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Engine basics => Engine set up tips => Topic started by: frank mccune on March 08, 2016, 12:22:43 PM

Title: What makes a ST .49 a ST.51?
Post by: frank mccune on March 08, 2016, 12:22:43 PM

        Hi All:

        I have a ST .49 engine that looks like the ST .51 that Brian Gardner is making .51 pistons and cylinders for stunt use.  Will his .51 parts fit into my .49 engine ala Fox .29 and .35 Stunt engines from yesteryear? Perhaps the cylinder walls are a bit thinner to make the .51 displacement.

       I have been told that my .49 ST was only produced for one year.  Both my .49 and my friend's .51 are excellent Stunt engines.

      Any insight about the p&C swap or when the .49 was produced?

                                                                                                 Tia,

                                                                                                 Frank McCune

Title: Re: What makes a ST .49 a ST.51?
Post by: RandySmith on March 08, 2016, 12:42:35 PM

Quote from: frank mccune on March 08, 2016, 12:22:43 PM

        Hi All:

        I have a ST .49 engine that looks like the ST .51 that Brian Gardner is making .51 pistons and cylinders for stunt use.  Will his .51 parts fit into my .49 engine ala Fox .29 and .35 Stunt engines from yesteryear? Perhaps the cylinder walls are a bit thinner to make the .51 displacement.

       I have been told that my .49 ST was only produced for one year.  Both my .49 and my friend's .51 are excellent Stunt engines.

      Any insight about the p&C swap or when the .49 was produced?

                                                                                                 Tia,

                                                                                                 Frank McCune

Maybe   can you measure the oldside sleeve diameter?  also the top lip on the sleeve

Randy

Title: Re: What makes a ST .49 a ST.51?
Post by: M Spencer on March 08, 2016, 06:55:21 PM

The 40 & 49 SPORT are single ball race motors .

the 51's twin ball race , with a big lump where they machined a slot where it said ' SPORT ' on the side, in the die .

Dunno on the bore & stroke , etc .

Title: Re: What makes a ST .49 a ST.51?
Post by: frank mccune on March 09, 2016, 07:10:38 AM

      Hi Matt:

      Good to her from you.

      The engine in question looks like the ST .51 that are having p&c  made as an upgrade.  It has two ball bearings.  I do not remember any mention of the word sport on the engine.  I will check that matter.

      I doubt that my friend would permit me to pull the head on his .51 to take some measurements to compare his engine to my .49.  What are friends for? Lol 

     I have a stash of ST G/20 .15 engines for sale both Diesel and glow.  Could you fence them for me in The Land Down Under?

                                                                                    Stay well my friend,

                                                                                    Frank