Magnum 36: I'm a Believer!

At a contest last weekend a friend was running a Mag 36 in his rather heavy Prowler. Strangely enough, he was running a 10-6 prop in a wet 2 cycle. Lap times were 5.1-5.2 and it motored through some nasty wind and turbulance with ease. He got hip to the motor 'cuz I told him about glowing reviews here on the SSW forum.

Over a year ago Dave Cook made some intakes for these engines for Warren T & Billy W . . . word came back that they ran like an AeroTiger, only downside was the weight.

Never saw one run 'till last week. I ordered one upon arriving home that evening.

LAST EDITED ON Aug-08-03 AT 07:57 PM (CDT)
 
Be sure to get the square cylinder version, XL .36AII. These weigh right around 8.25 oz as shown, depending on the venturi material and NVA selected. The round cylinder Magnum .36 at least seems heavier, but may work ok. The 80mph Combat guys like that version around here. Steve

LAST EDITED ON Aug-08-03 AT 10:33 PM (CDT)
 
Some of my customers use that engine for a local racing event called Warbird. I know a trick to make those engines put out alot more power. But, I guess if a stunt flier needs more power he can just use a bigger venturi.

>At a contest last weekend a friend was running a Mag 36 in
>his rather heavy Prowler. Strangely enough, he was running a
>10-6 prop in a wet 2 cycle. Lap times were 5.1-5.2 and it
>motored through some nasty wind and turbulance with ease. He
>got hip to the motor 'cuz I told him about glowing reviews
>here on the SSW forum.
>
>Over a year ago Dave Cook made some intakes for these
>engines for Warren T & Billy W . . . word came back that
>they ran like an AeroTiger, only downside was the weight.
>
>Never saw one run 'till last week. I ordered one upon
>arriving home that evening.

Put a more normal prop on it. and it will *really* wake up!

On mine, I retimed the crank to 35ABDC (open) -> 65ATDC (close), took out the carb, fed the fuel in through the side of the intake (drill and tap for a 6-32 DuBro fuel nipple), used a remote needle and bladder tank, 25% nitro (SIG fuel), and Taipan 8x6 prop.

Ran about the same as a really good Fox Mark IV (wasn't quite up to Nelson power, but I still pulled kills on a bunch of people at the 2000 Nats), until the crank broke.

That's the problem with those pacific rim engines, the crank is soft.

Depends which ones. Ever try to carve a OS Max .25FSR crank? It'll wear your dremel stones down to a nub.

To be fair, the Magnum was never designed to run at 20-22K. Look at the size of the crank - 13mm vs. 15mm for the Mark VI and 17mm for the Mark VII and Nelson.

>Depends which ones. Ever try to carve a OS Max .25FSR crank?
>It'll wear your dremel stones down to a nub.
>
>To be fair, the Magnum was never designed to run at 20-22K.
>Look at the size of the crank - 13mm vs. 15mm for the Mark
>VI and 17mm for the Mark VII and Nelson.

I think you hit the real point here, Iskandar. You ground the crank and then wound it up to an rpm it was never originally intended to take. So, if you are experiencing failures, you merely access the risk based on what you are doing and do not lay the blame on "inferior construction".

These engines are well made for what they were designed to do, and any engine that is run well beyond the limits of its original design could experience failure. The hot drag racers have to rebuild their engines after every 1/4 mile run, and they still experience failures in that some don't make it that far. But if it gets you the performance you want and the failure rate is acceptable in your eyes, I see no problem in your doing what you do. Hey, even "Tim the Tool Man, Taylor" experienced failures once in a while (well, a lot of the time, but we won't go into that.)

>Ran about the same as a really good Fox Mark IV (wasn't quite up to Nelson
>power, but I still pulled kills on a bunch of people at the 2000 Nats)

Jeff & I have been running a couple of stock (round head) XL-25's in some speed limit planes. One of those is really way outside that zone now, though. Sunday, on 10/22 fuel, with an APC 8-4, it was clocked at 5.65 for two laps on all three of its flights. The speed chart I had with me for what I consider "mid-range" stops at 88 mph. This one was doing about 91 mph, I am interpolating (yes, I have another chart that goes up for faster speed, just haven't loaded Excel this morning . . )

It was very quick for a 25.

.
Kiwi

The Magnum .28s I've modified (with the same mods as the .36) work REALLY well. Haven't had one break yet, and they're more powerful than any other .28 I've tried (I've admittedly stayed away for the high dollar ones).

In Fast trim, I use a wide open venturi, Taipan 7x6 prop. In Speed Limit, it has to be throttled down some (about 1/4" venturi), even with the Top Flite 9x4s cut down to 8x4. Pulls real nice through the turns. WAY too fast with a Taipan 8x6 (even choked down).

e was the weight.
>>
>>Never saw one run 'till last week. I ordered one upon
>>arriving home that evening.
>
>
> Put a more normal prop on it. and it will *really* wake
>up!

Brett;

I'll bite. What is your recommended prop/venturi/fuel setup for this engine?

>e was the weight.
>>>
>>>Never saw one run 'till last week. I ordered one upon
>>>arriving home that evening.
>>
>>
>> Put a more normal prop on it. and it will *really* wake
>>up!
>
>Brett;
>
>I'll bite. What is your recommended prop/venturi/fuel setup
>for this engine?
>
>Bob

Same one Phil is using - it was posted a while back. It's not a 10-6!

http://clstunt.com/cgi-bin/dcforum/dcboard.cgi?az=read_count&om=3652&forum=DCForumID1

10.5-11.25 diameter, 3-4.25" of pitch.

Yeah, I was pretty shocked that imy friend was using a 10-6 on the Magnum. I won't even try that. I have great luck with an ancient iron piston 40FP running an 11.5-4.

Seems like that kind of motor will be happier, put out more power & be more stable at a higher RPM.

>>
>>I'll bite. What is your recommended prop/venturi/fuel setup
>>for this engine?
>>
>>Bob
>
> Same one Phil is using - it was posted a while back. It's
>not a 10-6!
>
>http://clstunt.com/cgi-bin/dcforum/dcboard.cgi?az=read_count&om=3652&forum=DCForumID1
>
> 10.5-11.25 diameter, 3-4.25" of pitch.

Brett;

Thanks. Got that earlier. I was curious if more development work had been done and if so, had recommended setup info changed.

It does make one wish that someone made a mass produced 11x3.5 or 12x3.5.

My Magnum .36 is set up on a Brodak Warbird Profile with a 10x4 Grish
Black Magnum 3 blade prop ,venturi is .250 with stock everything, no extra head gaskets. It runs like a charm about 9800-10000 rpm fast
four cycle all the way. I love it. By the way I got my needle valve
assembly and venturi from Byron Barker. This is a great little engine
Try it you will like it! Walter Hicks.

P.S This one has a muffler no pipe still runs well!

>My Magnum .36 is set up on a Brodak Warbird Profile with a
>10x4 Grish
>Black Magnum 3 blade prop ,venturi is .250 with stock
>everything, no extra head gaskets. It runs like a charm
>about 9800-10000 rpm fast
>four cycle all the way. I love it. By the way I got my

Walter;

You are right. The Grish three blade 10-4 is a great prop. Regrettably, I can no longer get any and it appears that Grish is no longer producing. I am down to my last one... <sniff>.

Ah, well...

How about a Carbon Fiber knock off of this prop? Any interest? Or would it be easier to use a Eather of appropriate size?

After running several props on my new plane over the weekend, including APC, and a couple of expensive hand made CF props, I was amazed at the perfomance of the Tornado 11-4. I went back to it for the comp flights and it did fine. At 1.49 or so, I'll really miss them!

>How about a Carbon Fiber knock off of this prop? Any
>interest?

Yep, I'm interested in a 10-4, 10-6, and 11-4.

>Or would it be easier to use a Eather of
>appropriate size?
>Curt

It is only easier, to me, to use the Eather/Bolly props because they are somewhat available. However, the cost can be prohibitive for these to guys like me who have to stick to a modeling "budget". Unlimited pockets make for great equipment, but a lot of us have to "pick and choose" where we spend our money.

FWIW, the best set up I have ever used on my T-Bird II with a '70's Fox 40 is a 10-6 Grish 3 bld.

If a "copy" could be made that was inexpensive, it could sell like the proverbial "hot cakes", IMHO.

Bill

Iskandar,

I was ready to believe you until the prop in use was mentioned. Look, I've got four "really good" Mk IV Foxes doing nothing but laying at the bottom of a kerosene-filled bucket. None of them are so weak that I could possibly use a Taipan 8-6 prop. Good props, no doubt of that. But they also shed blades with fair regularity.

Your Magnum 36s might be "good" motors. But nothing more than that.

Well, I used Taipan 8x6s on my Mark IVs back then and they didn't shed any blades. Then again I didn't have access to Brasher cranks, AAC liners and all that good stuff. "Good" here means good out of the box (or Doc Passen butchered, at the best).

I wouldn't dare use the Taipan 8x6s on my Mark VII or Wylie, though they seemed to hold up OK on a Mark VI. I was using those Master Airscrew Scimitars, mostly, the last few years I flew Fast. Never did own a Nelson. Hmm.. Come to think of it, I might have been using those on the Magnum at the 2000 Nats. Can't remember, exactly.