o.s. 1.08 need higer rpms
10-24-2008, 10:18 AM
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o.s. 1.08 need higer rpms
Hey guys.
Here is my situation. i have a 1.08 BX-1 from OS and have it on an RCairboat called the Hull Force. You should be able to find the thread in the rcairboat section with little problems, its right at the top. the boat weighs right at around 12 pounds with a full tank of fuel. I am going to make some alterations to take a little weight off to start.
Anywho, here's the issue.
I had the motor tached the other day at the pond at full throttle, it was 8800 rpms with a 14x8 master airscrew plastic prop. I am also running the stock muffler. now that may be great for an aircraft but with these airboats I am looking for a much higher RMP out of it to get top speed. The specs say the motor gets 3HP at 16000 rpms. Now i am looking to get close to 10500 or 11,000 out of it, or higher!
A. do any of you think that is possible?
B. what type of propeller would get me there? 13x8 12x10? or something else?
C. the motor can be run to 20% nitro, but i am running 10-15% nitro. will a higher nitro have any significant increase in the performance of the engine?
D. Would an aftermarket Carb be a good option for me? and if so, where do i find such a carburetor.
thanks!
-MJ
Here is my situation. i have a 1.08 BX-1 from OS and have it on an RCairboat called the Hull Force. You should be able to find the thread in the rcairboat section with little problems, its right at the top. the boat weighs right at around 12 pounds with a full tank of fuel. I am going to make some alterations to take a little weight off to start.
Anywho, here's the issue.
I had the motor tached the other day at the pond at full throttle, it was 8800 rpms with a 14x8 master airscrew plastic prop. I am also running the stock muffler. now that may be great for an aircraft but with these airboats I am looking for a much higher RMP out of it to get top speed. The specs say the motor gets 3HP at 16000 rpms. Now i am looking to get close to 10500 or 11,000 out of it, or higher!
A. do any of you think that is possible?
B. what type of propeller would get me there? 13x8 12x10? or something else?
C. the motor can be run to 20% nitro, but i am running 10-15% nitro. will a higher nitro have any significant increase in the performance of the engine?
D. Would an aftermarket Carb be a good option for me? and if so, where do i find such a carburetor.
thanks!
-MJ
10-24-2008, 11:06 AM
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RE: o.s. 1.08 need higer rpms
your engine has one of the best glow carbs ever made by OS engines. Dont change it!
You dont need more nitro, 10-15% is all this engine needs.
Just use a smaller propeller to gain more RPM dont worry you wont damage the engine.
use APC 12x10 or 12x12 propeller and throttle away.
You dont need more nitro, 10-15% is all this engine needs.
Just use a smaller propeller to gain more RPM dont worry you wont damage the engine.
use APC 12x10 or 12x12 propeller and throttle away.
10-24-2008, 12:15 PM
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RE: o.s. 1.08 need higer rpms
nice to know. thanks man.
i guess thats why it says it will swing up to a 18-6 in the specs.
heres my next question, is there a motor around that size that will move higher spms?
i guess thats why it says it will swing up to a 18-6 in the specs.
heres my next question, is there a motor around that size that will move higher spms?
10-24-2008, 12:46 PM
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RE: o.s. 1.08 need higer rpms
heres my next question, is there a motor around that size that will move higher spms?
10-24-2008, 01:14 PM
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RE: o.s. 1.08 need higer rpms
Hi!
First of all! The MA prop is the worst prop to choose if you want performance.It's noisy and don't perform the way an APC or RAM prop does.
10% nitro is just fine. I would try a 12x10, 12x12 " APC prop and a tuned pipe. The tuned pipe will raise power 10-15%.
The OS carb is the best carb there is!
First of all! The MA prop is the worst prop to choose if you want performance.It's noisy and don't perform the way an APC or RAM prop does.
10% nitro is just fine. I would try a 12x10, 12x12 " APC prop and a tuned pipe. The tuned pipe will raise power 10-15%.
The OS carb is the best carb there is!
10-24-2008, 01:31 PM
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RE: o.s. 1.08 need higer rpms
okay, you think some 12 and 13" inch props would do the trick on this? because i am in position to go buying a new engine, but some nice props might help.
anyone got some used ones they dont need anymore!
anyone got some used ones they dont need anymore!
10-24-2008, 01:56 PM
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RE: o.s. 1.08 need higer rpms
The OS7D carb. and the OS108FSR is one of the absolute best twostroke engines ever made. If you need more rpm then put a smaller size prop on it and try out. If you need a whole lot more power the a tuned pipe will do the trick. You should then be able to peak around 12000rpm with an apc 12x12 or 13x10.
10-24-2008, 02:05 PM
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RE: o.s. 1.08 need higer rpms
you all have been VERY helpful... I will be testing some props this weekend in order to see what i can come up with for a better rpm reading.
ill try to get some video of the engine running with different props for you to listen to.
but here is one wit the 15x8 before it even hit the water.
http://s63.photobucket.com/albums/h1...t=MVI_3118.flv
http://s63.photobucket.com/albums/h1...t=MVI_3116.flv
ill try to get some video of the engine running with different props for you to listen to.
but here is one wit the 15x8 before it even hit the water.
http://s63.photobucket.com/albums/h1...t=MVI_3118.flv
http://s63.photobucket.com/albums/h1...t=MVI_3116.flv
10-25-2008, 08:41 PM
#10
RE: o.s. 1.08 need higer rpms
ORIGINAL: mjderstine
Hey guys.
Here is my situation. i have a 1.08 BX-1 from OS and have it on an RCairboat called the Hull Force. You should be able to find the thread in the rcairboat section with little problems, its right at the top. the boat weighs right at around 12 pounds with a full tank of fuel. I am going to make some alterations to take a little weight off to start.
Anywho, here's the issue.
I had the motor tached the other day at the pond at full throttle, it was 8800 rpms with a 14x8 master airscrew plastic prop. I am also running the stock muffler. now that may be great for an aircraft but with these airboats I am looking for a much higher RMP out of it to get top speed. The specs say the motor gets 3HP at 16000 rpms. Now i am looking to get close to 10500 or 11,000 out of it, or higher!
A. do any of you think that is possible?
B. what type of propeller would get me there? 13x8 12x10? or something else?
C. the motor can be run to 20% nitro, but i am running 10-15% nitro. will a higher nitro have any significant increase in the performance of the engine?
D. Would an aftermarket Carb be a good option for me? and if so, where do i find such a carburetor.
thanks!
-MJ
Hey guys.
Here is my situation. i have a 1.08 BX-1 from OS and have it on an RCairboat called the Hull Force. You should be able to find the thread in the rcairboat section with little problems, its right at the top. the boat weighs right at around 12 pounds with a full tank of fuel. I am going to make some alterations to take a little weight off to start.
Anywho, here's the issue.
I had the motor tached the other day at the pond at full throttle, it was 8800 rpms with a 14x8 master airscrew plastic prop. I am also running the stock muffler. now that may be great for an aircraft but with these airboats I am looking for a much higher RMP out of it to get top speed. The specs say the motor gets 3HP at 16000 rpms. Now i am looking to get close to 10500 or 11,000 out of it, or higher!
A. do any of you think that is possible?
B. what type of propeller would get me there? 13x8 12x10? or something else?
C. the motor can be run to 20% nitro, but i am running 10-15% nitro. will a higher nitro have any significant increase in the performance of the engine?
D. Would an aftermarket Carb be a good option for me? and if so, where do i find such a carburetor.
thanks!
-MJ
10-26-2008, 03:49 AM
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RE: o.s. 1.08 need higer rpms
A friend of mine has bought a used one.It seems brand new,opens up after every run.
He has 11500 RPM(max.) with 14-6 prop,5% nitro-castor fuel.Using OS A5 plug( only plug we could make it run flawless,other plugs didnt work at all)
He has 11500 RPM(max.) with 14-6 prop,5% nitro-castor fuel.Using OS A5 plug( only plug we could make it run flawless,other plugs didnt work at all)
10-27-2008, 07:16 AM
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RE: o.s. 1.08 need higer rpms
cyclic:
what do you mean by kind of clearance? from the prop to the hull of the boat? its about 1/2 inch with a 15" prop, and you can do the math for any other prop clearance.
Turk1:
i still have the stock plug in mine. I have heard that the a5 is a good choice to use in there. I will do some tests on a different prop this weekend.
Kweasel:
the tank is behind the engine. the top level of the tank is just below the level of the carb. I was told that if the level of the tank was any higher fuel would start flowing directly into the carb and flood the engine.
sounds like i have some work to do to the engine really working. what size fuel line are you all running. I am using medium size.
what do you mean by kind of clearance? from the prop to the hull of the boat? its about 1/2 inch with a 15" prop, and you can do the math for any other prop clearance.
Turk1:
i still have the stock plug in mine. I have heard that the a5 is a good choice to use in there. I will do some tests on a different prop this weekend.
Kweasel:
the tank is behind the engine. the top level of the tank is just below the level of the carb. I was told that if the level of the tank was any higher fuel would start flowing directly into the carb and flood the engine.
sounds like i have some work to do to the engine really working. what size fuel line are you all running. I am using medium size.
10-27-2008, 08:16 AM
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RE: o.s. 1.08 need higer rpms
I use a OSF glowplug in my 108 and it works really nice too.
In an RC/airboat you dont need to worry about tank level as much as in an airplane.
In an RC/airboat you dont need to worry about tank level as much as in an airplane.
