Performance of OS .65LA for control line?

Does anyone have any experience with the OS .65LA when used for control line? The smaller versions seem to be fairly popular for stunt. Does the .65 have similar characteristics? How does it compare with other .60 size engines, in particular the ST .60?

Dave Hull
LA_Flyer

Well,
On the bench they run pretty well with good power and excellent controllability.
I've never put one in an airplane because they weigh more than most of the big 4 strokes. They must make the crankshaft out of lead (only kidding).

Seriously I can't imagine anyone trying to use one as a serious stunt motor because of the weight, even if they do run good.

Thinking about that however I'm sure someone has tried it!

>Does anyone have any experience with the OS .65LA when used
>for control line? The smaller versions seem to be fairly
>popular for stunt. Does the .65 have similar characteristics?
>How does it compare with other .60 size engines, in particular
>the ST .60?
>
>Dave Hull
>LA_Flyer

This has been covered several times previously. It should run fine, but at 18 ounces it is a door stop. When you can get good 60 size engines at around 12 ounces, that 18 ounces has scared most people
off.

Oops, edit. The thing weighs 19 ounces.

Thanks, guys. The plane I have in mind has an unusually short nose and a ton of drag. It will need to swing a large diameter prop because of the cowling. Is an OS still in the running?

Dave Hull
LA_Flyer

When there's a ton of other engines with as much power and 5-9 oz lighter, it doesn't seem a good bet.

>When there's a ton of other engines with as much power and
>5-9 oz lighter, it doesn't seem a good bet.
I don't know Randy,
Get a short nosed biplane and you just might want that boat anchor in it to keep you from adding a ton of lead.
That is the reason you see such big gassers in relatively small ARF R/C. They need the weight and some of the owners actually believe that that makes them faste
Dennis

It just amazes me how some stunt people just automatically turn their nose up on any motor heavier that a st60. Reasonably priced motors such as the K&B 60 or the early Fox eagle that can run very well have been disrespected because they weigh a couple of ounces more than a St 60.
That being said, the current crop of potentially usable mass produced 60-90 motors are about six ounces heavier and quite a bit larger than what we are using. They will almost require a new airframe to be built for them. Some of the newer arf airplanes might make a good test bed for someone to do some testing with. My Score is still a tad tail heavy with a ROJETT 65, tru-turn spinner and an ounce spinner weight. Not really that much tail heavy for my taste, but it could fly quite well with a heavy motor on front. After I retrieve that motor for the contest season the score might become a test bed for some modern mass produced 60- 90 motors. Another model that might be good test bed is the new Strega ARF or ARC. It is a big plane. A K&B 60 fits into the Strega nose without any problem. A OS 65 la or ST-G75 or G90 will fit with a little bit of shaving on the outside of the motor lugs and about 3/32 taken of each of the motor mounts.
For competition purposes, the ROJett and PA series of motors can’t really be beat, but there are quite a few people who can’t or don’t want to put 500 to 600 dollars in the front of their airplane. (Motor, pipe, header, spinner, prop, shipping, taxes, ect.) It might be a fun project to spend some time figuring out what can be done to make modern mass produced 60 to 90 two strokes motors run reasonably well

Dont know this engine at all as far as suitability however- I have used Merco 60's(I believe 16 oz) and have seen K&B .60's used with good results. At least one competive flyer has used Fox .60's also with good results. Its a matter of trim. Still one wonders why go through the process when other 60's are available. The OS .65 is not a cheap motor. Other stunt dedicated motors could be had for around the same amount. If you like to play, go ahead with the OS and just design and trim around the extra weight.
Jon Ramsden
<@_@>

>Still one wonders why go through the process when other 60's
>are available. The OS .65 is not a cheap motor.>

Watch Ebay. I got a new os65 la for under $40.00. Best deal I ever got on Ebay. Were you thinking of the OS 65 vr motor? that would be a diffrent story.

Part of the fun of modelling is trying something diffrent. Just to use the same old stuff for years and years can get boring.

One of the best running motors around here (North Texas) is a 70s vintage Fox eagle 60 running on a metal pipe.

What other $110 (at Tower) 65 motors do you know of? Ones that could be modifued without much trouble- needlevalve, venturi, head gasket.

These heavier motors would be a good bet for something like a semi-scale F6f, F8F or P-47. The originals had big, heavy radial and short noses. A heavier motor would allow a shorter, more realistic fuse. The shorter fuse would offset most of the weight, since the fuse weighs around an ounce an inch.

>>Still one wonders why go through the process when other 60's are available.<<

Don't get me wrong. My point was just that there are a lot of other choices that aren't as heavy. If you have a big, heavy plane that requires a boat anchor in the front to balance, then find a heavy engine to put in there. I suspect that, as Len notes, the OS 65 probably would run fine. I just think there are other choices that seem to make more sense, at least to me. But whatever. Point here is to have some fun and trying different things is part of it.

I'm surprised no one has mentioned the OS 46ax or the new 55ax.With a venturie and nva,the 46 comes in at 12.25 oz. The 55 at12.75 oz.Both have same mounting dimensions as a 40vf,RO60,PA61. Intake and exaust timing very close to a 40vf. With a side to rear header and a pipe would it be possible to get the same kind of run as a 40vf or am I missing something here.
THANKS Dennis

What model are you talking about?

The 65La would be a choice if you are stuck in a budget, and in that case, as others have mentioned, the KB 60 would be an engine for you to take a look. If you call MECOA they will probably sell you an engine without the Carb and the Muffler, for even less money.

The other engine which I have never heard any one using, but it is at the same price and same weight of the OS 65LA is the Tower 75 w/ dual BB and a lot more power then the 65lA

Short Nose and Dragy ship sounds a good model for a Saito 72. 4Stroke engine burn less fuel, especially the OS 70 Ultimate, so on the long run you can save money going with a 4 Stroke.

On a local contest a couple weekends ago an OS FS-70 Ultimate turning a 14x6 prop pulled a P-51 for the whole pattern using only 2.2Oz of 20% nitro fuel.


Martin

Dave

I have been Running a LA65 on a SIG Fazer. It has been a blast. It flies well with a 13X6 Zinger. Plenty of power and easy to handle. They really like fuel, Make sure you have room for the tank or you will have to build one(guess how I know).

Get a hold of Russ Gifford he has venturi and needles. I did nothing intenal. If you leave the muffler off they sound like John Deeres.

Thanks, all of you!

I will try to do a paper "weight and balance" job. That may help decide the issue. Being able to run the 13" prop is important and so is the info that the .65LA behaves like the others. I really didn't want to start down the 4-stroke path. To much new stuff to learn right now.

More planning to follow....

Dave Hull
LA_Flyer

>Thanks, all of you!
>
>I will try to do a paper "weight and balance" job.
>That may help decide the issue. Being able to run the 13"
>prop is important and so is the info that the .65LA behaves
>like the others. I really didn't want to start down the
>4-stroke path. To much new stuff to learn right now.
>
>More planning to follow....
>
>Dave Hull
>LA_Flyer

Hi Dave,

Before you buy anything talk a lot with the experts. There is a lot more then just weight and balance... a lot more issues...this one is the easiest

Good luck on your project and one way or the other you will have fun!

Martin
ps. ah..don't forget to take into account the weight of the fuel you will burn.

>Dave
>
>I have been Running a LA65 on a SIG Fazer. It has been a
>blast. It flies well with a 13X6 Zinger. Plenty of power and
>easy to handle. They really like fuel, Make sure you have
>room for the tank or you will have to build one(guess how I
>know).
>
>Get a hold of Russ Gifford he has venturi and needles. I did
>nothing intenal. If you leave the muffler off they sound like
>John Deeres.


How much fuel do you burn?

I am just wondering, how heavy does your model takes off?

Martin

On the Sig Fazer It takes 7-8 ounces to fly 6-6.5 minutes.
These are rough estimates, I use a fill and draw off method. The tank iI built is about the size of a 10oz. plastic.
The Fazer has a bit-o-heft and a very thick wing. I will try to get a weight on it later tonight.

My Fazer weighs in at(drum roll) 68oz. dry.
Quick run down:
LA 65 no muffler
Homemade tank, .008 shimstock
Tail section hollowed and sheeted
NO R/C stuff
hope that helps, The LA and FP series are easy to handle.