Magnum 36 question

Is the current offering dubbed Magnum 36 XLS by Hobby People for $69 the same basic engine touted by Granderson and others?
What is the approximate actual weight of the engine? Hobby People says 12 oz with muffler which sounds heavy-say 9.5 to 10 with tongue muffler.
The Granderson thread seems to be lost as I am unable to locate it with the search function.

Hi there; THats the engine you want. Phil now has a lot of them and I have only two for now but more are pending.The weight of mine with no muffler and a Aero venturi and N.V.A.is 7.83 ounces.I have been using a pipe,like Phil, but am preparing to use one pipeless in an Oriental same as Mike Haverly used all year,as well. Well made engines with maybe a question about the bearing quality. Bearings are cheap and available however. MY first bearing failure occurred after about 320 flights.It is hauling a 57 oz.Saturn very nicely,on a pipe.On the Oriental it may even be overkill. Not an engine to lug down. THey need a 3" to 4" pitch. I use about 4 ounces per pattern of 10%. Keith V

I know this is a stunt forum, but has anyone tried these for combat? Would they be a good modern replacement for a Fox combat Special without the investment of a Nelson?

>I know this is a stunt forum, but has anyone tried
>these for combat? Would they be a good modern replacement
>for a Fox combat Special without the investment of a Nelson?

I "think" Isky has brought the usage for these concerning combat.

I've been racing various .36 engines for years. The magnum, even in fully modified form, will not even equal the power of a fox MK3. If you modify then rev the magnum where it wants to make power the soft crankshaft will break. A modified Fox is also prone to failure of the rod big end bushing, front bearing cage and crankshaft. A nice alternitive engine is the K&B 5.8 which holds together nicely and needs less mods to reach it's full potential.

Fox Mk 3:

Can't speak for the rod bushing, never had a problem. The main bearing should be replaced with a Fafnir. Fafnir races are riveted, instead of using bent tabs, and will not break. This mod was needed on G21's, too - although they would not fail as soon. The crankshaft would snap at the counterweight because of hydrogen embrittlement. Howard Rush suggested it way back when the Mk3 first came out. Heating the shaft to 400-500 degrees for an hour or two, and letting it slowly cool overnight, would "boil" the hydrogen out. It would not break after that. I even did a Materials Science lab report about it (going to college at the time), and confirmed with Duke Fox the particular steel used. There were documented studies that showed that type of steel was prone to hyd. embrittle.

Thanks for the word on the Magnums - guess that explains why I never saw or read about them.

>I've been racing various .36 engines for years. The magnum,
>even in fully modified form, will not even equal the power
>of a fox MK3. If you modify then rev the magnum where it
>wants to make power the soft crankshaft will break. A
>modified Fox is also prone to failure of the rod big end
>bushing, front bearing cage and crankshaft. A nice
>alternitive engine is the K&B 5.8 which holds together
>nicely and needs less mods to reach it's full potential.

Yup, pretty much what I found out. I did use it to get four kills at the Nats, though, before the crank gave way.

Incidentally, quite a few people use it in Speed Limit, where it will last a while using a small venturi. But a .28 or .25 would be better, unless you plan on using elderly Fast Combat planes, in which case the .36 is better.

being an elderly Combat kind've person, is the TT 36 any better?

>The weight of mine with no muffler and a Aero venturi and N.V.A.is 7.83 ounces.

Good info-thanks Keith. I am not familiar with the Aero venturi and needle valve. Do you also have the approximate inside diameter of the venturi and spray bar? It appears the Magnum would use a spray bar mounted through the original carb hold in screws like the OS FP/LA series and I would plan to use a .155 ST needle valve assembly, or better still, the similar assembly done by Scott Riese which is even better.

LAST EDITED ON Oct-18-04 AT 10:59 PM (CDT)
 
I'm pretty sure Keith V. is ref'ing the Randy Smith "P.Aero" parts. I just can't figure out how his engine is so light, 'cept maybe no glowplug. Mine is around 8.2 oz with a Delrin venturi. It could be lightened, but there's not much weight there, anyway. I weighed mine on an Ohaus Triple-Beam Balance, which is trustworth to a tenth of a gram. About any brand of tongue muffler will bring it in under 8.75 oz. Steve

Both the RO Jett 36 and the Aero Tiger 36 use AAC construction which makes them a little lighter.

Greg is referring to the RO-Jett modified Magnum XLS .36 and the Randy Smith modified Thunder Tiger Pro .36, both use AAC P&L. However, Keith's Magnum is box-stock except bearings, venturi and NVA, as is PTG's and Mike Haverly's, FWIW. I believe Mike is using an RSM tongue muffler (a Fox .35 unit fits). I made some venturis for PTG (.240" or smaller), and Mike said he was using a .257" (F drill) last summer. Everybody likes his Oriental with the Magnum, including PW. Steve

>Everybody likes his Oriental with the Magnum, including PW.
> Steve
>

Indeed. However, it is worth noting that the particular combination Mike used in Salem, Oregon, at the Fall Follies, had a good bit of the speed knocked off. All the Good Stuff was still there, lots of power, real good speed regulation, it just didn't roar around to the level it has in the past.

I was quite envious...

We use a ~.255 venturi (it fits the OS 32F) and a .155 NVA.
And 11-4 Bolly 2B, or 10 1/2 -4 3B.
The MAgnum is a great, low priced, stunt engine. Just don't try to run it in a 4-2.
Bill <><

>We use a ~.255 venturi (it fits the OS 32F) and a .155 NVA.
>And 11-4 Bolly 2B, or 10 1/2 -4 3B.
>The MAgnum is a great, low priced, stunt engine. Just don't
>try to run it in a 4-2.
>Bill <><
>
>When the character of a man is not clear to you, look at his
>friends.
>Japanese Proverb

True enough; they just don't like a 4-2, much like another engine I could cite. And won't.

However, just as with this unmentioned engine, start applying old-school tuning techniques and you'll also end up throwing away the basic goodness of a Magnum 36. Just as well start with the Real Deal--a nice Fox 35--if that's the sort of run you want.

It may--or may not--be worth mentioning that I machined a simple sleeve for the venturi on my Magnum 36 and installed it with J-B Weld. Lots easier to use the whole slew of O.S. and O.S.-sized venturis I've got laying around than making a bunch of new ones.

Incidentally, I think PTG told me venturis from the O.S. 46FSR are a drop-in fit, and that he hit up a friend who had piles of the things laying around unused.