Engine for a SIG Magnum

Hello All,
My name is Richard Walbridge from Fresno, CA and I have a question regarding a motor/setup for a SIG Magnum. I have been researching 4 motors/setup types for my new ship. The Magnum will be my first 'full size' plane. The kit was given to me sometime ago and my flying and building abilities have just caught up to the skill level of the kit. I have viewed Walter Umland's Magnum photos with a Double Star .61 LT and liked what I saw. By the way Walt, that ship looks great!! I have also considered a RO Jett F.I.R.E. .61 BSE stunt motor (which just makes the hair on my neck stand up!), a good all around Super Tigre .60 (light case, early model if I'm correct) and a Saito .56. I have zero experience with 4 stroke motors so that one is a good as gone. I have heard that Double Star Engines are a waist of time and money and the RO Jett costs more than a new Mercedes (in terms of CL motors ). My first choice is a Super Tigre .60. I realize that one probably gets what one pays for in terms of guality of motors but I would like to hear some good criticism from you guys and your combination/setups before I begin this kit. Dirty Dan? PW? Bruce Hunt? Thanks!

Olive you keep
on flyn'

>Hello All,
>My name is Richard Walbridge from Fresno, CA and I have a
>question regarding a motor/setup for a SIG Magnum. I have
>been researching 4 motors/setup types for my new ship. The
>Magnum will be my first 'full size' plane. The kit was
>given to me sometime ago and my flying and building
>abilities have just caught up to the skill level of the kit.
> I have viewed Walter Umland's Magnum photos with a Double
>Star .61 LT and liked what I saw. By the way Walt, that
>ship looks great!! I have also considered a RO Jett
>F.I.R.E. .61 BSE stunt motor (which just makes the hair on
>my neck stand up!), a good all around Super Tigre .60 (light
>case, early model if I'm correct) and a Saito .56. I have
>zero experience with 4 stroke motors so that one is a good
>as gone. I have heard that Double Star Engines are a waist
>of time and money and the RO Jett costs more than a new
>Mercedes (in terms of CL motors ). My first choice is a
>Super Tigre .60. I realize that one probably gets what one
>pays for in terms of guality of motors but I would like to
>hear some good criticism from you guys and your
>combination/setups before I begin this kit. Dirty Dan? PW?
>Bruce Hunt? Thanks!

first let me say thanks

this plane is not for me personally so I dont take any offense about the double star being a waste. however I do think in the 60 size engines the D.S. is a good midrange priced engine but given the other choices you have listed I would say buy the mercedes if you can(not to emply you can't) I here they are really great! I bought one not to long ago.
now if you can get an ST 60 that would be my second first choice(after mods your probably going to be close to the mercedes anyway) if that makes sense
either way plan ahead and make your mods to the kit because you will need to widen the fuse to fit the larger engines in

now if you really want a nice match for the Magnum and don't want to do the 60 scene I know first hand that an OS 46 SF will meet the magnum's needs and I have a few of them in the vault. (LOL ! )

I just finished my Magnum, and I have a ST 51 in it. Had its first flights this last weekend and I couldnt be happier with the motor. It pulls like a truck, will do the entire pattern in 4 cycle. It has a nice break and starts on the first flip. A bolly 12 in 3 blade works real well. Mine is worked from Tom Lay, however I have heard similar good news about box stock motors. They are avaialble at Tower for just over a hundred bucks.
Other options- Len's ASP 53 has a real good reputation. I would give it strong consideration. At $150 you get a reworked motor dedicated to stunt. Light and powerful.
Finally you could look at the Modusa motors. They look real nice are reasonably priced and said to be powerful.

You really do not need a 60 size motor for the magnum. The 50 size motors have plenty of power and are lighter and cheaper.
Good luck,
Brian

Rich,

The Martini Kid, so that's what you're into now that you've moved to California. Does that mean you drink martinis every day after work or that you got Stephanie drunk and pregnant? Either way, congratulations!

Now about that engine choice. You can usually score a good ST60 from Tom Lay (a fellow Californian). Or buy one from me. I'll let one of mine go for $150 just for you. I ran all of my inventory of ST60's in a run off this summer and scored them by ease of starting, needle ability, and apparent power (very subjective). One of Tom Lay's reworked ST60's with a tapped muffler adaptor has your name on it.

If you can build it light another good choice would be the ST 46 if you can find that doesn't cost like a mercedes. Mike Gretz used one on the prototype if I am not mistaken, he also flew it with an early 45 size four stroke which doesn't produce near as much power as the current crop does. The bar stock RO-JETT 61 or 65 is available with a muffler that can be hidden inside the fuselage and is a sweet engine. I've watched Richard Oliver put up flight after flight as fast as he can land, refuel, and launch with no problems from the engine(piped).

I would vote for the ST G-51 C/L. I have been running the 51 for four years and its a great motor. Gobs of power with very little rework. An extra head gasket and maybe a venturi mod and you are up and running. I use Powermaster 5% GMA blend (22%) oil. Bolly 12x5 prop. Total weight on my Magnum is 62 ozs.
Wayne

I agree with Wayne and Brian - one of the fellows here in the Northeast flys an ST .51 powered Magnum and it's one of the best fast 4C runs I've ever heard. He's an oustanding pilot and the plane/engine combination really works well.
Bob Z

"Mike Gretz used one on the prototype if I am not mistaken, he also flew it with an early 45 size four stroke which doesn't produce near as much power as the current crop does. "

If I'm not mistaken, and at the risk of offending Mike Gretz, wasn't the Magnum a project and design by Mike Pratt? Sometimes it's difficult to keep all those SIG "Mikes" straight.

Martini Kid (nice handle),

Well there are a number of engines that work very well in the Magnum, but it all depends on how much money you want to spend. My suggestion for you would be the St .51 reworked by Tom Lay. This is a killer set up at a lower price and is very consistent. Just set it and go operation. There is nothing wrong with the RO Jet engines, PA .61, or the St .60 but the bang for the buck goes to the ST .51.

I flew the all the prototypes with engines ranging from the stock ST.46 to the Saito 45 Special and they all worked well. The best set up for me was a hotrod St .46 that put out the same power as the ST 51. I also helped a good friend (Sam Sciorrotta) with his Magnum that was equipped the T&L ST.51 and was really impressed with the power.

Mike Pratt (not Gretz)

Got to go with Mikey and the others who suggest the ST G51, especially the Tom Lay rework. Got the same set up, works great.

Bill <><

Mike

Sorry about getting the last name wrong.

Now that we are on the subject of engines an the Magnum.
What is your fellows experience with the Merco 49 (reworked)
Do you like it or what?
Dave.

I had one in the blue box top magnum and it never really ran that well for me. But that doesn't mean it was a bad engine, just not the one I had. I would think that the LA .46 would be just as good for less money and should work in a light Magnum.

Mikey

Tnks, Mike for coming back on this question. OK, I have this Merco 49 NIB -"Black Hawk series" and has been reworked by Tom Dixon. It weights l4oz w/ tongue muffler (yea, heavy I know) Is this too heavy for the Magnum? I bought this back in 1985 (Boy time slips away!!! Like we are in fast forward after we retire) Is this a case of other engines were being used and this one did not get a fair chance. People seem to gravitate toward the "Popular" engines being used at the time and place. Maybe here in the NW it was not used that much--What about you people in other parts of the country- What is your reaction?

LAST EDITED ON Nov-11-03 AT 10:52 PM (CST)
 

Dave, the issue with the Merco .49 is that it's the same size and weight as the .61. Dave Royer is the one to talk to. He's a Merco fan.

Martini, I love my Double Star .60bb, enough to write the essay in the Product Report forum. No hint of low power output, in fact, it has been both powerful and docile. Really delightful.

I think the problem is that the best engines are setup with more pinch at the top of the ABC/AAC...RO-Jett, PA, Saito, Stalker and 2Star. The Russian engines also have very high silicon content in the aluminum piston, and the chrome is extra dense. All this means that these engines need more break-in (1-3 hours), and folks are used to the OS ABN engines that are set up to be idiot proof, little taper, very loose. It sounds like you have several good engine suggestions. Steve

Don't remember the 49 being a big seller for Tom. The 61 weighs less and puts out more power.

OK, I'm getting the drift. guess I have a boat anchor!!!
Nice engine for something---uhhh, Put it in a Showteam, fun airplane. Thats the fun of the "Firecats" showteam, build a plane that you can't really compete with but has ALOT of nostalgia. Speaking of which--Anybody see the plane that was built and flown by Allyn M Aldrich--called "THE VETO" Article was in MAN June 1955. INTERESTING--It takes off and lands on its tail. With electronic control on a throttle, Hey its SHOWTIME with the Firecats and have FUN.
Dave

Dave,

The Dixon Merco .49 will work just fine for the Magnum. I used one in my Super Chief for 4 seasons without any problem. They'll swing a 13 inch prop and have enough beans to haul up to a 70 ounce ship. If you don't have a .61, use the .49 and enjoy. Give me a call sometime and I'll share my "secrets" for making the .49 happy - it's all in the plug(s) and fuel.

My suggestion for you would be the St .51 reworked
>by Tom Lay.

I agree.

Cut off 1" of nose and go with the Saito 56, but I understand your hesitation. 4 cycles make for a lot of practice, but it is noce to have a few around to copy...

Let me throw one more thing into this discussion (just to confuse everyone a little more LOL). There are a bunch of engines that are available that would do a great job in Magnum or any other model about the same size. Many more than were around when that model was first designed, that's for sure. Whatever engine you use the biggest thing to remember is to make sure that you set it up properly and use the best accessories that you can put on it or have it reworked by someone that knows what they are doing. If you are not an expert save yourself the time and frustration of having it reworked so you can concentrate on flying the pattern and not worrying about the engine run.

For this reason too many people jump onto the pipe setups and don't take the time to learn how to adjust them and/or set the pitch on the props. Both take a little learning and the up and coming flyer doesn't need the hassle until they can use the extra performance form these set ups. He would be better off concentrating on properly trimming his model. Everyone has their own personal preference to what engines they like best but remember they can all be make to run very well (OK so a few will be a little better).

Mikey,

I just acquired a Sig Magnum new in unopened box for a great price. This should be a good project for next winter (as I am in a two plane building mode for the NATS right now). I have an LA46 which promises to be pretty strong. Should I look for another motor. I also have a new PA40 pipe motor now breaking in for a Buso Vegas now on the board. Are both these motors a little weak for the Magnum? Also would you suggest a partial foam core and built up wing to reduce weight? Other suggestions for construction would be appreciated.

Mickey, The Primary Force is still flying great and picking up hardware. You created a fine flying profile in that kit.

Bob Smiley
A Lancair 360 builder/flyer trying to be a modeler.

Hi bob; In my experience, the L.A.46 isnt enough for the Magnum,mine is perfect for the humongous which only weighs about 35 oz. but the P.A. 40 on a pipe will pull it real nice. Think of Gerry Eichten and Chris Cox with their O.S. 40s on good size ships.And Bruce Perry when he used a P.A. 40 on a full sizes ship. The difference is the pipe.Keith V.

Keith Varley

Thanks Keith, I thought the piped motor would do it. The Vegas is a little smaller but I was thinking the PA40 pipe would go in that plane.

Are you freezing yet in Canada with this weather?

Bob
A Lancair 360 buldier/pilot trying to be a modeler

Bob,
Good to hear from you! The PA 40 with the pipe is a great combo for the Magnum, lots of power. Run the Bolly two blade 11.5" x 4" with the pipe length set at 18" to 18-1/2" from the first baffel in the pipe to glow plug.

Having said that, I am impressed with the LA.46 mainly for its reasonable power out-put, light weight, and low price. If you want to use the LA.46 then the Magnum will have to weigh in the low fifties, which is not hard to do if you keep the paint down to a minimum and use contest wood for sheeting the wing & stab.

Glad you like the P Force keep flying it and they will all wonder what is making you so good LOL.

Mikey

When I was preparing an old Magnum for the Video flights, I Went through my engines to see what might fit. I am not sure if this was a stock Magnum but the only thing I had that might be squeezed between the doublers was a Stalker .61 Side Exhaust. Even then I ended up chucking it in the mill and knocking about .060 off each engine lug. I don't remember what the Magnum weighed but I think it was over 60 ounces with the airborne video pack.

I had never ran a Stalker so wasn't sure what to expect. I broke the engine in on my test stand and put it in the Magnum. I added a head shim, bolted on a 13 X 5.25 3 blade CF prop and ran 5-22 GMA PowerMaster fuel. I really didn't know what to expect as I had seen several negative comments about the Stalker on this board but it sure acted great on the test stand. The only problem I had was it liked to start backwards and seemed to run backwards almost as well as it ran forward.

At the field, I fell in love with this engine, one flip starts almost every time (it always started but sometimes the wrong direction) The first flight I had the needle set a tad rich and the airplane was doing 6 second laps on 64 foot lines in 10-12 mph wind. I flew the entire stunt pattern on that first flight and never once felt like I didn't have enough power. It just growled through the pattern and impressed everyone watching. The next flight I turned it up a tad and was running 5.5 second laps. I couldn't have asked for a better non-pipe engine run.

I was really impressed so don't discount the Stalkers when you are making your final decision.

Richard,

Sorry. Evidently blew by your posting for a couple weeks.

While I believe my Impact was weapon of choice when we met, my Mutant Magnum--a Dixon re-design of SIG Magnum--was fitted with an ST 51 and I found it to be a very good combination. Steve Helmick now has that model/engine combination and I believe he is still happy with it.

My Impact initially had a CL version of the ST 51. Stock timing, added an extra (stock) head shim, fiddled with venturi size until settling on .273 or so. I thought it was a real good package. Good enough that I just had to screw it up by installing a Pond Scum motor.

Do be certain to seal the hinge lines on your new model. If Heavy Stunt and I have to drive all the way down there to do so, as happened in Salem, we're gonna be real upset.

My Suggestion
Read the picture book thst comes with the kit 50 times.
Follow it to the letter (no exceptions) and you will have a good plane.
It must be on the 62-64 .oz weight to fly well,
No matter what you put in it' It wont fly well at 70+ .oz
A st60,51or Merco 60 with gutted muffler works well
I had two; one with a Merco 60 ; one with a Tom lay st60(come to think of it still have em) the one with stock merco & chip
muffler flew better.why ? because it was lighter.
The tom lay SR60 ran very very well, but the extra weight of the plane kept it from realizing it,s potential.
This is very important to your success!
Don't regard it lightly.
Read the book! Its very good.