Johnson "S" versus Johnson "SS"

[Bill Morell]

Anyone know if there is much  difference in these 2 versions other than the case?

[Bill Morell]

If I recall, the SS was for Stunt Supreme and S was Sport. CS was for combat special.

The "S" is a designated stunt engine from combining a 29 crank in a 35 case. I am just curious as to how they compare? I can put either one in my new plane. Obviously the "S" is lighter due to the small case.

[Steve Lotz]

I suspect the SS would use more fuel than the S because of the big gas passage in the crank. It is probably heavier, too. Some people have criticized the SS as not really being a stunt engine as it has some of the run characteristics of the CS.

For what I do, I'd take an S over an SS.

[Steve Lotz]

If you use the SS, make sure the prop is on TIGHT. That soft cast prop driver likes to egg out the D hole.

[Bill Morell]

Thanks Steve! You have pretty much answered my question. The weight factor I was already considering. I have several of each so now I'll be looking for the best one.

[Tony Drago]

TY is correct.
S--Stunt. SS--Stunt Supreme. CS--Combat special
 Putting the 29 cranks in the 35 would give you a 32. Came out for free flight.

[Dennis Toth]

The S is a little heavier than the Fox and the SS a bit more. If you run the SS with a current high rpm/ low pitch set up it will haul the mail!! The Johnsons had lots of power and back in the day some considered them too much power for stunt. Others know how to work them and would let them have their head and power through any conditions. Larry Scarinzi was one of them with the Grey Ghost. Bring the pitch down to around 4 and push the diameter up to 10 1/2 - 11" and run 10% N, 25 -27% total oil (50/50 castor/syn ok) and it will do great.

Best,   DennisT

[Bill Morell]

TY is correct.
S--Stunt. SS--Stunt Supreme. CS--Combat special
 Putting the 29 cranks in the 35 would give you a 32. Came out for free flight.

As far as I know the "S" came about from Hi Johnson helping Bob Palmer at a contest. .33 in displacement.

[Bill Morell]

The S is a little heavier than the Fox and the SS a bit more. If you run the SS with a current high rpm/ low pitch set up it will haul the mail!! The Johnsons had lots of power and back in the day some considered them too much power for stunt. Others know how to work them and would let them have their head and power through any conditions. Larry Scarinzi was one of them with the Grey Ghost. Bring the pitch down to around 4 and push the diameter up to 10 1/2 - 11" and run 10% N, 25 -27% total oil (50/50 castor/syn ok) and it will do great.

Best,   DennisT

Dennis, you nailed it on what it is intended for.

[Steve Lotz]

The story I heard involved Hi Johnson and George Aldrich.

[Bill Morell]

That might be correct. My occasional "senior moment". I knew it happened at a contest.

[Phil Spillman]

Both engines exhibit sub-piston induction which means that if you run or have to run mufflers their running may not be up to par. By all means check to see if the bottom of the piston skirt comes above the exhaust port you'll have sub-piston induction which may not be as spiffy as you'd like!

Phil Spillman

[Bill Morell]

Both engines exhibit sub-piston induction which means that if you run or have to run mufflers their running may not be up to par. By all means check to see if the bottom of the piston skirt comes above the exhaust port you'll have sub-piston induction which may not be as spiffy as you'd like!

Phil Spillman

Thanks Phil. I'm contemplating switching it to the OS Max 35S. Haven't made a firm decision yet but giving it a fair amount of consideration. I can't do much of anything right now as I'm waiting for the control horn to arrive.