*** CLUB SUPER TIGRE ***
#1901
A workaround for engines without a pinned ring was a bridge across the port(s). Some hop-ups include removing the bridge when using a pinned ring to replace the stock one. Removing the bridge increases the flow; replacing the ring with a Bowman pinned ring increases the performance due to improved compression from better sealing rings and and reduced ring blow-by from smaller ring end gap.
#1902
While true, most of the ringed engines with pinned rings I've had apart have a bridged exhaust port. One has to consider the transfer ports as well - many liners I've seen have transfer ports that are longer horizontally than they are vertically. While the exhaust port is often the widest port, that isn't the only one that would be wide enough to snag a ring. In the case of my Fox .50 and likely most other B-case Foxes, the transfer port is split into two narrow ports running vertically at an angle as well as having a bridged exhaust port.
#1903
Just remembered , i run my ST 45 and 51 on a long K&B 1L with an idle bar
The long K&B 1L ( no idle bar) has been my favorite glo plug for 30 years of two cycle glo ,and i use it in every kind of engine , and they all burn ,Morgan Omega 15%
You can run --this fuel --and be sure you are protecting your engines 100% , a castor and syn mix
Enjoy
The long K&B 1L ( no idle bar) has been my favorite glo plug for 30 years of two cycle glo ,and i use it in every kind of engine , and they all burn ,Morgan Omega 15%
You can run --this fuel --and be sure you are protecting your engines 100% , a castor and syn mix
Enjoy
#1906
All of my Tigres are the older Italian manufactured versions and none of them like to run on 15% nitro. My little .29 will run okay on 10%, but the rest much prefer 5% nitro or less. I use McCoy MC59 plugs in mine that still run on glow fuel. I have a diesel head on a .45 that I'd gotten from a stellar fella here on RCU.
#1907
The Enya 6002 (both the 40 and 45) are baffled piston engines so the transfer and exhaust ports have multiple bridges to hold the ring in place as do all other non Schneurle engines. My OS 40SR needed a new ring which is unpinned but has a bridge in the exhaust port but Frank's list only showed a pinned ring. I queried him before ordering one and his reply essentially said Oops, got that wrong .
#1908
The Enya 6002 (both the 40 and 45) are baffled piston engines so the transfer and exhaust ports have multiple bridges to hold the ring in place as do all other non Schneurle engines. My OS 40SR needed a new ring which is unpinned but has a bridge in the exhaust port but Frank's list only showed a pinned ring. I queried him before ordering one and his reply essentially said Oops, got that wrong .
S series are pinned, G series are pinned, X series are mostly all pinned. V series are mostly unpinned. The G21 series are unpinned. FWIW.
Last edited by 1QwkSport2.5r; 01-13-2016 at 06:24 PM.
#1909
Junior Member
Join Date: Oct 2009
Location: alton, VA
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
Gs40 good right out of the box the 51 gave me a fit for over a year. One day with no changes it starting running like a raped ape and five years and a few gallons is the best engine I have. I do have some OS , Magnums, and some Aviastars. It idles perfect ,instant transition, and screams with a 11x6 on an old Tower trainer. When Tower gets them back in stock I will get a couple more 51's.
#1910
Senior Member
Join Date: Apr 2005
Location: goolwasa, AUSTRALIA
Posts: 1,680
Likes: 0
Received 0 Likes
on
0 Posts
Gs40 good right out of the box the 51 gave me a fit for over a year. One day with no changes it starting running like a raped ape and five years and a few gallons is the best engine I have. I do have some OS , Magnums, and some Aviastars. It idles perfect ,instant transition, and screams with a 11x6 on an old Tower trainer. When Tower gets them back in stock I will get a couple more 51's.
#1911
My Feedback: (2)
Join Date: Dec 2001
Location: Kerrville,
TX
Posts: 2,127
Likes: 0
Received 0 Likes
on
0 Posts
All of my Tigres are the older Italian manufactured versions and none of them like to run on 15% nitro. My little .29 will run okay on 10%, but the rest much prefer 5% nitro or less. I use McCoy MC59 plugs in mine that still run on glow fuel. I have a diesel head on a .45 that I'd gotten from a stellar fella here on RCU.
I see you live where the altimeter is ~800 MSL. Don't know about the summer humidity.
CR
#1912
I tried running a tank of 15% through my S90K in the fall and it crackled like no tomorrow. I stopped at a couple ounces and went to 5% and the crackle went away. I just stick to 5% most of the time; it's a safe bet - at least where I live. At higher elevations, the extra nitro helps with the lack of oxygen in the thinner air. I'll have to remember to keep that in mind when I give advice.
#1913
The St 51 needs a -long --break in period , for it to develope its full power
One of my longest break in runs ,i can remember ,to get the engine to transition ,to get the NVs set correctly , on a bench
About a 1/2 gallon or so
Do realize during break in ,the cool down period between engine runs , is as important ,as running the engine itself
The engine must be completely cool ,at your next start up to evaluate your NV settings and see if they need adjustment ,again
If an engine starts to run hot and odd (because it was run lean) let the engine cool down completely ,then start it and reajust the Nvs
The pinch the tubing test, will run the engine up to max RPMS ,on the high and low speed NVS
Record the sound in your head and run the engine 2-300 off the max RPM ( SB 2-3 clicks richer ,than max RPM )
My average idle is in the area 1000 RPMs ,on a tach ,based on wind speed down the runway ,on a given day( 1000 WB for little or no wind )
I do run 15% in all my glo engines , as well as my 51ST ,and it might be my K&B 1 L plug ( with an idle bar) that allows me to do that , not sure
It might also be that , that is what i broke the engine in on ,so the beak in is based upon the heat the 15% produces to seat the piston and linnner
i never change the nitro percentages i run in any glo engine ,as the heat produced by different percentages ,determines the clearences between the piston and cylinder wall
My 51 is a beast , with 61 power in a lighter engine
Do not run any motor larger than the 51 ,in a 40 size airframe
The down side , of to heavy an engine , is your inability to land as you should on final as the plane will drop out and stall from the nose weight ( overloading the wings lift ability,when in a glide )
60 size engines ,will not fly a 40 size airframe any better --overall -than a 46 or 51
I spent many hour trying to do that ,with less than good results
The bottom line is ,your final approach , touch down and bringing you plane to your feet ,is still one of the best parts of the flight ,and that enjoyment is lost with to much engine weight up front ,as you will be stuggling to control the plane when it is in that phase of the flight with the heavier nose weight
Just kills the final glide
Enjoy
One of my longest break in runs ,i can remember ,to get the engine to transition ,to get the NVs set correctly , on a bench
About a 1/2 gallon or so
Do realize during break in ,the cool down period between engine runs , is as important ,as running the engine itself
The engine must be completely cool ,at your next start up to evaluate your NV settings and see if they need adjustment ,again
If an engine starts to run hot and odd (because it was run lean) let the engine cool down completely ,then start it and reajust the Nvs
The pinch the tubing test, will run the engine up to max RPMS ,on the high and low speed NVS
Record the sound in your head and run the engine 2-300 off the max RPM ( SB 2-3 clicks richer ,than max RPM )
My average idle is in the area 1000 RPMs ,on a tach ,based on wind speed down the runway ,on a given day( 1000 WB for little or no wind )
I do run 15% in all my glo engines , as well as my 51ST ,and it might be my K&B 1 L plug ( with an idle bar) that allows me to do that , not sure
It might also be that , that is what i broke the engine in on ,so the beak in is based upon the heat the 15% produces to seat the piston and linnner
i never change the nitro percentages i run in any glo engine ,as the heat produced by different percentages ,determines the clearences between the piston and cylinder wall
My 51 is a beast , with 61 power in a lighter engine
Do not run any motor larger than the 51 ,in a 40 size airframe
The down side , of to heavy an engine , is your inability to land as you should on final as the plane will drop out and stall from the nose weight ( overloading the wings lift ability,when in a glide )
60 size engines ,will not fly a 40 size airframe any better --overall -than a 46 or 51
I spent many hour trying to do that ,with less than good results
The bottom line is ,your final approach , touch down and bringing you plane to your feet ,is still one of the best parts of the flight ,and that enjoyment is lost with to much engine weight up front ,as you will be stuggling to control the plane when it is in that phase of the flight with the heavier nose weight
Just kills the final glide
Enjoy
Last edited by tony0707; 01-14-2016 at 07:54 PM.
#1915
just buy a replacement carb hold down ,the nut and plastic piece that holds the carb snug ,in its place
You most likely could have strpped the old on with to much force
Your local hobby shop could have the part or tower hobby
You most likely could have strpped the old on with to much force
Your local hobby shop could have the part or tower hobby
#1917
I tried running a tank of 15% through my S90K in the fall and it crackled like no tomorrow. I stopped at a couple ounces and went to 5% and the crackle went away. I just stick to 5% most of the time; it's a safe bet - at least where I live. At higher elevations, the extra nitro helps with the lack of oxygen in the thinner air. I'll have to remember to keep that in mind when I give advice.
#1919
My Feedback: (2)
Join Date: Dec 2001
Location: Kerrville,
TX
Posts: 2,127
Likes: 0
Received 0 Likes
on
0 Posts
CR
Last edited by Charley; 01-15-2016 at 07:33 PM.
#1920
My smaller STs (.29, .51) throttled awesome on 5% - they even throttled nicely on straight fuel. The S90 was the picky one of the bunch. For the first few gallons, it needed the spraybar clocked 45* from straight in (fuel nipple pointed at rearmost hold of mount lug); after that third gallon of fuel or so, it was like a light switch went on and the engine ran horribly lean in the midrange. Reset the spraybar to straight in and it throttled like the .29 and .51 on the usual 5%/20% brew I used. Last summer I tried 10% in the .29 and it ran okay on it (on a full tuned pipe no less), the .51 & .45 may do fine on it as well, but the .90 will stay on 5%, especially with the new ring in it. When I was breaking in the .90 on the factory ring, it would barely tolerate 5% nitro. It seemed to be the pickiest of my Tigres.
#1921
Senior Member
Join Date: Apr 2005
Location: goolwasa, AUSTRALIA
Posts: 1,680
Likes: 0
Received 0 Likes
on
0 Posts
I know your ST are the Italian ones but my Chinese ones have only ever seen %10 nitro . They all ran fine from day one . I know this is of not much relevance to yours Tim and I dont really even know why I am writing this but what the heck it may interest somebody ! Cheers the pope
#1922
I know your ST are the Italian ones but my Chinese ones have only ever seen %10 nitro . They all ran fine from day one . I know this is of not much relevance to yours Tim and I dont really even know why I am writing this but what the heck it may interest somebody ! Cheers the pope
#1923
Would a Chinese ST with a good liner and a Bowman's ring still run well on 15% fuel?
#1924
I don't see why not. IMHO higher nitro just needs another head shim to lower the compression a bit so it does not preignite, or burn plugs. I think the Chinese ones are quite similar to the Italian ones. Just the machine operators sometimes let the form tools get a bit dull on the catseye in the carb. from what I heard.
#1925
Adding a shim may be necessary to use 15% on a regular basis. I would have a couple on hand just in case.
There are dimensional differences in some of the ST models made in China that were also made in Italy. Example is the G51. The bore of a Chinese G51 is slightly smaller than the Italian G51, so an Italian ring will either not fit or bind if used in a Chinese model. I'm sure there are others, but that's be one example Frank Bowman made me aware of when I picked up rings for my G51.
There are dimensional differences in some of the ST models made in China that were also made in Italy. Example is the G51. The bore of a Chinese G51 is slightly smaller than the Italian G51, so an Italian ring will either not fit or bind if used in a Chinese model. I'm sure there are others, but that's be one example Frank Bowman made me aware of when I picked up rings for my G51.