Author Topic: Which OS Max 35 is the one for stunt? (Read 6171 times)

Andrew Tinsley · « **on:** January 24, 2016, 02:52:42 AM »

I have been told that there are various Marks of the old OS Max 35. I wasn't sure that I believed this as I have never noticed any difference between the engines I have. However I have just been given one with an offset plug. So there are different ones out there. Which is the best for stunt and how would I recognise one when I see it?

Thanks,

Andrew.

RandySmith · « **Reply #1 on:** January 24, 2016, 10:27:22 AM »

Quote from: Andrew Tinsley on January 24, 2016, 02:52:42 AM

I have been told that there are various Marks of the old OS Max 35. I wasn't sure that I believed this as I have never noticed any difference between the engines I have. However I have just been given one with an offset plug. So there are different ones out there. Which is the best for stunt and how would I recognise one when I see it?

Thanks,

Andrew.

POST a picture of your stunt engine, and the one with a angled plug head, does it have a steel finned sleeve?

Randy

Andrew Tinsley · « **Reply #2 on:** January 24, 2016, 10:42:01 AM »

Hello Randy,
I always have difficulty when trying to post a picture on the forum, even though I have been able to compress it to below the pixel count required. I shall have another try and see if I can manage it!

Thanks,

Andrew.

RandySmith · « **Reply #3 on:** January 24, 2016, 11:58:45 AM »

this is the 35S stunt engine from the 1960 and 70s

Andrew Tinsley · « **Reply #4 on:** January 25, 2016, 08:30:52 AM »

Hello Randy,
Still having problems with photos, so thanks for your photo of what I think of as the old OS Max 35. This is the one prior to the FP series, I believe. It has a one piece die cast crankcase with a drop in liner and the plug in a central position. The engine that made me post, is an earlier type with a solid, finned steel liner and the plug is displaced towards the transfer side and it isn't canted, but upright.
I have read stories about stunt fliers going from Fox 35s and using the new OS Max 35, which had more power. It gave good stunt runs when new and tight, but as things settled down, it could exhibit the dread runaway. It also had a reputation for eating rods.
I assume the engine I have is this early type? If so which is the better engine for stunt application, the solid steel finned early version or the later drop in liner type. I want to build a classic plane using a stunt Max 35, hence the query, it is just a nostalgia exercise! so nothing serious!

Regards,

Andrew.

RandySmith · « **Reply #5 on:** January 25, 2016, 12:12:51 PM »

Quote from: Andrew Tinsley on January 25, 2016, 08:30:52 AM

Hello Randy,
Still having problems with photos, so thanks for your photo of what I think of as the old OS Max 35. This is the one prior to the FP series, I believe. It has a one piece die cast crankcase with a drop in liner and the plug in a central position. The engine that made me post, is an earlier type with a solid, finned steel liner and the plug is displaced towards the transfer side and it isn't canted, but upright.
I have read stories about stunt fliers going from Fox 35s and using the new OS Max 35, which had more power. It gave good stunt runs when new and tight, but as things settled down, it could exhibit the dread runaway. It also had a reputation for eating rods.
I assume the engine I have is this early type? If so which is the better engine for stunt application, the solid steel finned early version or the later drop in liner type. I want to build a classic plane using a stunt Max 35, hence the query, it is just a nostalgia exercise! so nothing serious!

Regards,

Andrew.

Hi Andrew
The one I post a picture of is it, this is one of the best stunt motors made, and Yes they were tough on rods because 1- people used the wrong fuel 2- the rod was soft alum. with no bushings, and 3 the stock muffler had a very small hole in it, and some ran them too hard and too hot.
I have CNC rods for this engine that are much better quality al. not bushed but far better than stock. I also have many parts for the 35S
This is a light engine and is better than the steel finned one for a stunt engine
I made about 165 of these with my bushed rods, anodized heads in red blue gold black and natural, some had heat cycled P/S in them some had ABC setups in them, I see the every now and them on Ebay

Randy

rustler · « **Reply #6 on:** January 25, 2016, 02:10:40 PM »

Concerning the FISE Max engines, the pic. is of the Max-S 35. I believe this was GMA's favoured engine for the Nobler once silencers came in. Even better if you have a Bri-Stunt ABC p/c fitted.
After this, the favourite is the Max-II 35. This is identified by not(!) having Max-II on the transfer, and exhaust drilled to take the O.S. silencer. Max-I has it written on the side, and not drilled. The heavier Max-III has it written, is drilled, and is a bit wild for stunt.
There's also the heavier shiny case engines, usually for combat and rat race.

Andrew Tinsley · « **Reply #7 on:** January 25, 2016, 03:33:47 PM »

Thank you Ian,
I suspected that the lineage of the OS 35 was a bit more complex than I thought. I have a Bristunt ABC P/L awaiting the correct version of the OS 35!

Regards,

Andrew.

Brian Hampton · « **Reply #8 on:** January 25, 2016, 04:46:49 PM »

Andrew, your engine is a Max-III with the offset plug. The Max-I was marked on the transfer and had a central plug. Then came the Max-II still with central plug but, as mentioned, wasn't identified with markings although strangely the Max-II .15 WAS marked! However there are two versions of the Max-II 29/35 with the later version having a larger crankshaft which was carried over into the Max-III. This larger crank version was called the Combatnik in America but it's not shown in the OS timeline. The small crank version is easily identified by having a machined band on the crankcase behind the prop driver while the Combatnik crankcase looks identical to the Max-III.

rich gorrill · « **Reply #9 on:** January 28, 2016, 12:33:29 PM »

Not trying to hi-jack the thread, Randy could you elaborate on the proper fuel for this engine. I assume you will recommend a high oil content fuel as it is an older engine like the fox 35.

Thanks,

Rich

Dane Martin · « **Reply #10 on:** January 28, 2016, 12:41:36 PM »

Quote from: rich gorrill on January 28, 2016, 12:33:29 PM

Not trying to hi-jack the thread, Randy could you elaborate on the proper fuel for this engine. I assume you will recommend a high oil content fuel as it is an older engine like the fox 35.

Thanks,

Rich

Good question! I would like to know also. I'm building a boxcar chief for my wife and will be powering it with this os engine

RandySmith · « **Reply #11 on:** January 28, 2016, 03:30:42 PM »

Quote from: rich gorrill on January 28, 2016, 12:33:29 PM

Not trying to hi-jack the thread, Randy could you elaborate on the proper fuel for this engine. I assume you will recommend a high oil content fuel as it is an older engine like the fox 35.

Thanks,

Rich

Hi Rich

best to use 1/2 synthetic/castor blend at 25 to 28% oil, do NOT run low oil fuel in these as the rod will suffer quickly

you can read the fuel article pinned at the top of this forum for more

Randy

rich gorrill · « **Reply #12 on:** January 29, 2016, 06:34:12 AM »

Thanks Randy.

Rich

RknRusty · « **Reply #13 on:** January 30, 2016, 10:23:01 PM »

I just recently started using a Max-S 35 on my Goldberg Shoestring, and I'm impressed.. It's the best 4-2 breaking engine I've ever flown. As noted, you will cook it with a lean run, but it's so easy to tune, it shouldn't happen unless you get a fuel clog. I use Powermaster 10/22.

If you want to hear it run, watch this, it's a thing of beauty. No muffler. 11x6 Master airscrew.

Bob Zambelli made the venturi for me. If you need the details on it I'll measure it for you.
Rusty

frank mccune · « **Reply #14 on:** January 31, 2016, 05:41:04 AM »

Hi Rusty:

Is not an 11x6 a bit of a load on the O.S .35S?

I enjoy seeing your vids. Keep them coming.

Be well,

Frank McCune

RknRusty · « **Reply #15 on:** January 31, 2016, 06:24:18 AM »

Quote from: frank mccune on January 31, 2016, 05:41:04 AM

Hi Rusty:

   Is not an 11x6 a bit of a load on the O.S .35S?

   I enjoy seeing your vids. Keep them coming.

   Be well,

   Frank McCune

You're right Frank, it's a 10x6. Thanks for catching that.

With camera in hand, I'm off to fly this morning.
Rusty

Akihiro Danjo · « **Reply #16 on:** January 31, 2016, 07:53:53 AM »

Quote from: frank mccune on January 31, 2016, 05:41:04 AM

Hi Rusty:

Is not an 11x6 a bit of a load on the O.S .35S?

Unmuffled 35S may be able to turn 11".
I have never seen unmuffled engines that are larger than .15 running these 40 years.

Aki

RknRusty · « **Reply #17 on:** January 31, 2016, 07:04:53 PM »

Quote from: Akihiro Danjo on January 31, 2016, 07:53:53 AM

Unmuffled 35S may be able to turn 11".
I have never seen unmuffled engines that are larger than .15 running these 40 years.

Aki

Aki, see the post right above yours... I was mistaken, Frank caught it. It is a 10x6.
Sorry for the brain fert.

I took it to the field today, but it was too swirling windy to fly that little Shoestring. My fatass Cardinal had no problem though.
Rusty

Author Topic: Which OS Max 35 is the one for stunt? (Read 6171 times)

Andrew Tinsley

Which OS Max 35 is the one for stunt?

RandySmith

Re: Which OS Max 35 is the one for stunt?

Andrew Tinsley

Re: Which OS Max 35 is the one for stunt?

RandySmith

Re: Which OS Max 35 is the one for stunt?

Andrew Tinsley

Re: Which OS Max 35 is the one for stunt?

RandySmith

Re: Which OS Max 35 is the one for stunt?

rustler

Re: Which OS Max 35 is the one for stunt?

Andrew Tinsley

Re: Which OS Max 35 is the one for stunt?

Brian Hampton

Re: Which OS Max 35 is the one for stunt?

rich gorrill

Re: Which OS Max 35 is the one for stunt?

Dane Martin

Re: Which OS Max 35 is the one for stunt?

RandySmith

Re: Which OS Max 35 is the one for stunt?

rich gorrill

Re: Which OS Max 35 is the one for stunt?

RknRusty

Re: Which OS Max 35 is the one for stunt?

frank mccune

Re: Which OS Max 35 is the one for stunt?

RknRusty

Re: Which OS Max 35 is the one for stunt?

Akihiro Danjo

Re: Which OS Max 35 is the one for stunt?

RknRusty

Re: Which OS Max 35 is the one for stunt?