Further ideas for improving the stunt run of the ST51
Stuka Stunt Main Forum · 19 of 19 known posts recovered
I have been looking for a way to fit a plug shield like the retro to the ST51. I think that I have found a way and just finished implementing it. I plan to test it next weekend and will report back.
http://www.machineconcepts.co.uk/aeromodelling/st51/st51-3.htm#top
So just what do you consider a good "stunt run"? My ST51 is from Tommie Lay, and it runs about as good as an engine could be expected.
Consistent fast 4-cycle throughout the pattern. It has enough power to make the 2- cycle break unnecessary.
Floyd in OR
>So just what do you consider a good "stunt run"?
>My ST51 is from Tommie Lay, and it runs about as good as an
>engine could be expected.
>Consistent fast 4-cycle throughout the pattern. It has enough
>power to make the 2- cycle break unnecessary.
>
>Floyd in OR
Ya but I don't see Tom or any of the other reworkers on here spelling out exactly what they do.
Way to go Mike... This is meat and potatoes kinda stuff unlike the other large percentage of posts that are just BS.
>>So just what do you consider a good "stunt
>run"?
>>My ST51 is from Tommie Lay, and it runs about as good as
>an
>>engine could be expected.
>>Consistent fast 4-cycle throughout the pattern. It has
>enough
>>power to make the 2- cycle break unnecessary.
>>
>>Floyd in OR
>
>Ya but I don't see Tom or any of the other reworkers on here
>spelling out exactly what they do.
>
>Way to go Mike... This is meat and potatoes kinda stuff unlike
>the other large percentage of posts that are just BS.
Gee Bob, don't you think it would be rather silly of Tom or the others to state exactly what they do? I mean if you are making money doing this why would you tell everyone what you are doing so as to put yourself out of business?
Bill Morell
Ontario, California
Better to have it and not need it than it is to need it and not have it.
Tom Lay mentioned the scope of his rework on most engines. He replaces the ring with a Bowman ring, hones the cylinder to make it really round. Not sure, but I think he also puts in high quality ball bearings. Unlike some engine gurus, I don't think Tommie messes around with port timing.
Floyd
>Tom Lay mentioned the scope of his rework on most engines.
>He replaces the ring with a Bowman ring, hones the cylinder to
>make it really round. Not sure, but I think he also puts in
>high quality ball bearings. Unlike some engine gurus, I don't
>think Tommie messes around with port timing.
>
>Floyd
Not exactly so. Maybe tom should weigh in here. I know he is not using Bowman rings and does not replace the bearings.
>>Tom Lay mentioned the scope of his rework on most
>engines.
>>He replaces the ring with a Bowman ring, hones the
>cylinder to
>>make it really round. Not sure, but I think he also puts
>in
>>high quality ball bearings. Unlike some engine gurus, I
>don't
>>think Tommie messes around with port timing.
>>
>>Floyd
>
>Not exactly so. Maybe tom should weigh in here. I know he is
>not using Bowman rings and does not replace the bearings.
>
This is a interesting claim. I had a G/21 40 rebuilt by Tom awhile back. He said that he uses Bowmans rings and replaces the bearings with Boca bearings. Frank says that he uses his rings as well. I can't really see having a engine done if these aren't part of it. The only thing that he doesn't make clear are "several internal mods" that he does. Thats his business. Its the end result that we are paying for.
Bill Morell
Ontario, California
Better to have it and not need it than it is to need it and not have it.
>>>Tom Lay mentioned the scope of his rework on most
>>engines.
>>>He replaces the ring with a Bowman ring, hones the
>>cylinder to
>>>make it really round. Not sure, but I think he also
>puts
>>in
>>>high quality ball bearings. Unlike some engine gurus,
>I
>>don't
>>>think Tommie messes around with port timing.
>>>
>>>Floyd
>>
>>Not exactly so. Maybe tom should weigh in here. I know
>he is
>>not using Bowman rings and does not replace the bearings.
>>
>
>This is a interesting claim. I had a G/21 40 rebuilt by Tom
>awhile back. He said that he uses Bowmans rings and replaces
>the bearings with Boca bearings. Frank says that he uses his
>rings as well. I can't really see having a engine done if
>these aren't part of it. The only thing that he doesn't make
>clear are "several internal mods" that he does.
>Thats his business. Its the end result that we are paying
>for.
When was the last time you checked with Tom on what he is doing with the ST 51?
>>>>Tom Lay mentioned the scope of his rework on
>most
>>>engines.
>>>>He replaces the ring with a Bowman ring, hones
>the
>>>cylinder to
>>>>make it really round. Not sure, but I think he
>also
>>puts
>>>in
>>>>high quality ball bearings. Unlike some engine
>gurus,
>>I
>>>don't
>>>>think Tommie messes around with port timing.
>>>>
>>>>Floyd
>>>
>>>Not exactly so. Maybe tom should weigh in here. I
>know
>>he is
>>>not using Bowman rings and does not replace the
>bearings.
>>>
>>
>>This is a interesting claim. I had a G/21 40 rebuilt by
>Tom
>>awhile back. He said that he uses Bowmans rings and
>replaces
>>the bearings with Boca bearings. Frank says that he uses
>his
>>rings as well. I can't really see having a engine done if
>>these aren't part of it. The only thing that he doesn't
>make
>>clear are "several internal mods" that he does.
>>Thats his business. Its the end result that we are paying
>>for.
>
>When was the last time you checked with Tom on what he is
>doing with the ST 51?
>
Never have and haven't had any reason to. All I said was that he rebuilt a G/21 40 and stipulated that he used Frank Bowmans rings and Boca bearings. If he has changed that I wasn't aware of it. It has been less than 6 months ago that he rebuilt my 40. If he is not changing the ring or the bearings I would like to know just what it is that he is doing? But like I said that is his business.
Bill Morell
Ontario, California
Better to have it and not need it than it is to need it and not have it.
>>>>>Tom Lay mentioned the scope of his rework on
>>most
>>>>engines.
>>>>>He replaces the ring with a Bowman ring,
>hones
>>the
>>>>cylinder to
>>>>>make it really round. Not sure, but I think
>he
>>also
>>>puts
>>>>in
>>>>>high quality ball bearings. Unlike some
>engine
>>gurus,
>>>I
>>>>don't
>>>>>think Tommie messes around with port timing.
>>>>>
>>>>>Floyd
>>>>
>>>>Not exactly so. Maybe tom should weigh in here.
>I
>>know
>>>he is
>>>>not using Bowman rings and does not replace the
>>bearings.
>>>>
>>>
>>>This is a interesting claim. I had a G/21 40 rebuilt
>by
>>Tom
>>>awhile back. He said that he uses Bowmans rings and
>>replaces
>>>the bearings with Boca bearings. Frank says that he
>uses
>>his
>>>rings as well. I can't really see having a engine done
>if
>>>these aren't part of it. The only thing that he
>doesn't
>>make
>>>clear are "several internal mods" that he
>does.
>>>Thats his business. Its the end result that we are
>paying
>>>for.
>>
>>When was the last time you checked with Tom on what he is
>>doing with the ST 51?
>>
>Never have and haven't had any reason to. All I said was that
>he rebuilt a G/21 40 and stipulated that he used Frank Bowmans
>rings and Boca bearings. If he has changed that I wasn't aware
>of it. It has been less than 6 months ago that he rebuilt my
>40. If he is not changing the ring or the bearings I would
>like to know just what it is that he is doing? But like I said
>that is his business.
Bill,
I emailed him probably within the last month about the rings. I had several ST 51 done by him in September of last year and I noticed that they didn't have Bowman rings in them. He said he now sends out the stock ring with the cylinder when he gets them hardened. sometime ago, I asked him about whether he replaces the bearings and he told me no but he "reworks" (my words) them to make them smooth. that is why I said tom should weigh in here.
>>>>>>Tom Lay mentioned the scope of his rework
>on
>>>most
>>>>>engines.
>>>>>>He replaces the ring with a Bowman ring,
>>hones
>>>the
>>>>>cylinder to
>>>>>>make it really round. Not sure, but I
>think
>>he
>>>also
>>>>puts
>>>>>in
>>>>>>high quality ball bearings. Unlike some
>>engine
>>>gurus,
>>>>I
>>>>>don't
>>>>>>think Tommie messes around with port
>timing.
>>>>>>
>>>>>>Floyd
>>>>>
>>>>>Not exactly so. Maybe tom should weigh in
>here.
>>I
>>>know
>>>>he is
>>>>>not using Bowman rings and does not replace
>the
>>>bearings.
>>>>>
>>>>
>>>>This is a interesting claim. I had a G/21 40
>rebuilt
>>by
>>>Tom
>>>>awhile back. He said that he uses Bowmans rings
>and
>>>replaces
>>>>the bearings with Boca bearings. Frank says that
>he
>>uses
>>>his
>>>>rings as well. I can't really see having a engine
>done
>>if
>>>>these aren't part of it. The only thing that he
>>doesn't
>>>make
>>>>clear are "several internal mods" that
>he
>>does.
>>>>Thats his business. Its the end result that we
>are
>>paying
>>>>for.
>>>
>>>When was the last time you checked with Tom on what he
>is
>>>doing with the ST 51?
>>>
>>Never have and haven't had any reason to. All I said was
>that
>>he rebuilt a G/21 40 and stipulated that he used Frank
>Bowmans
>>rings and Boca bearings. If he has changed that I wasn't
>aware
>>of it. It has been less than 6 months ago that he rebuilt
>my
>>40. If he is not changing the ring or the bearings I
>would
>>like to know just what it is that he is doing? But like I
>said
>>that is his business.
>
>Bill,
>I emailed him probably within the last month about the rings.
>I had several ST 51 done by him in September of last year and
>I noticed that they didn't have Bowman rings in them. He said
>he now sends out the stock ring with the cylinder when he gets
>them hardened. sometime ago, I asked him about whether he
>replaces the bearings and he told me no but he
>"reworks" (my words) them to make them smooth. that
>is why I said tom should weigh in here.
>
Crist, that would be nice if Tom would. I have several of the 51's but haven't never used any of them. Currently making good ballast for the engine cabinet.
Bill Morell
Ontario, California
Better to have it and not need it than it is to need it and not have it.
According to Tom's advertisement in the latest Stunt News, he still fits a Bowman ring and new bearings to the ST51.
Mike
I guess it depends whether the gas heads straight for the plug, or sort of clings to the side of the cylinder walls and heads up and over the top, in which case it will go straight behind the bar. Proof of the pudding will be in the eating :-)
Stunt Rule No.1 - Stunt fliers love to fiddle with things.
Ian R.
Hey! Wait a minute. That cylinder head looks familiar! ;->
[photo not recovered: 29334.gif]
"A mathematician is a device for converting coffee into theorems." -Paul Erdos
Who else works on the ST G51 besides Tom Lay?
GUY BLANKINSHIP
AMA 14272
>Who else works on the ST G51 besides Tom Lay?
>
>GUY BLANKINSHIP
>AMA 14272
RANDY SMITH AT AERO PRODUCTS
AND BRYON BARKER AT C.F. SLATTERY CO.
Greg L. Bahrman
You have a very interesting web site!
With the "sandwich" of stuff in the head, do you feel the need to use an in-oz (the metric equiv in your case) torque wrench to tighten the head bolts evenly?
Larry Fulwider
I don't think that I should need any special tightening methods. The bar is a press fit into the slot and is also backed up with a drop of Loctite. The 0.6mm alumnimum shim is glued down onto a very thin film of JB Weld and it was all pressed together for a day while the glue hardened. The JB Weld is there mainly to ensure a seal and to make sure that the shim is flat. I expect to need a couple of thin shims to get the compression back to the right setting but only careful testing will indicate what is needed.
