OS 52 4s working good...

Today, Oct 11, Brad and I messed aorund with the OS 52. Here is what we found.

UHP Manifold
#6 Venturi
YS 20/20 Fuel.

The day started out on 13" 3 blades. Very overloaded and really fell apart in the maneuvers.

Tried Eather 12" 4 blader still very overloaded.

Cut down a Bolly 13" to 12.5" and the pitch is 3.8. Take off RPM was around 10600, yep 10600. This was OK but could be better.

I had damaged a 13" Eather Blue 3 blade. I cleaned it up and the dia is 11 7/8". Pitch is 3.75. With this on there at peak RPM is 10,800. The flight was great but a bit lean in the maneuvers at the end of the pattern. Next I set it at 2 clicks rich. Take off rpm is 10,700 at two clicks rich. It was great. I flew it three times in a row without touching the needle. I loved it. It was really making alot of power. One thing I noticed with the high rpm it was much more steady in flight speeds. By that I mean the maneuver speed is much more close in relation to the level lap speed. It didnt want to do the over the top thing like many setups of before. I have tried it on a higher pitch setup running it more down in the torque curve area, 8800, and it really turned on and off and it was off the most in the verticles and overheads. I think I will persue this higher rpm run further.

I am sure Brad has some things he noticed today on his setup also. I will let him tell you about it.

>I am sure Brad has some things he noticed today on his setup
>also. I will let him tell you about it.

Mostly that it works really good.

Doug and I starting to get the "pipe like runs". The nose goes up and the airplane locks into one speed.

It seems the low pitch is not bad thing.

I was running my Saito 72 at 11,200 RPM with the Eather 4 blade 4 pitch. Extremely steady, like a sewing machine run.

The OS 25 Surpass is very cool. Excellent for the 650 sq incher under 60 oz. Very smooth and predictable.

As always, we will continue to fiddle, and report back.

Hi Brad,
Am interested in the OS 25 Surpass. Fuel, prop, tank set up, etc.
No 4 strokes, yet, but would like to know about this one!
TIA
Bill

I originally started with the O.S. 52, but shelved it after a couple of runs because it vibrated so much. I think it's lighter than the Saito, so it may prove to be a good choice.

How much break in did you do on yours? Does the vibration settle down?

Thanks.

>I originally started with the O.S. 52, but shelved it after
>a couple of runs because it vibrated so much. I think it's
>lighter than the Saito, so it may prove to be a good choice.
>
>How much break in did you do on yours? Does the vibration
>settle down?

Doug's OS 52 is very smooth for a 4 cycle. Smoother than a Saito.

The high RPM really smooths these suckers out too. My Saito 72 just loves 11,200 RPM!

Feel free to let us know what you would take for your OS 52, since it did not work for you! LOL!

I may not be free, but I am cheap.

I still have all the four strokes from my RC Pattern days. The 1.20s are too big, but why don't we try the .91 Surpass next. That was one of the nicest and smoothest engines O.S. made. Unless they changed the rules formula, it should be legal for CLPA and might be a great hauler in the 80 ounce range. Let's Pump you UP

Break in on my 52 was about an hour on the bench exactly like the manual says. Very different from Saito break in. It has some flights on it now and it just keeps running smoother and smoother as it come in. The shutoffs are getting better also. It runs best so far on YS 20/20 fuel NO castor. It wants to run rougher on a a castor blend fuel.

Mine is on a UHP manifold. It seems to run really good now in that config.

I dont know how it runs in an open carb config. I never tried it.

>>I am sure Brad has some things he noticed today on his setup
>>also. I will let him tell you about it.
>
>Mostly that it works really good.
>
>Doug and I starting to get the "pipe like runs". The nose
>goes up and the airplane locks into one speed.
>
>It seems the low pitch is not bad thing.
>

Hey, didn't I tell you that about a year and a half ago...

Brett,

I dont know what you told Brad but I know in the past when I treid the lower pitch props I would get horrible over revving in the corners and sometimes it would valve clatter really bad. So I would mave away from it. This was always with a carb on there and not really having a good way to set the needle. This was really my first try at the really low, under 4, pitch on a 4s without any real draw backs. Well maybe not. I have been on the apc 10X3 on the 26 for a long time. Brad has been successfully moving down in pitch for abot 6 weeks now and getting good results.

>>It seems the low pitch is not bad thing.
>>
>
> Hey, didn't I tell you that about a year and a half ago...
>
> Brett

Why, yes you did. A lot of things had to change between then and now. It is certainly not easy developing new stuff and trying to practice at the same time. Not to mention the fact that there are not a lot of guys to copy, as in the case of the piped engines.

I guess mostly what it took to get me moving in another direction was a good beatin'. Usually works to motivate. That and a slap from Gordon Delaney, who was defying my own logic and getting excellent results. Not to mention Frank Williams' testing and video tapes of Paul Walker.

Now I have a much more open mind. I also have had a lot of help and support from Brian Eather, who is eager to see the 4 cycle work also.

Anyone want to donate some "blue" Eather 13" three blades for testing???? Some "green"'s would be nice also. Just send 3.5, 3.75, and 4 pitch please, Doug and I will do the rest.

>>>It seems the low pitch is not bad thing.
>>>
>>
>> Hey, didn't I tell you that about a year and a half ago...
>>
>> Brett
>
>Why, yes you did.

After Ted told me about 20 years ago!!!

By the way, does UHP sell manifolds for OS's?

LAST EDITED ON Oct-14-03 AT 07:22 AM (CDT)
 
>
> By the way, does UHP sell manifolds for OS's?
>
> Brett

Yes, they do. The O.S .52 kit is listed at $65.00.

I don't know, 4 strokes should be pitch-friendly.(torque, and all) But my O.S. .40 never ran 'til I fitted it with a 12" Stir Stick from the Home Depot Paint Dep't!(balanced, of course) That's when I saw the R's go upstairs, boys. 13K plus! Wasn't poop in the turns, though...like ta never took off. Screamed, though...

>>>>It seems the low pitch is not bad thing.
> After Ted told me about 20 years ago!!!

This weekend was the best yet IMHO.

Eather 3.75 x 13 three blade at 10,700. Works well in the calm. Probably need a 3.5 or 3.4 for wind. I still think 11,000 RPM is better as far as a governed run.

I literally had the best engine run I have ever had in my life on the first flight.

This game is much easier with that governed run.

Man, this is getting fun.