ID needed for Johnson .35

I have just been asked by one of our club members without net access for some help in identifying and dating a Johnson .35. I can't help him as the only Johnsons I ever saw were the combat specials. There is a rather blurry photo that should be enough for an experienced eye to recognise.

He writes
I could use your help. Today I bought a Johnson35 at a swap meet. Photos are attached. I need to date it and get some documentation for vintage stunt.Photos are attached but I reckon it may be a very early model - has triangular backplate and angled exhaust - like early frog 500.Havent yet got it apart (gummed)but case is perfect, what I can see of piston looks without scores.
Also bought a mint - unrun red head (Testors)McCoy 19. Anyone know earliest production date please and able to document.

If anyone can help, I am sure that he would appreciate it.

I had three Johnson 35's just like that one and they are the standard stunt motor from Johnson from the mid 50's. The instructions that came with the motor said no break in needed but I found them to be just the opposite and gave them a long break-in. I used one in old time stunt for 15 years and then used it for slow combat.They had a very small restrictor in them from the factory but all I have seen did not have it and so many people thought that they were not good for stunt.The ones I used for stunt ran a very strong 4-2-4 stunt run.They will draw fuel ok without the restrictor so many people don't use one but the stunt run is not good.These early Johnson's are just reworked Orwick's. I think they have a domed piston head.
Ed

LAST EDITED ON May-07-06 AT 09:07 AM (CST)
 
Charlie, -- If it has a 4-Bolt Head, it was produced in 1955 or 1956. If it has a 6-Bolt Head, it was produced from 1957 to 1959.
This is the Small Case Johnson as opposed to the Large Case Johnson's which were Ball Bearing engines (except for a few at the end), like the Stunt Supreme and the Combat Special.

The very first Johnsons, in 1955, used Orwick parts and were iridescent green.

This info comes from Frank Anderson's Blue Book.

Bob Jones

Edited to correct error, after 1959 all Johnsons were the Large Case type. They were produced until 1963.

LAST EDITED ON May-07-06 AT 03:27 PM (CST)
 
The later small shaft Johnson 35 was their combat engine. The later small shaft S was the stunt engine. Before the S came out, I am unsure what the 35 was meant for. I have a fair assortment of Johnsons.

>The later small shaft Johnson 35 was their combat engine.
>The later small shaft S was the stunt engine. Before the S
>came out, I am unsure what the 35 was meant for. I have a
>fair assortment of Johnsons.
As I remember? The S came about as a result of mixing 29 & 35
parts, in an emergency( George Aldrich & Hi Johson ) and coming up with a very good stunt engine. Actually a 32+-.
Can,t remember If It was the crank or piston that was changed ,but know it made a really good running unit.

The "S" is a 33 and has the 35 piston, cylinder, and head with a 29 crank. One is the results of this combo is a very low (for a Johnson) compression ratio - something in the 6.5 to 1 range. There was also a 32 which had its own bore and stroke.
Steve

It was the .29 Crankshaft that was put into GMA's .35 Johnson, which resulted in the S engine

.29 - Bore .718, Stroke .718
.32 - Bore .750, Stroke .718
.35 - Bore .770, Stroke .750
(S) - Bore .770, Stroke .718 -- which gives a dispacement of .334

I really like the S. Have one on a Super Ring right now. Runs like a Fox, including the Dreaded Fox Burp on sidewinder mounts, too.

Also, had some good luck with a Sport Special Large Case .36.

In 1957/8, that was the engine for rat race, esp. 1400lap,and that was the engine to put on a Flight Streak, or Quicker.

Just a tiny correction to an earlier post. The big case Johnsons were not ball bearing engines as I recall. They had a very large diameter crankshaft thus the very bulky case that gave every indication of ball bearings, but a peak inside showed a bush. Sort of like a lady cross dresser, I guess (sorry, Len. Couldn't help myself)

I flew an SS (Stunt Supreme) in my oversized rip off of Billy's Ares at the 1967 nats. It was OK but the power difference wasn't really enough to make up for the additional weight compared to the little case 's' IMHO.

The Johnson RC engines were ball-bearing as were the 36BB engines.

I've had both ball bearing and plain bearing big-case Johnsons.

The plain bearing large case version says nothing on the side of the case where the displacement ususally goes or the SS or CS for those versions. The ball bearing version has a BB.

Bill

The large shaft Johnson with the symbol milled out (erased), is the Sport Special. It was the BB case with aluminum bushings instead of bearings installed. The O.D. of the bushing was oversize, so you couldn't remove them and install bearings.

Ted and Steve are correct. Johnson literature lists the JRC & the JBB as the only Johnsons that utilized two Ball Bearings. They both had a displacement of .358. The other Large Case Johnsons were: JCS Combat Special, .358 Disp., JSS Stunt Supreme, .348 Disp., J29R Racing, .289 Disp., these three were Plain bearing engines. Compression Ratios were listeed as:
J29R ----- 9.8-1
JSS ------ 6.5-1
JCS ------ 10.8-1
JRC ------ 10.8-1
JBB ------ 10.8-1