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Engine basics => Engine set up tips => Topic started by: Dennis Holler on March 24, 2022, 04:11:55 PM

Title: ST.56 early
Post by: Dennis Holler on March 24, 2022, 04:11:55 PM
Is this one of those early plain bearing .56's or is it really late.  I see it has the carb screws centered on the throat versus the pinch nut I am used to seeing.  What else is different between this and the later ball bearing versions? is the liner and piston the same?
Title: Re: ST.56 early
Post by: M Spencer on March 24, 2022, 06:57:30 PM
(http://sceptreflight.com/Model%20Engine%20Tests/ST%2056%20page%202.jpg)

(http://sceptreflight.com/Model%20Engine%20Tests/ST%2056%20page%201.jpg)

Far as I can figure , yours s a THIRD series . How many of the earlier four versions were differant / , good question ! .

First had lapped iron piston , and siezed a bit often in good ole U S A Summers , or the ( then ) usual close tolerance
hardened linerm took forever to run in fully . So openingem up early , they locked up .Seeing most people put them
straight in a plane and flew them .
==========================================================================
UNLIKELY its a SINGLE RING . ?
The two ring has the shorter rod . ( same as 51 & first 60 , single ring rods , theres two ' fits '  51 & 60 , maybe the 56 is the 51 one .)

EARLY 60s & 46's had thinner liners , larger / smaller case bore , to fit . The 56 would be similar perhaps .
The Dual ring being the one with the thinner liner .

=========================================================================

Got parts catalouges  , but not currently accessable . From Memory , the 56 parts swap out , B B to P B , bar where obvious ,
Im told the 56 & 60 run differant head bolt pitch circles . Wider head bolt pattern on 60s .

As Super Tigre might vary specs between runs , mikeing up ( Virneer ) check / comparison , even for the " right Part " is adviseable .
sometimes some people put production line reject parts , in the ' spares ' packets , on odd occasions . also .
Title: Re: ST.56 early
Post by: M Spencer on March 24, 2022, 07:15:41 PM
(http://sceptreflight.com/Model%20Engine%20Tests/ST%2056%20page%202.jpg)

(http://sceptreflight.com/Model%20Engine%20Tests/ST%2056%20page%201.jpg)

Far as I can figure , yours s a THIRD series . How many of the earlier four versions were differant / , good question ! .

First had lapped iron piston , and siezed a bit often in good ole U S A Summers , or the ( then ) usual close tolerance
hardened linerm took forever to run in fully . So openingem up early , they locked up .Seeing most people put them
straight in a plane and flew them .
==========================================================================
UNLIKELY its a SINGLE RING . ?
The two ring has the shorter rod . ( same as 51 & first 60 , single ring rods , theres two ' fits '  51 & 60 , maybe the 56 is the 51 one .)

EARLY 60s & 46's had thinner liners , larger / smaller case bore , to fit . The 56 would be similar perhaps .
The Dual ring being the one with the thinner liner .

=========================================================================

Got parts catalouges  , but not currently accessable . From Memory , the 56 parts swap out , B B to P B , bar where obvious ,
Im told the 56 & 60 run differant head bolt pitch circles . Wider head bolt pattern on 60s .

As Super Tigre might vary specs between runs , mikeing up ( Virneer ) check / comparison , even for the " right Part " is adviseable .
sometimes some people put production line reject parts , in the ' spares ' packets , on odd occasions . also .

Far as I know , it might be plain head , lapped .
                                   Low finned head , various P/L
                                 Tall finned Head , Dual Ring ( & perhaps later a single ring ? )

Have you that engine in your mitt , or is it a picture picked at random ?

ALSO there may well be the sub piston induction at the ex Port edges , with the piston at the T D C .

Opps . mw~
Title: Re: ST.56 early
Post by: Dennis Holler on April 09, 2022, 03:45:03 PM
I got it now, was out of town for work for a couple of weeks.  It is pretty gummed up so I am soaking it now, may toss it in a crock pot if it chooses to stay stucky