I have an older OS 80 2S, Double plug engine.

 Anyone ever use this engine? I'm thinking this OS 80 instead of an OS 90 4S, that I have.

CB

Seriously, I would want to weigh that lump before considering using it in a stunt model and I am taking a wild guess here that it could be 30oz +?
(And its not a four stroke either, but anyway. )

Seriously, I would want to weigh that lump before considering using it in a stunt model and I am taking a wild guess here that it could be 30oz +?
(And its not a four stroke either, but anyway. )

The .60 version of these OS rear drum engines weighs 15 oz.   I doubt the .80 would be much over 20 oz if tht much.  Again, these engines were used by the RC people for scale models.  They can carry a big prop and they run fairly smooth.

Maybe CB can enlighten us as to what his .80 does weigh.

Keith

You will be suprised at how anemic those 80's were.
Dennis

The .60 version of these OS rear drum engines weighs 15 oz.   I doubt the .80 would be much over 20 oz if tht much.  Again, these engines were used by the RC people for scale models.  They can carry a big prop and they run fairly smooth.

Maybe CB can enlighten us as to what his .80 does weigh.

Keith

Hi Keith,
              just looking at the OS Max web site concerning discontinued engines and it gives most of the older 60H motors as being over 20oz without muffler, sooo add the muffler and the extra beef for the bigger capacity and that's where my wild guess came from.

But If Charles says it weighs in at 18.3 then that's what it is but consider that the OS 80H is then lighter than a the LA 65 at 18.9oz and on par with the 61 FP and I find that odd when considering  double ball races on the crank, needle rollers on the rod and the rear intake setup.

Thanks.

P.S. There is a little control line info here -
http://www.rcgroups.com/forums/showthread.php?t=1185062

Hi Keith,
              just looking at the OS Max web site concerning discontinued engines and it gives most of the older 60H motors as being over 20oz without muffler, sooo add the muffler and the extra beef for the bigger capacity and that's where my wild guess came from.

But If Charles says it weighs in at 18.3 then that's what it is but consider that the OS 80H is then lighter than a the LA 65 at 18.9oz and on par with the 61 FP and I find that odd when considering  double ball races on the crank, needle rollers on the rod and the rear intake setup.

Thanks.

Well, the Peter Chinn articles on the OS 60H (rear drum) published in Model Airplane News (Jul 67 and Dec 69) lists the the OS 60 rear drum se at 14.9 oz.  I have four of these within a few tenths of an oz from the Peter Chinn published numbers except the one that has no exhaust restricter (coupled with the throttle) comes in at 14.4 oz.  These engines ran smooth and have a very effective throttle.  They carried a big prop on a heavy CL scale plane and had all the power that I needed.  Very dependable.  I would not hesitate using them on any suitable sized scale model for CL.   Hand starting was no problem with a cold engine and after it was broken in would start easily when warm.

I am not sure, but I would suspect that the front intake 60 versions of these engines weighed more than the rear drum versions.

I have no experience with the 80 version, but do know that it was used in the RC scale arena in its time.  No, these engines do not have the power of more modern similar sized schnuerle engines, but for scale operations, they worked just fine.

I would be interested on what Dennis Lipsett based his "anemic" comment.

Keith

As I mentioned in my last post, I think those OS rear drum engines were lighter than their front rotor counterparts because the crankshat was significantly lighter.  It was not as long and probably smaller in diameter because it did not have to have the intake passage machined into it.  This also probably results in smaller diameter bearings and a comparitively smaller front shaft housing.  My thoughts based primarily on observation.

All in all, they were nice engines for thier time.

Keith

You will be suprised at how anemic those 80's were.
Dennis

Having used that engine when it was a currently produced product i can reasonably assume that even then there was a decded difference of opinion on what constituted a powerful engine. Granted the engine could handle a 14 inch prop but so could a Fox 78 and a ST 71 and I assure you that the OS was not the leader of the pack.
Dennis

That Martin Baker looks great!

Static prop or working prop?

Other specs please?

Really nice model. Kudos.

CB

The Martin Baker MB 5 is 1/10 scale (42 inch span, about 45 inches long).  Powered by the OS 60 H rear drum version.  For static display, the counter-rotating prop was functional.  For flying, it used a conventional two-blade prop/spinner.  Non-retracting gear.  Main gear and tail wheel are shock absorbing.  Full swiveling tailwheel.  Operating flaps.  Controls in the cockpit operated the elevators, rudder and ailerrons.  For flight, the rudder and ailerons were hooked up to the throttle so for high speed, there was neutral rudder and ailerons, for low speed, it had right rudder and right ailerons.  Sliding canopy.  Running lights on wing tips and rudder could be turned on and off from the handle.  In flight operating shutter on the bottom air scoop.  5 lines.  Weighed just over 60 oz.

Placed in Precision Scale at the Nats - 3rd in 79, 2nd 96, and 1st in 2000.  Received highest static scores in each of these three Nats.

Thanks for asking.

Keith

The model is currently in the AMA museum in Muncie.