What is recommended fuel ?
Getting ready to use one for the first time.
I wasnt flying stunt back in the glory days of the Super Tigre's..
What are materials of piston / sleeve ??
Will be using on a profile around 46~48 oz.
What are some good props to try, prefer wood ?
Hi Alan
You will find that a huge number of props work with the ST 46, depending on what is needed for your particular setup.
We used Rev-up 12 x 5 at full span or cut to 11.5, This was before Bolly props,and as Brett mentioned Bolly has many props that worked well.
Many other props work well too, The BYO 12 x 5, Top Flight 12 x 5, Rev-Up 11 x 6 EW, this will depend on what plane, how much weight, size, etc
In what is out there today to buy, The BYO 11x6 11 x 5 12x 5 ... 12x6 Zinger pro series 12 x 5, Eric Rule has some very good wood props that may work also, I know some are using the Power point TF props on 46s. So you have a lot to choose from.
I always used 50-50 oil with about 23% total in mine. The ST 46 will pull as 46 to 48 ounce profile with little effort, as it is a very strong motor.
The engine ,if new needs to be broken in very slow and carefully, As Brett stated The early ones, without muffler lugs were chromed, Every St 46 I had seen with muffler lugs did not have a chrome liner stock. Also the early chromed liner were much thinner than the later motors.
The chrome liners take more running time for ring breakin than the newer ones do, The rings are the key to any motor that uses them as Brett stated. The BIG problem with ST 46 rings were, many had zero gap when sent.
These would heat up as soon as you run them, the gaps would touch and the ring would start to wear flat on part of it from the heat.
If you were not very careful ,one run like this would ruin the ring were it would never seal right.
Even many of the replacement rings ST sent would have no gap, replacing the ring without measure and setup would result in the same results.
I have setup 100s of ST 46s and I always used .003 to .004 initial gap on chrome motors and .002 to .003 on Steel ones that were not chromed.
If the sleeve was honed with a coarse cross hatch (the swirling scratches cut into the sleeve in 2 spiraling directions) you could set the gap at .001, as the ring would wear and open up much more quickly.
When you got a great ring seal it lasted for a while, as long as you didn't get a lean run.
Other things that would benefit the ST 46 and make it a better motor was to replace the venturie with a true venturie or block off 3/4 of the groove cut into the fuel feed part of the ST venturie.
This helps with stopping the surging at the end of the tank.
Also the stock ST 46 venturie was pretty small, as the ones came with .150 to .157 diameter, We used 160 to 175 diameter holes in them, however the stock small one will work in the small plane you are talking about flying. There are many other things that will improve the ST 46 but that is another thread.
Regards
Randy