Rework ST G51 Control Line Engine??

I recently purchased a new made in Italy ST G51 Ringed C/L Engine.
Should this engine be sent to be reworked for a decent stunt run? If not what fuel,prop,etc should I use?
Thanks for your help.
Regards Newell

A quick search under "ST-51" will turn up volumes of info on this motor, both in set up, state of tune,..who to talk to etc. There are two camps really,..those that like the rework tweeks and those that run them box stock for the most part. The stock muffler, being a heavy weight piece is typically left in the box. The condition and fit of the piston ring is a normal item to check and in many cases replaced by a Frank Bowman piece. The stock rings wear quickly, it's reported, and ring end gap is often not correct, at least on the Chicom 51 Tigre's. The search will give mush info.

The ones actually made in Italy have much better Quality Control that those produced in China. I would think, just fly it. If you want it set up perfectly, send it to Tom Lay or Randy Smith. Be asvised Tom sets them up to run best on all "Castor" fuel. Randy sets them up a bit differently for use with partial synthetic lube fuels.


Jim Pollock

Jim,
The Tom Lay reworked ST 51's come with a statement from Tom to break it in using all castor and then if you'd like switch to 50/50 mix. I have followed Tom's advice and used all castor for break in and after that I use SIG Champion 50/50 castor/synthetic oil.

Edited because I noticed that you said runs best on all castor. I can't comment if they run best on all castor because I use a blend for oil.
Respectfully,

I sent my China ST51 motor to Frank Bowman before I ran it. It had the rod installed backwards and had a bad head seal. Frank reinstalled the rod correctly put his ring in it and lapped the head to the sleeve for a good fit. I have seen others that were just fine stock.

I've had two (one Italian and one Chinese version) one reworked by Randy Smith and one by Byron Barker, both did great work and had strong runs.

James

Hi Newell,

I have run the ST 51 a lot. I really like the engine and believe it is very underrated! I will say that all of mine have been breathed upon by a reworker (Tom Lay or Randy Smith) and I have only "seen" stock ones run. But they did run well! I like the idea of the engine being "blueprinted" before I use it, just makes me more comfortable.....

Big Bear <><
Character: It's what you do when no one else is watching.