Tower .46 vs GMS .47
01-19-2010, 04:45 PM
#1
Tower .46 vs GMS .47
Hey guys,
I'm wondering if anyone can give me some in-depth info on these engines. I've read every forum I can on both engines that exist on the web by now I think!
Please don't recommend me an OS 46ax or 55ax, as I want to try a cheaper one for this project. I really love my OS 55ax turning 14,000rpm on 10%, but its $$. I'd really like to try either the Tower .46 or the GMS .47, and from all I've gathered they're almost exactly the same.
My question comes down to internals. I will be sealing both engines/carbs fully as I do with any engine. (I don't know why you wouldn't spend the 10 mins not to with any engine, but that's just me...). I plan on running these on either 5% homebrew or 0% FAI depending on what I can come up with. I'll be moving to a hotter plug and upping the compression to do so obviously.
Do both have removable head shims?
Is the compression similar on both?
RPM for XxX prop the same?
Same carbs?
Is one more reliable over the other?
Which would you choose?
One guy posted that the internals on the GMS are different, but he didn't elaborate... Could someone who knows their differences please post them?
I was debating going for the TT .46 PRO, but from all I've read the GMS/Tower engines will turn an easy 1500-2000 rpm on an 11x6 more than the TT will, even with the Tower .46 pipe on the TT. Yes the TT will probably be more reliable from the get go, but that's a moot point to me really, as I'll be sealing and drilling out the fuel inlet in the carb on the GMS if it's not aligned. I also plan on doing a little port work and clean-up on the sleeve as I do with most of my engines for a nice increase in power.
Thanks!
I'm wondering if anyone can give me some in-depth info on these engines. I've read every forum I can on both engines that exist on the web by now I think!
Please don't recommend me an OS 46ax or 55ax, as I want to try a cheaper one for this project. I really love my OS 55ax turning 14,000rpm on 10%, but its $$. I'd really like to try either the Tower .46 or the GMS .47, and from all I've gathered they're almost exactly the same.
My question comes down to internals. I will be sealing both engines/carbs fully as I do with any engine. (I don't know why you wouldn't spend the 10 mins not to with any engine, but that's just me...). I plan on running these on either 5% homebrew or 0% FAI depending on what I can come up with. I'll be moving to a hotter plug and upping the compression to do so obviously.
Do both have removable head shims?
Is the compression similar on both?
RPM for XxX prop the same?
Same carbs?
Is one more reliable over the other?
Which would you choose?
One guy posted that the internals on the GMS are different, but he didn't elaborate... Could someone who knows their differences please post them?
I was debating going for the TT .46 PRO, but from all I've read the GMS/Tower engines will turn an easy 1500-2000 rpm on an 11x6 more than the TT will, even with the Tower .46 pipe on the TT. Yes the TT will probably be more reliable from the get go, but that's a moot point to me really, as I'll be sealing and drilling out the fuel inlet in the carb on the GMS if it's not aligned. I also plan on doing a little port work and clean-up on the sleeve as I do with most of my engines for a nice increase in power.
Thanks!
01-19-2010, 05:20 PM
#2
RE: Tower .46 vs GMS .47
ORIGINAL: Eganwp
Hey guys,
I'm wondering if anyone can give me some in-depth info on these engines. I've read every forum I can on both engines that exist on the web by now I think!
Please don't recommend me an OS 46ax or 55ax, as I want to try a cheaper one for this project. I really love my OS 55ax turning 14,000rpm on 10%, but its $$. I'd really like to try either the Tower .46 or the GMS .47, and from all I've gathered they're almost exactly the same.
My question comes down to internals. I will be sealing both engines/carbs fully as I do with any engine. (I don't know why you wouldn't spend the 10 mins not to with any engine, but that's just me...). I plan on running these on either 5% homebrew or 0% FAI depending on what I can come up with. I'll be moving to a hotter plug and upping the compression to do so obviously.
Do both have removable head shims?
Is the compression similar on both?
RPM for XxX prop the same?
Same carbs?
Is one more reliable over the other?
Which would you choose?
One guy posted that the internals on the GMS are different, but he didn't elaborate... Could someone who knows their differences please post them?
I was debating going for the TT .46 PRO, but from all I've read the GMS/Tower engines will turn an easy 1500-2000 rpm on an 11x6 more than the TT will, even with the Tower .46 pipe on the TT. Yes the TT will probably be more reliable from the get go, but that's a moot point to me really, as I'll be sealing and drilling out the fuel inlet in the carb on the GMS if it's not aligned. I also plan on doing a little port work and clean-up on the sleeve as I do with most of my engines for a nice increase in power.
Thanks!
Hey guys,
I'm wondering if anyone can give me some in-depth info on these engines. I've read every forum I can on both engines that exist on the web by now I think!
Please don't recommend me an OS 46ax or 55ax, as I want to try a cheaper one for this project. I really love my OS 55ax turning 14,000rpm on 10%, but its $$. I'd really like to try either the Tower .46 or the GMS .47, and from all I've gathered they're almost exactly the same.
My question comes down to internals. I will be sealing both engines/carbs fully as I do with any engine. (I don't know why you wouldn't spend the 10 mins not to with any engine, but that's just me...). I plan on running these on either 5% homebrew or 0% FAI depending on what I can come up with. I'll be moving to a hotter plug and upping the compression to do so obviously.
Do both have removable head shims?
Is the compression similar on both?
RPM for XxX prop the same?
Same carbs?
Is one more reliable over the other?
Which would you choose?
One guy posted that the internals on the GMS are different, but he didn't elaborate... Could someone who knows their differences please post them?
I was debating going for the TT .46 PRO, but from all I've read the GMS/Tower engines will turn an easy 1500-2000 rpm on an 11x6 more than the TT will, even with the Tower .46 pipe on the TT. Yes the TT will probably be more reliable from the get go, but that's a moot point to me really, as I'll be sealing and drilling out the fuel inlet in the carb on the GMS if it's not aligned. I also plan on doing a little port work and clean-up on the sleeve as I do with most of my engines for a nice increase in power.
Thanks!
Otherwise, they are the same.
If one has a carb problem, the other has a carb problem.
These two engines are made in the same factory
01-19-2010, 07:22 PM
#3
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RE: Tower .46 vs GMS .47
Very good question and well put Eganwp! I too get frustrated when posting a simple question and everyone takes it to an area you DONT want 
I currently run the GMS 47, Remote Needle version, on the Hangar 9 P-51 PTS ARF. For me, this is the best engine on the market. I have been flying RC for 3 years now and even fly combat. The GMS is super reliable, starts every time, and has amazing power. Some people have issues with the carb bleeding air? They must not be pushing down on the carb seal when installing it to make a tight fit because my engine has no trouble shutting down. I first started out with an OS 46LA on the Mustang and boy did that engine cause me issues! It was un-reliable, slow, and hard to tune. I whole heartly believe in the GMS line and performance. The GMS gives me more power than you can believe and has an idle that will put anything to shame. I am currently building another plane and am actually in the same position, go with another GMS or go with the Tower. I would buy a GMS in a heartbeat but they are out everywhere. Tower says late Jan for re-stocking. SO, if you can, I would hold out for the GMS. But if your like me and you can see they are the same engine and that the tower is in stock, go for it. Hope this helps 
I currently run the GMS 47, Remote Needle version, on the Hangar 9 P-51 PTS ARF. For me, this is the best engine on the market. I have been flying RC for 3 years now and even fly combat. The GMS is super reliable, starts every time, and has amazing power. Some people have issues with the carb bleeding air? They must not be pushing down on the carb seal when installing it to make a tight fit because my engine has no trouble shutting down. I first started out with an OS 46LA on the Mustang and boy did that engine cause me issues! It was un-reliable, slow, and hard to tune. I whole heartly believe in the GMS line and performance. The GMS gives me more power than you can believe and has an idle that will put anything to shame. I am currently building another plane and am actually in the same position, go with another GMS or go with the Tower. I would buy a GMS in a heartbeat but they are out everywhere. Tower says late Jan for re-stocking. SO, if you can, I would hold out for the GMS. But if your like me and you can see they are the same engine and that the tower is in stock, go for it. Hope this helps
01-19-2010, 08:50 PM
#4
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RE: Tower .46 vs GMS .47
ORIGINAL: Eganwp
Hey guys,
I'm wondering if anyone can give me some in-depth info on these engines. I've read every forum I can on both engines that exist on the web by now I think!
Please don't recommend me an OS 46ax or 55ax, as I want to try a cheaper one for this project. I really love my OS 55ax turning 14,000rpm on 10%, but its $$. I'd really like to try either the Tower .46 or the GMS .47, and from all I've gathered they're almost exactly the same.
My question comes down to internals. I will be sealing both engines/carbs fully as I do with any engine. (I don't know why you wouldn't spend the 10 mins not to with any engine, but that's just me...). I plan on running these on either 5% homebrew or 0% FAI depending on what I can come up with. I'll be moving to a hotter plug and upping the compression to do so obviously.
Do both have removable head shims?
Is the compression similar on both?
RPM for XxX prop the same?
Same carbs?
Is one more reliable over the other?
Which would you choose?
One guy posted that the internals on the GMS are different, but he didn't elaborate... Could someone who knows their differences please post them?
I was debating going for the TT .46 PRO, but from all I've read the GMS/Tower engines will turn an easy 1500-2000 rpm on an 11x6 more than the TT will, even with the Tower .46 pipe on the TT. Yes the TT will probably be more reliable from the get go, but that's a moot point to me really, as I'll be sealing and drilling out the fuel inlet in the carb on the GMS if it's not aligned. I also plan on doing a little port work and clean-up on the sleeve as I do with most of my engines for a nice increase in power.
Thanks!
Hey guys,
I'm wondering if anyone can give me some in-depth info on these engines. I've read every forum I can on both engines that exist on the web by now I think!
Please don't recommend me an OS 46ax or 55ax, as I want to try a cheaper one for this project. I really love my OS 55ax turning 14,000rpm on 10%, but its $$. I'd really like to try either the Tower .46 or the GMS .47, and from all I've gathered they're almost exactly the same.
My question comes down to internals. I will be sealing both engines/carbs fully as I do with any engine. (I don't know why you wouldn't spend the 10 mins not to with any engine, but that's just me...). I plan on running these on either 5% homebrew or 0% FAI depending on what I can come up with. I'll be moving to a hotter plug and upping the compression to do so obviously.
Do both have removable head shims?
Is the compression similar on both?
RPM for XxX prop the same?
Same carbs?
Is one more reliable over the other?
Which would you choose?
One guy posted that the internals on the GMS are different, but he didn't elaborate... Could someone who knows their differences please post them?
I was debating going for the TT .46 PRO, but from all I've read the GMS/Tower engines will turn an easy 1500-2000 rpm on an 11x6 more than the TT will, even with the Tower .46 pipe on the TT. Yes the TT will probably be more reliable from the get go, but that's a moot point to me really, as I'll be sealing and drilling out the fuel inlet in the carb on the GMS if it's not aligned. I also plan on doing a little port work and clean-up on the sleeve as I do with most of my engines for a nice increase in power.
Thanks!
i took one head shim out of the gms (maybe both (their are 2) i dont remember) but it runs just fine, throttles the best of any two stroke engine i have and is very relieble. so reliable i switched from a ax55 to a gms.47 in a 3d plane
i have only used a tower .46 on a tower trainer it is just breakin in but isnt as reliable as the gms at this point in time (still new).
due to the price id go with the gms.47 its more reliable (during breakin) and is cheaper but you couldnt go wrong with either
01-19-2010, 09:03 PM
#5
RE: Tower .46 vs GMS .47
Thank you very much for your responses JJ and Stamey. That's exactly what I was looking for! This engine for the time being will actually being going on a H9 Mustang MKII for a semi-scale sport plane as well! I couldn't resist as I basically got the plane for free RTF after selling the dx6i. Selling the evolution .46 before i even run it, hence me looking for a cheap replacement.
I'll jump on the GMS .47 then and go with the remote needle valve to save my fingers from the inevitable tuning it that close WOT. Since I'm sealing it anyway, I doubt i'll have an issue with the remote valve.
Thanks for the RPM numbers as well. Exactly what I wanted to hear. You should try removing the other shim and going with an A3 plug. In theory if you can get the setup the same as the stock setup on 15%, you should be able to pull the same RPM #'s (+-200rpm most likely). Is you're idle okay, or do you run 3% acetone? I'm converting all my glow engines to FAI homebrew because I can get free methanol.
Thanks very much guys! <3
Selling the evolution .46 before i even run it, hence me looking for a cheap replacement.I'll jump on the GMS .47 then and go with the remote needle valve to save my fingers from the inevitable tuning it that close WOT. Since I'm sealing it anyway, I doubt i'll have an issue with the remote valve.
Thanks for the RPM numbers as well. Exactly what I wanted to hear. You should try removing the other shim and going with an A3 plug. In theory if you can get the setup the same as the stock setup on 15%, you should be able to pull the same RPM #'s (+-200rpm most likely). Is you're idle okay, or do you run 3% acetone? I'm converting all my glow engines to FAI homebrew because I can get free methanol.
Thanks very much guys! <3
01-19-2010, 09:53 PM
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RE: Tower .46 vs GMS .47
You already know all about the carb issues, good - sealing, and the often messed up fuel inlet. I think those are about the only negative issues I've ever heard of with them. The .32 I messed with runs like a bear, gobs of power, and I've heard the .47 pulls hard too but don't know it personally. I wouldn't hesitate to use the .32 or .47 if I got one cheap enough to excuse a bit of fiddling around with the carb. Sure, it shouldn't be like that, but if you know about it and don't mind fixing it.. well then off you go.
Based on the .32 experience, I have a feeling that the results individuals experience may depend - apart from the individual engine example - a bit on how fast they run the engine and thus the fuel flow requirements. Speculation.
MJD
Based on the .32 experience, I have a feeling that the results individuals experience may depend - apart from the individual engine example - a bit on how fast they run the engine and thus the fuel flow requirements. Speculation.
MJD
01-19-2010, 09:55 PM
#7
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RE: Tower .46 vs GMS .47
ORIGINAL: Eganwp
Thank you very much for your responses JJ and Stamey. That's exactly what I was looking for! This engine for the time being will actually being going on a H9 Mustang MKII for a semi-scale sport plane as well! I couldn't resist as I basically got the plane for free RTF after selling the dx6i. Selling the evolution .46 before i even run it, hence me looking for a cheap replacement.
I'll jump on the GMS .47 then and go with the remote needle valve to save my fingers from the inevitable tuning it that close WOT. Since I'm sealing it anyway, I doubt i'll have an issue with the remote valve.
Thanks for the RPM numbers as well. Exactly what I wanted to hear. You should try removing the other shim and going with an A3 plug. In theory if you can get the setup the same as the stock setup on 15%, you should be able to pull the same RPM #'s (+-200rpm most likely). Is you're idle okay, or do you run 3% acetone? I'm converting all my glow engines to FAI homebrew because I can get free methanol.
Thanks very much guys! <3
Thank you very much for your responses JJ and Stamey. That's exactly what I was looking for! This engine for the time being will actually being going on a H9 Mustang MKII for a semi-scale sport plane as well! I couldn't resist as I basically got the plane for free RTF after selling the dx6i.
Selling the evolution .46 before i even run it, hence me looking for a cheap replacement.I'll jump on the GMS .47 then and go with the remote needle valve to save my fingers from the inevitable tuning it that close WOT. Since I'm sealing it anyway, I doubt i'll have an issue with the remote valve.
Thanks for the RPM numbers as well. Exactly what I wanted to hear. You should try removing the other shim and going with an A3 plug. In theory if you can get the setup the same as the stock setup on 15%, you should be able to pull the same RPM #'s (+-200rpm most likely). Is you're idle okay, or do you run 3% acetone? I'm converting all my glow engines to FAI homebrew because I can get free methanol.
Thanks very much guys! <3
^^^ thats why im converting, i can get methanol for $3 a gallon and castor for $23 at sigmfg.com. shipping included on the castor, im mixing 18 gallons for about 6.75 a gallon, not bad at all.
im even running a magnum .52fs and its idle isnt terrible (its only have 1/8 gallon through it) at 3000 rpm on my homebrew toip end around 10000 on a 11x7. i think nitro is a little overrated
01-19-2010, 09:58 PM
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RE: Tower .46 vs GMS .47
Within this area, it brings to light a question from me. What is happening with GMS?? Tower is "sold out" of practically every GMS line 
Anyone know what is happening? Or is it just the end/begining of the year and all is being re-ordered? I would hate to see GMS go away, they have a huge following happening...
Anyone know what is happening? Or is it just the end/begining of the year and all is being re-ordered? I would hate to see GMS go away, they have a huge following happening...
01-19-2010, 10:16 PM
#9
RE: Tower .46 vs GMS .47
ORIGINAL: jimmyjames213
my engine runs no different on 0% nitro (no acetone) compared to 10% besides the rpm increase. the engine will idle all day long. dont be shooting for high rpm's/ good idle to start with let it breakin well, the engine really comes alive after a few gallons
^^^ thats why im converting, i can get methanol for $3 a gallon and castor for $23 at sigmfg.com. shipping included on the castor, im mixing 18 gallons for about 6.75 a gallon, not bad at all.
im even running a magnum .52fs and its idle isnt terrible (its only have 1/8 gallon through it) at 3000 rpm on my homebrew toip end around 10000 on a 11x7. i think nitro is a little overrated
ORIGINAL: Eganwp
Thank you very much for your responses JJ and Stamey. That's exactly what I was looking for! This engine for the time being will actually being going on a H9 Mustang MKII for a semi-scale sport plane as well! I couldn't resist as I basically got the plane for free RTF after selling the dx6i. Selling the evolution .46 before i even run it, hence me looking for a cheap replacement.
I'll jump on the GMS .47 then and go with the remote needle valve to save my fingers from the inevitable tuning it that close WOT. Since I'm sealing it anyway, I doubt i'll have an issue with the remote valve.
Thanks for the RPM numbers as well. Exactly what I wanted to hear. You should try removing the other shim and going with an A3 plug. In theory if you can get the setup the same as the stock setup on 15%, you should be able to pull the same RPM #'s (+-200rpm most likely). Is you're idle okay, or do you run 3% acetone? I'm converting all my glow engines to FAI homebrew because I can get free methanol.
Thanks very much guys! <3
Thank you very much for your responses JJ and Stamey. That's exactly what I was looking for! This engine for the time being will actually being going on a H9 Mustang MKII for a semi-scale sport plane as well! I couldn't resist as I basically got the plane for free RTF after selling the dx6i.
Selling the evolution .46 before i even run it, hence me looking for a cheap replacement.I'll jump on the GMS .47 then and go with the remote needle valve to save my fingers from the inevitable tuning it that close WOT. Since I'm sealing it anyway, I doubt i'll have an issue with the remote valve.
Thanks for the RPM numbers as well. Exactly what I wanted to hear. You should try removing the other shim and going with an A3 plug. In theory if you can get the setup the same as the stock setup on 15%, you should be able to pull the same RPM #'s (+-200rpm most likely). Is you're idle okay, or do you run 3% acetone? I'm converting all my glow engines to FAI homebrew because I can get free methanol.
Thanks very much guys! <3
^^^ thats why im converting, i can get methanol for $3 a gallon and castor for $23 at sigmfg.com. shipping included on the castor, im mixing 18 gallons for about 6.75 a gallon, not bad at all.
im even running a magnum .52fs and its idle isnt terrible (its only have 1/8 gallon through it) at 3000 rpm on my homebrew toip end around 10000 on a 11x7. i think nitro is a little overrated
Nitro is nice to have, but I am in the same boat as you are. I can buy Methanol for $2.75 a gallon 2 miles from my house straight out of the pump (Late Model Stock car racing).
I do have some Nitro too, since I have a guy a few miles away who race's a Nitro Injected Harley.
01-19-2010, 10:20 PM
#10
RE: Tower .46 vs GMS .47
ORIGINAL: Stamey
Within this area, it brings to light a question from me. What is happening with GMS?? Tower is ''sold out'' of practically every GMS line Anyone know what is happening? Or is it just the end/begining of the year and all is being re-ordered? I would hate to see GMS go away, they have a huge following happening...
Within this area, it brings to light a question from me. What is happening with GMS?? Tower is ''sold out'' of practically every GMS line
Anyone know what is happening? Or is it just the end/begining of the year and all is being re-ordered? I would hate to see GMS go away, they have a huge following happening...
That is just Towers Marketing crap. The Tower .75 was back ordered for more than a year, and then came back. Now it is back ordered again, and they just keep pushing the date back. My friend has two .75's on back order for months, and Tower suggested in a email that He purchase the OS .75AX instead.[X(] He told them he will stay on the back order list.
01-19-2010, 11:10 PM
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RE: Tower .46 vs GMS .47
from my understanding this happens every year (happened last year) so i wouldnt worry about it.
nitro isnt bad, just expensive. once you see how your engines run on 0% you may not go back. what oil are you planning to use? im looking to see if i can get some synthetics for cheap to run in my 4 strokes so i dont have to clean them as often, but if its doubble the price of castor i will clean away
nitro isnt bad, just expensive. once you see how your engines run on 0% you may not go back. what oil are you planning to use? im looking to see if i can get some synthetics for cheap to run in my 4 strokes so i dont have to clean them as often, but if its doubble the price of castor i will clean away
01-19-2010, 11:58 PM
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RE: Tower .46 vs GMS .47
ORIGINAL: jimmyjames213
my engine runs no different on 0% nitro (no acetone) compared to 10% besides the rpm increase. the engine will idle all day long. dont be shooting for high rpm's/ good idle to start with let it breakin well, the engine really comes alive after a few gallons
^^^ thats why im converting, i can get methanol for $3 a gallon and castor for $23 at sigmfg.com. shipping included on the castor, im mixing 18 gallons for about 6.75 a gallon, not bad at all.
im even running a magnum .52fs and its idle isnt terrible (its only have 1/8 gallon through it) at 3000 rpm on my homebrew toip end around 10000 on a 11x7. i think nitro is a little overrated
my engine runs no different on 0% nitro (no acetone) compared to 10% besides the rpm increase. the engine will idle all day long. dont be shooting for high rpm's/ good idle to start with let it breakin well, the engine really comes alive after a few gallons
^^^ thats why im converting, i can get methanol for $3 a gallon and castor for $23 at sigmfg.com. shipping included on the castor, im mixing 18 gallons for about 6.75 a gallon, not bad at all.
im even running a magnum .52fs and its idle isnt terrible (its only have 1/8 gallon through it) at 3000 rpm on my homebrew toip end around 10000 on a 11x7. i think nitro is a little overrated
MJD
01-20-2010, 12:09 AM
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RE: Tower .46 vs GMS .47
When you get the GMS 47 take the carb nipple out and inspect if the inlet is obstructed by a missaligned brass spraybar insert...that caused lots of problems and if it is missaligned, put the nipple again and re-drill it.
01-20-2010, 12:17 AM
#14
RE: Tower .46 vs GMS .47
Yea I can't wait to get away from paying rediculous LHS prices on fuel. It's now $30 a gallon for 10% Omega here!!! :< With free methanol, I'll be running klotz synthetic at 80%, 20% BeNol castor for a 17% or 18% total oil mix. I'll test out 0 acetone, 3% acetone and also try diluting down a jug of 30 or 40% nitro RC truggy fuel among 6 gallons or so if I can't get all my engines to run good on 0%. This is of course after head shimming and hot plugging all of them.
After that I plan on porting the rest of my engines (I don't have too many yet) and grab another couple hundred rpm. I have a TT .28 truggy engine (before I bought and modded my picco .28) that port/polish and timing changes REALLY woke the thing up. I'm hoping some of my plane engines respond the same. I really like tinkering with engines and this kind of stuff. It always gets me excited, lol. My OS 55ax already had a pretty well finished porting job from the factory so I doubt I'll gain a whole lot without really overhauling the timing on it which I probably wont do. I'm excited to tear down this GMS and after a full break-in see what she'll pull. Nice thing is, I can get a new GMS .47 that's in stock here at an LHS for $75, so I'll probably grab one this week.
I'll let you know the results once i get everything up and running. WAY too many planes on the go for spring though! haha. Thanks for all the responses too guys.
After that I plan on porting the rest of my engines (I don't have too many yet) and grab another couple hundred rpm. I have a TT .28 truggy engine (before I bought and modded my picco .28) that port/polish and timing changes REALLY woke the thing up. I'm hoping some of my plane engines respond the same. I really like tinkering with engines and this kind of stuff. It always gets me excited, lol. My OS 55ax already had a pretty well finished porting job from the factory so I doubt I'll gain a whole lot without really overhauling the timing on it which I probably wont do. I'm excited to tear down this GMS and after a full break-in see what she'll pull. Nice thing is, I can get a new GMS .47 that's in stock here at an LHS for $75, so I'll probably grab one this week.
I'll let you know the results once i get everything up and running. WAY too many planes on the go for spring though! haha. Thanks for all the responses too guys.
01-20-2010, 12:20 AM
#15
RE: Tower .46 vs GMS .47
ORIGINAL: estradajae
When you get the GMS 47 take the carb nipple out and inspect if the inlet is obstructed by a missaligned brass spraybar insert...that caused lots of problems and if it is missaligned, put the nipple again and re-drill it.
When you get the GMS 47 take the carb nipple out and inspect if the inlet is obstructed by a missaligned brass spraybar insert...that caused lots of problems and if it is missaligned, put the nipple again and re-drill it.
What interests me is the fact that I seem to never hear anyone complain of this problem on the Tower .46, which partially spurred my reason for posting this thread. The factories QA must differ between the two, because I sure can't see Tower doin their own QA, but who knows!
01-20-2010, 12:25 AM
#16
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RE: Tower .46 vs GMS .47
I really don't know, but if I don't remember right, the tower 46 had also reliability problems...maybe the same issue? I don't know...
About FAI fuel..what can i say, I have a tower 75, took off the thick shim, and the thing turns a master scimitar 12x6 around 14600RPMs.
About FAI fuel..what can i say, I have a tower 75, took off the thick shim, and the thing turns a master scimitar 12x6 around 14600RPMs.
01-20-2010, 12:34 AM
#17
RE: Tower .46 vs GMS .47
Nice!!! That's actually the next engine I was planning on buying to test out on FAI. That's pretty good rpm! Only problem is, I've been trying to "order" one from tower since last July... They've been backordered for the past 6 months yet again...
01-20-2010, 02:13 AM
#18
Senior Member
My Feedback: (14)
RE: Tower .46 vs GMS .47
ORIGINAL: Eganwp
Yea I can't wait to get away from paying rediculous LHS prices on fuel. It's now $30 a gallon for 10% Omega here!!! :< With free methanol, I'll be running klotz synthetic at 80%, 20% BeNol castor for a 17% or 18% total oil mix. I'll test out 0 acetone, 3% acetone and also try diluting down a jug of 30 or 40% nitro RC truggy fuel among 6 gallons or so if I can't get all my engines to run good on 0%. This is of course after head shimming and hot plugging all of them.
After that I plan on porting the rest of my engines (I don't have too many yet) and grab another couple hundred rpm. I have a TT .28 truggy engine (before I bought and modded my picco .28) that port/polish and timing changes REALLY woke the thing up. I'm hoping some of my plane engines respond the same. I really like tinkering with engines and this kind of stuff. It always gets me excited, lol. My OS 55ax already had a pretty well finished porting job from the factory so I doubt I'll gain a whole lot without really overhauling the timing on it which I probably wont do. I'm excited to tear down this GMS and after a full break-in see what she'll pull. Nice thing is, I can get a new GMS .47 that's in stock here at an LHS for $75, so I'll probably grab one this week.
I'll let you know the results once i get everything up and running. WAY too many planes on the go for spring though! haha. Thanks for all the responses too guys.
Yea I can't wait to get away from paying rediculous LHS prices on fuel. It's now $30 a gallon for 10% Omega here!!! :< With free methanol, I'll be running klotz synthetic at 80%, 20% BeNol castor for a 17% or 18% total oil mix. I'll test out 0 acetone, 3% acetone and also try diluting down a jug of 30 or 40% nitro RC truggy fuel among 6 gallons or so if I can't get all my engines to run good on 0%. This is of course after head shimming and hot plugging all of them.
After that I plan on porting the rest of my engines (I don't have too many yet) and grab another couple hundred rpm. I have a TT .28 truggy engine (before I bought and modded my picco .28) that port/polish and timing changes REALLY woke the thing up. I'm hoping some of my plane engines respond the same. I really like tinkering with engines and this kind of stuff. It always gets me excited, lol. My OS 55ax already had a pretty well finished porting job from the factory so I doubt I'll gain a whole lot without really overhauling the timing on it which I probably wont do. I'm excited to tear down this GMS and after a full break-in see what she'll pull. Nice thing is, I can get a new GMS .47 that's in stock here at an LHS for $75, so I'll probably grab one this week.
I'll let you know the results once i get everything up and running. WAY too many planes on the go for spring though! haha. Thanks for all the responses too guys.
I wish I could be there, silently in the background, to watch you and your friends "hot plugging" an airplane engine, and I don't mean that in a mean sense. I'd like to see you and your friends' expressions and hear your comments while you figure out what is going on. I miss that part of modeling - a lot (being young and figuring things out, that is).
Ed Cregger
01-20-2010, 02:14 AM
#19
Senior Member
RE: Tower .46 vs GMS .47
Eganwp.
You sound like a man who knows a thing or two about engines and should have no problems handling a Magnum/ASP XLS .52.
Seal it up and you have a reliable great runner that is much more powerfull than those GMS/Tower 46`s GUARANTEED. The XLS is one of the absolutely most powerfull "standard" engines out there and it is cheaper than the GMS too. (from Hong Kong at least)
It weighs in at the same weight, same physical size and you can order it today, not in months
Since you like to do a little work on them (like myself) you can get some incredible results with the XLS, mine turns APC 12-4 at 15000 rpm static (mousse can, port work, headshims) Your 11-6 would be about the same
You sound like a man who knows a thing or two about engines and should have no problems handling a Magnum/ASP XLS .52.
Seal it up and you have a reliable great runner that is much more powerfull than those GMS/Tower 46`s GUARANTEED. The XLS is one of the absolutely most powerfull "standard" engines out there and it is cheaper than the GMS too. (from Hong Kong at least)
It weighs in at the same weight, same physical size and you can order it today, not in months
Since you like to do a little work on them (like myself) you can get some incredible results with the XLS, mine turns APC 12-4 at 15000 rpm static (mousse can, port work, headshims) Your 11-6 would be about the same
01-20-2010, 02:16 AM
#20
Senior Member
My Feedback: (14)
RE: Tower .46 vs GMS .47
I would like to put Magnum's .52 two-stroke up against the Tower and GMS .46/.47 engines, performance and tractability wise. I'll bet the Sanye (Magnum/ASP) would come out on top, especially regarding the need for sealing everything up. Although, like the one gentleman stated, sealing up an engine is automatic for me these days, regardless of its brand.
Ed Cregger
Ed Cregger
01-20-2010, 02:19 AM
#21
My Feedback: (1)
RE: Tower .46 vs GMS .47
I bought my first GMS about a year ago and now I have three of the 47'S and three of the 61'S and they are my small glow engine of choice now! Can not be fair to tower because do not own one yet to say, But will try one soon, more the likely the 75!
01-20-2010, 02:41 AM
#23
Senior Member
RE: Tower .46 vs GMS .47
I use high temp silicone , the red stuff (RTV).
I use a little around the carb before I insert it into the case and a little around the back plate before I put it back on. I do this on all my engines just to be sure
I use a little around the carb before I insert it into the case and a little around the back plate before I put it back on. I do this on all my engines just to be sure
01-20-2010, 07:50 AM
#24
RE: Tower .46 vs GMS .47
I use Yamabond, made by Yamaha motorcycles . It's different the RTV, Has more body, adheres better to the surface and does not crumble or flake off like RTV and cost about the same. And if you let it set up a little ,before you install the part, it makes it's own gasket . Hope the pic's show what I'm trying to say.
01-20-2010, 08:19 AM
#25
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RE: Tower .46 vs GMS .47
ORIGINAL: Eganwp
Yea I can't wait to get away from paying rediculous LHS prices on fuel. It's now $30 a gallon for 10% Omega here!!! :<
Yea I can't wait to get away from paying rediculous LHS prices on fuel. It's now $30 a gallon for 10% Omega here!!! :<