called the Combatnik in America.