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Author Topic: O.S. SF 46  (Read 865 times)

Offline Peter in Fairfax, VA

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O.S. SF 46
« on: May 05, 2019, 09:27:20 AM »
Just bought a new O.S. SF 46 ABC, the control line version, new in box. 

Got a suggestion to run a Bolly three blade prop.  However, I was thinking a 12-6 Rev-Up.

Any thoughts on how to handle this engine, in terms of break-in, fuel, props, the quality of the stock NVA, the supplied venturis, etc?  My break-in plan was bolt on a 10-6, run it rich on 5% nitro and run out three tanks, with a brief 30 second first run.

thanks,

Peter

Online Brett Buck

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Re: O.S. SF 46
« Reply #1 on: May 05, 2019, 10:16:25 AM »
Just bought a new O.S. SF 46 ABC, the control line version, new in box. 

Got a suggestion to run a Bolly three blade prop.  However, I was thinking a 12-6 Rev-Up

   I would suggest a more conventional stunt prop,11.5-4 3-blade or 12-4. Common commercial props, I would say an APC 12.25-3.75. Based on what I have seen and assisted with, if you want to run it on a 6" pitch prop, send it to Randy and get it modified to do that.

    Brett

Offline Carl Cisneros

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Re: O.S. SF 46
« Reply #2 on: May 05, 2019, 11:55:04 AM »
Peter;

do NOT run the ABC motor RICH..... (4-stroking)

They need HEAT to run correctly.

start out with a nice rich'ish 2 stroking.

run it in short runs and let it cool off completely and run it again the same way.

The prop that Brett recommended is a very good prop (APC one) or a XOAR 12-4 also.

Also, what is the oil percentage of your 5% fuel?

Carl
Carl R Cisneros, Dist IV
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Offline Peter in Fairfax, VA

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Re: O.S. SF 46
« Reply #3 on: May 05, 2019, 03:35:35 PM »
Sorry for an earlier typo.  I meant a Rev-Up 12-5 cut to down to 11.5, which is my favorite LA 46 prop.

I've just ordered an APC 12.25x3.75, as many folks here say that is a good LA 46 prop.

Offline Peter in Fairfax, VA

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Re: O.S. SF 46
« Reply #4 on: May 05, 2019, 03:36:16 PM »
I'd run Fox Superfuel (29% castor) for break-in.

Offline Carl Cisneros

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Re: O.S. SF 46
« Reply #5 on: May 05, 2019, 03:41:42 PM »
not on an ABC motor
Carl R Cisneros, Dist IV
Control Line RB

Online Brett Buck

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Re: O.S. SF 46
« Reply #6 on: May 05, 2019, 03:46:03 PM »
I'd run Fox Superfuel (29% castor) for break-in.

   Please don't! That much oil is neither necessary nor desirable. At most, 22% 50/50 castor/synthetic, but 18% 25/75 would be OK, too. All that running 29% oil will do is varnish up the piston and cylinder in very short order.

    A 12-5 is also far too much pitch, unless modified to reduce the power.  The engine is substantially more powerful than a 46LA. The best runs anyone got, locally, was with typical 46VF props. I am not sure what sort of airplane you are imagining, but I would think typical 40-60 tuned pipe airplanes.

       Brett

Offline Peter in Fairfax, VA

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Re: O.S. SF 46
« Reply #7 on: May 05, 2019, 04:25:08 PM »
The plane is one that was built by another NVCL member, Scott Richlen.  It's a Silver Lancer.  It has no pipe.

I do expect the SF 46 to be more powerful than the LA 46.

I'll run 50/50 castor/synthetic at 23% oil, 10% nitro.

> Best runs were with typical 46VF props.

What is a typical 46VF prop?

 

Online Brett Buck

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Re: O.S. SF 46
« Reply #8 on: May 05, 2019, 05:01:15 PM »

> Best runs were with typical 46VF props.

What is a typical 46VF prop?

 

   As noted above, 12-4 (or less) 2-blade Bollys, 11.5-3.75 3-blade Eather "flat-back", that sort of thing. The closest commercial prop - originally designed to be used on piped 46VFs - is the APC 12.25-3.75.


    Brett

Offline Matt Spencer

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Re: O.S. SF 46
« Reply #9 on: May 05, 2019, 08:29:40 PM »
Running a 46 SF clone , in a 60 Oz magnumish thing , found the 5 in pitch wasworking . 4 to fine & 6 to much .
Though only 1/2 Dozen flights total  :-\ ( this is why FLIGHT LOGS are usefull .  :-X ) .   A Royal 46 .
Theyre fairly coservatively timed , 120 Trans 140 Ex . I think 45 closing - on the shaft .( same as the OS . )

Looking at the OS parts listing , I think the C L is just the intake etc . ( Not another shaft like the FSR 40 .)

Was better without a extra head gasket .

With further use , it might ' cam up ' nicely on the 4 in pitch . Maybe ' Hemi ' ing the head would sort it out .
Think I had the extra gasket in it earlier , on the 12 x 4 3 blade , . wasnt ' up in the rev band ' for that then
flying in rough air . after a 12 x 6 Bolly . So threw on a 11 x 5 master  and it steadyed up .

Was trying to run it ' at the break ' . Was one in there somewhere , but couldnt get it consistant . with minimum effort .
But seemed willing . If I had a spare head , Id try the full Hemi - 1/16 squish band trip .

The Mounts pretty much the same as the G - 51 , so fits a multitude of Std mounts . Was in the Field Box to try in the 5 Tonne Strega
after the G 51 last Saturday , but didnt get arount to it .

BIGGEST ANNOYANCE was ' ' drying off ' in hard turns , with a .310 intake .
A bit gutless on the .275 , so has a .295 in it , for The Next Tryout .

ALSO , the Std. muffler it was a good bit rich inverted , tank level with spraybar . Swapping to a Tounge got it dead even straight off .

Similar internals to a T Tiger Pro 46 ( some parts will swap ) with lower timing so better if looking for a 4-2 run , we should hope .
Seem to be quite a few people have used them succesfully over the years - if you put OS SF 46 in Search .

On the Bench , DONT run it slobbering rich . Short Bursts ' at the break ' heat it quicker . Theyre Tight Cold , so NOT 4 Stroking .
The Olde ' pinch the fuel tube ' trick , snaps it up & down , in revs .
Seems the ' Heat Cycle ' is the trick on ABC break in . Get it Hot , Stop , FULLY COOL before next start .
After the first hours running maybe 18 % oil is best .
If the weathers real hot I use 3 % Castor in Synthetic oil fuel .

If youve any nice ' stunt ' tube mufflers , likely theyed work well , if its power you need . ( the Strega is 75 ( Er 6 actually ) Ounces .
So I might need it more go-go than youd need .  :-X LL~ )

HoKay , here are the timing figures .140-114-108 . So wondering if blocked boost or vertical  : 1/8 port divider'd pay divideds .

Blowdowns a bit more than ' we like ' . Cranks 35 - 45 BUT Royal Magnum etc etc , Do tend to set crank timing at variance with the OS .
Usually narrower . Royal being the conservative . Closing earliest .  :P Theres a ton of ' Clones ' as the boost has a place for a sticker .

Nailed the engine in the Strega last night. Anyway .
With Bretts advice Im tempted to try the 12 x 4 Glass Prop . Set it the Nose vertical 2 / 3 ' clicks ' rich & shake it - trip .
Was producing the same thrust as the G -51 on a 10 x 6 3 blade tornado . 76 ounces .  :( ( G-51 more or less flys it )
Thinking now itll be a 2-2-2 set up . Will chime in if it works .Drag the G 45 down there to I think . Same Prop .

Not trying to highjack the thread or anything . Just thought I may as well chime in .

Almost had the tank out in the wee small hours . Was cursing the FSRs for ( usually ) speding up as it emptied . After It Did It with the G-51
going to have to inspect the pipework . Commercial Tank . SO one has to sort of double check / cross referance ' a few problems '
If it dosnt hit of right , straight of .

I saw something last night , refering to the SF as likeing being RESTRICTED in the EXHAUST , to ' govern ' them . Nota 1/2 in outlet .
As in a toungue or a restricted outlet hole tube muffler . If they work as well as a FSR 25 theyed be darn good .
My FSR runs slobbering rich , side mounted. tank inboard of NVA . Superp pull as she rises , back in slobbery level . Moderated even .

Heres the G 51 alongside the Royal 56 OS FS 46 CLONE . maybe the props 1/2 mm further forward , and the needle 1 mm back or forward .
Ex Ports a sixteenth closer to the bearers . differant hole required in the cowl around the head etc . 4 x bolt pattern identical .

Whats 76 ounces between friends .  ??? :( We will see  ! .
« Last Edit: May 08, 2019, 10:28:10 PM by Matt Spencer »

Offline frank mccune

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Re: O.S. SF 46
« Reply #10 on: May 27, 2019, 09:19:02 AM »
       Hello Peter:

       I hope that the OS SF .46 is a good engine as I have two in my "junk drawer" waiting to go into a Score airplane.


                                                                                                                                                      Good luck,

                                                                                                                                                      Frank McCune

Offline proparc

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Re: O.S. SF 46
« Reply #11 on: June 12, 2019, 04:07:50 PM »
That O.S. SF 46 is a sweet sweet motor,( I have 2 SF 61's ). Especially if it is the rare,(and overpriced ring version). I have VERY STRONG opinions about fuel for that motor so, I won't share them but, look into the OS #6 hot plug for quick hand starts and consistent running, (of course, dependent on where you are in the galaxy etc).

Almost got an NIB ringed version but, I decided that they are just too nice to fly. :-\ :-\
Milton "Proparc" Graham

Offline Matt Spencer

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Re: O.S. SF 46
« Reply #12 on: June 20, 2019, 08:19:26 PM »
Finally , just flown it ( again ) this time , with 8.8 mm bore Enya Venturie & Fox 15 muffler
 (  , std thingo removed , set square to 1 inch
stack , opening  sized tho match engine )



As in whack off that stack , bolt holes through center of diameter so equispaced ea side. Tangental even . Not offset like that .

in the Strega . 12 x 6 master wood prop . Dead Stock Royal 46 LS / OS  FS clone ( abc ) ( bar cross drilled case for spraybar . OS already is )

good 4-2 run , seems stable , plenty of grunt ( used muffler pressure ) 9/9/ 10 N  fuel . not at all loud in comparison to most you hear ,
or at least a wofflier softer note , maybe as the mufflers got a slotted tube baffle .

Early days yet , but better by far than the 275 & 295 & .312  intakes . 8.8 is .346 . But I measuered .351 back home, as used .
Did a % displacement calc. from the FSR 25 clone with the 7.5 intake , got 9 mm bore with 4 mm spraybar as a equivalent ,
So theres a thing .

Devoured 6 Oz. / 150 cc for the pattern .
« Last Edit: June 21, 2019, 07:11:21 AM by Matt Spencer »


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