ST46 Ears

[David Matthews]

Guys,

I should put this on the engine forum but I thought I'd get a quicker response and more reponses on the open forum.

Is there any internal differences between a ST46 with ears and one without? The reason I ask is I have a chance to buy one with no ears sight unseen and have to send an answer ASAP. I have rings, liners, heads, and cranks from the old days and only one good engine case with ears.

I've been away from the hobby since 1989 and was a member of the Queen City U-Control Club (Cincinnati), I now live in Townville, S.C. which is near Anderson/Greenville. I attended the Huntersville contest and was supplied directions etc. from Howard Shenton along with answers to some questions. Mack Henry and Phil Spillman went out of their way to answer some pretty dumb questions as I have been out of the hobby for some time. I plan on getting back into the hobby and had joined the AMA and PAMPA before going to Huntersville. Will Davis and Howard have me on some sort of email list to help me stay informed also, sorry for not helping out at the contest, Howard, but I was entertaining my wife at the contest also. Thanks all who took the time to answer my questions. After coming back from Huntersville I purchased an ARF profile Cardinal and plan to hang a ST46 on it. With the Cardinal and an old heavy unfrancherized twister with an OS 35 on it I plan on doing some flying soon. Going ARF goes against my grain because I like to build, but I will be in and out of town til the end of March. I have a few old combat planes to bang up also but no one to launch them.

I flew combat, speed and pattern. When I quit I was just getting the pattern in and won a few beginner contests and was flying intermediate. I guess I should start back in intermediate once I get some handle time in?

It seems my biggest hurdles will be finding someone to fly with reasonably close by and finding a place to fly. I seem to be able to find grass fields to fly from but paved surfaces big enough to fly from are rare when you live in the sticks. I've only flown from grass with combat planes as our club had paved circles in front of Lunken Airport. I believe the thing I liked most about flying controline was the people I flew with, I'll tell you I really missed the guys in Cincinnati but I had to quit due to my job and getting married and raising a family.

Thanks for the help,
Dave Matthews

[EddyR]

Dave Your question is like someone asking are all small block Chevy motors the same? Yes and NO The 40-46 were made both ways at the same time.Those motors are the same. Old double ring motors will not interchange parts with single ring motors. Also there are thin and thick sleeve motors. Most all double rings are thin sleeved but there is a cross over point where the thin sleeve motors had single rings. I have one and it is a good runner. Most of the eared motors have the smaller thrush washer bearing cover.  Old double ring motors has thin sleeves that warped when used with large props and many had no bearings in the con rod.
 Why not just come over to the club meeting at Huntersville on the third Saturday of each month and bring your motors and I can tell you the answer just buy looking at the motors. If you want to come over to my house we can do a correct rebuilt of your motors in a short time. Check with Howard as to the meetings to be sure we are having one. I live just east of Charlotte but come over to Greenville ofter as my daughter lives there.
Ed

[Bob Reeves]

Out of 10 examples all the ones without muffler lugs have a thinner sleeve and the ones with muffler lugs have a thicker sleeve that won't fit in the earlier case. Everything else except of course the heads seem to be interchangeable. However this is a pretty small sample with no two ring engines but you can probably bet your older sleeves won't fit the muffler lug engine.

[frank williams]

With the ST60's and I think also the 46's, the thin sleeve engines were guaranteed to be chormed.  You can see the chrome flashing on the exhaust port webs.  The thick sleeve motor, at least in the 60's, were not chromed, even though it said so on the case.  The older 46 has a smaller bypass (better for stunt).  I think the motor without ears is a better motor, just my opinion.

[David Matthews]

Ed,

I'm sure I don't want the ST46 if it is a double ring motor, all of the pistons I have are single ring. I'm not sure if the liners I have are the heavy or thin wall as I bought them a while back and would have to know the thicknesses to measure them.
As far as knowing what to do in rebuilding, my neighbor in Cincinnati was Fran Abt who did motors behind the scenes for some top fliers in the 70's and 80's and I was around when he did them.  I did my own rebuilds under his direction.

I guess I should back out of the ST46 deal after reading Bob's email til I know a little more about the liners I have.

I planned on changing over to the ST51's when I started building. If I had trouble finding a engine case or two I might just get rid of my ST46 parts.

Til March I don't think I'll be able to make it to Huntersville as I'm only home on the weekend, don't want to upset the little woman. I wouldn't mind meeting you in Greenville to do some flying down the road if there is a place we can do it at. If you would like I can send you my cell number.

Thanks for the input Bob & ED it is appreciated.
Dave Matthews

[Bob Reeves]

Doesn't mean you should give up on 46's, bout all that a worn one needs to run like new is a Bowman ring and maybe bearings. If you get the eared 46 you will be able to tell what liners you have which will make selling the parts easier should you decide to...

[RandySmith]

St 46s  Were made with thin sleeve no ear and  thick sleeve no ear case

There were also thick sleeve  no ear cases and  thick sleeve  eared  cases

I have never ran into a thin sleeve  eared case

Some of the thick sleeves  were chromed, most were not

There were at least 6 differant rods and  at least 6 differant crankshafts

there were also differant crank timings  as  well as  short rods  and  long rods

2 and 1 ring motors


Regards
Randy

[Dallas Hanna]

To put a size on things, the difference between the thick and thin liner was 0.5mm on diameter.

HH

[EddyR]

Also there is the banded crank. I had one of those come apart on my flyoff flight at the King Orange many years ago. The only part not damaged was the head and crank. I repaired the crankcase many years later and used it in  one of the  motors that I did the ABC set up in . It is a eared motor with the ears removed. narrow thrust washer.
Ed

[Phil Spillman]

Hi Dave, Great to have seen you at Huntersville! Thanks for the nice words! You certainly are most welcome and if ever I may be of any assistance just give me a shout! My new email is here in the profile section.

As to this immediate deli-ma, I really don't know the ST .46 except by reputation and by having watched other es fly really well. I suppose that which ever one you get it will be made to run much better if touched by a capable rework artist! That said I believe that you may be able to add muffler lugs to an unlugged case by the use of PC 7. This is similar to JB Weld be stronger, so I have been told. you could use brass tubing with an ID to accommodate your muffler's screw holes of course with the appropriate bolts.

Best of luck coming back to UC! Your Cardinal would also fly quite well with an OS .46 LA. More easy to come by and less of a queen with no ball bearings or rings to worry with!

Best Regards,

Phil Spillman