30% nitro fuel
02-17-2014 | 12:26 PM
#1
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30% nitro fuel
Okay so I had purchased a used savage xl and had to replace the engine on it. I have a gallon of odonnell 20% r2r nitro and a gallon of Byron's gen2 30% nitro fuel. I broke the engine in with the 20% from odonnell and now that's it's almost all gone was wondering if it is bad to switch to the other fuel or even jump up to that % of nitro. I've heard so much back and forth from people I would like a good solid answer from a expert. Would it be best to just stick to the odonnell it's whole life or can I switch up what fuel I run?
02-17-2014 | 12:28 PM
#2
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I am not sure about switching but I know if you are going to run 30% that you will want to add a shim between the head and the block to lower compression and probably run a bit cooler of a plug to keep things running optimally.
02-17-2014 | 12:37 PM
#4
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It's also about 20 degrees here and I can't seem to get this thing to run at the right temp while I lean the hsp. It will over heat every time and won't ever even shift before it gets too hot and I have to kill it. I was running it on dry tar in 20 degree weather and it was getting hot so I'm kinda worried in the summer time it will get really hot! I want it to be fast and run the right temps but can't seem to figure it out and everytime I start from factory setting and try and take it from there but not really any luck
02-17-2014 | 02:01 PM
#5
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Joined: Nov 2008
Posts: 172
While it's suggested to stick with a particular nitro concentration throughout the life of an engine, it won't burn to the ground if you decide to change it up. The only concern I personally would have is going up to such a high nitro concentration - 30% is pretty high, given sport fuels with high oil contents can go as low as 10%, and I've never considered going above 20%. And if I'm correct, the Byron Gen2 fuel is a race fuel, so it likely has a lower oil content than comparable sport fuels.
So, first, exercise some caution and be conservative when re-tuning the engine; perhaps run a little richer than you normally might for the first few tanks while you and the engine adjust.
Second, you'll want to watch the glow plug. If it were me, I'd swap in a new plug identical to what you're using now, run it for a couple tanks, then see how it looks. From Ron Paris:
Adjust accordingly, and enjoy the power!
So, first, exercise some caution and be conservative when re-tuning the engine; perhaps run a little richer than you normally might for the first few tanks while you and the engine adjust.
Second, you'll want to watch the glow plug. If it were me, I'd swap in a new plug identical to what you're using now, run it for a couple tanks, then see how it looks. From Ron Paris:
Originally Posted by Ron Paris
How to “READ” your glow plug:
OS and Turbo glow plugs go gray sooner [easier] than McCoy plugs; this is not necessarily bad. Actually when A new plug wire just goes slightly gray after a 5 or 10 minute hard run it means your very close to an optimal horsepower tune, but be careful the next step is TOO LEAN!
My rule of thumb.
1} Wire and surrounding bottom of plug wet, with like new shiny wire = rich side of optimum power 85%
2} Wire and surrounding bottom of plug starting to dry and wire starting to gray = Very close to optimum power 95%
3} Wire and surrounding bottom of plug dry, wire totally gray but not distorted optimum power 100%
4} Wire and surrounding bottom of plug dry, wire distorted = slightly lean DANGER!
5} Wire and surrounding bottom of plug dry, wire broken and distorted or burnt up = extremely lean possible engine damage!
Note: You can only “Read” your plug in a nearly new state [Wire like new and shiny] A gray plug can still operate well. After it has totally gone gray,
performance can start to fall off. To test just put in a new plug and if there is no difference in performance save the gray one or put it back in. If your engine does not feel or run right try a new plug before making major tune changes
OS and Turbo glow plugs go gray sooner [easier] than McCoy plugs; this is not necessarily bad. Actually when A new plug wire just goes slightly gray after a 5 or 10 minute hard run it means your very close to an optimal horsepower tune, but be careful the next step is TOO LEAN!
My rule of thumb.
1} Wire and surrounding bottom of plug wet, with like new shiny wire = rich side of optimum power 85%
2} Wire and surrounding bottom of plug starting to dry and wire starting to gray = Very close to optimum power 95%
3} Wire and surrounding bottom of plug dry, wire totally gray but not distorted optimum power 100%
4} Wire and surrounding bottom of plug dry, wire distorted = slightly lean DANGER!
5} Wire and surrounding bottom of plug dry, wire broken and distorted or burnt up = extremely lean possible engine damage!
Note: You can only “Read” your plug in a nearly new state [Wire like new and shiny] A gray plug can still operate well. After it has totally gone gray,
performance can start to fall off. To test just put in a new plug and if there is no difference in performance save the gray one or put it back in. If your engine does not feel or run right try a new plug before making major tune changes
02-17-2014 | 02:48 PM
#6
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My reasoning for stepping down on the coolness of the plug is that the higher nitro percentage burns easier and the higher nitro content is harder to tune, colder plugs help widen the tuning window. What is posted above is good info. Weather does affect plugs but I cant really tell you where to start. You will just have to buy a few different temp plugs and try them back to back. Cooler plugs are thicker so they are a little more durable.
Since I have steped up to 30%, I will never go back! The power and response is just sick, even when adding a shim to the head. I havent really had any failures caused by the lower oil content. As long as you keep the tune on spot. The higher % nitro will narrow the tuning window so you will have to learn to pay closer attention to how the engine is running.
This comes direct from RB products.
To be able to adjust the carburetor of a nitro engine correctly, you need patience and must try and understand how this works. Sometimes nitro engines are difficult to set, and if you have difficulties, then we suggest you ask your LHS (Local Hobby Shop) or Dealer where you have purchased the engine to help you in this matter. If however you prefer to try yourself, here is how:
Attention: Work only on 1 carburetor adjustment at a time and make only small adjustments, maximum 1/8 of a turn! Pre adjustments.
Once the engine is started let it reach operating temperature, then proceed as follows:
Set the main needle by holding the car off the ground, then open throttle completely. The engine should not completely clean out and should stabilize at 80% of top RPM, but if the engine cleans out completely and the rpm continues to climb too high, close the throttle immediately and open the main needle and repeat the sequence, until the engine does not clean out completely and the rpm stabilizes at 80%. If the engine runs too rich (4-stroking aIl the way), lean the main needle until the engine just starts to clean out.
Set the idle rpm of the engine by holding the car off the ground, then open throttle till the engine rpm reaches the above rpm, and then close the throttle. If the engine stalls, then you need to increase the idle by turning the idle air screw clockwise until the engine does not stall anymore. However, when the idle of the engine remains too high, then you need to lower the idle rpm by turning the idle air screw counter clockwise.
Set the idle needle by holding the car off the ground, open the throttle until the engine reaches the 80% rpm, and then close the throttle. If the engine idles for 2-5 seconds and the idle rpm decreases, then the idle needle is set too rich, so lean this setting by turning the idle needle clockwise. Repeat this process until the engine has a constant rpm for at least 20-30 seconds after the throttle has been closed. If the engine idles for 2-5 seconds and then the idle rpm increases, the engine is running too Iean at the idle needle, so richen the idle needle by turning it counter clockwise to remedy this.
Set the idle rpm by using the idle air screw, and try to find a low but reliable idle rpm. A too high idle rpm makes it more difficult to slow the car during breaking.
Attention: When adjusting the idle needle, this then can effect the idle rpm, use the idle air screw to adjust the low rpm when it becomes too high or too low.
Once you are satisfied with your carburetor settings you are ready to put the car on the track and make the final adjustments.
· Final adjustments while driving.
When ready with the pre adjustments you are now ready to put the car on the track and start your final adjustments. If you have set your idle needle and idle rpm correctly in the pre adjustment phase then you only need to adjust the main needle to find the correct setting and performances of your engine.
Start leaning the main needle by small increments (1/8 of a turn maximum) and run the car again, repeating this sequence until the engine completely cleans out, accelerates well and reaches maximum speed.
To prevent your engine from running too hot, it is advised then to richen the main needle (1/8 of a turn counter-clockwise), since running the engine too lean on the main needle will cause the engine to overheat, resulting in excessive engine wear and possible breakage.
A possible way to check the engine temperature is to apply a few drops of water on the cylinder head. The drops should evaporate only after 3-5 seconds, If they evaporate immediately the engine is too hot, so richen the main needle (1/4 of a turn counter-clockwise) immediately.
Check your engine temperature regularly. Another way of knowing if your engine is running too lean, is when you are driving and the engine starts too loose its power at the low rpm range and no smoke is coming from the exhaust; if this happens, richen the main-needle if you do not want to damage the engine.
Once properly adjusted, the engine should produce a strong, high-pitched sound at maximum speed, and a thin trail of smoke should be visible from the exhaust tailpipe.
NOTE: The carburetor settings may change with changes in weather conditions, fuel, glow plug or exhaust system. After changing any of these, always richen the main needle ¼ to ½ of a turn and then re-adjust the main needle again on the track.
NOTE: When the engine stops, the heat of the engine will go into the carburetor and alter the idle rpm. This can translate into a bad idle rpm, especially when you have your idle rpm a little low. This will come back to normal when you have made at least 1 lap on the track again so the carburetor has reached its normal working temperature.
Since I have steped up to 30%, I will never go back! The power and response is just sick, even when adding a shim to the head. I havent really had any failures caused by the lower oil content. As long as you keep the tune on spot. The higher % nitro will narrow the tuning window so you will have to learn to pay closer attention to how the engine is running.
This comes direct from RB products.
To be able to adjust the carburetor of a nitro engine correctly, you need patience and must try and understand how this works. Sometimes nitro engines are difficult to set, and if you have difficulties, then we suggest you ask your LHS (Local Hobby Shop) or Dealer where you have purchased the engine to help you in this matter. If however you prefer to try yourself, here is how:
Attention: Work only on 1 carburetor adjustment at a time and make only small adjustments, maximum 1/8 of a turn! Pre adjustments.
Once the engine is started let it reach operating temperature, then proceed as follows:
Set the main needle by holding the car off the ground, then open throttle completely. The engine should not completely clean out and should stabilize at 80% of top RPM, but if the engine cleans out completely and the rpm continues to climb too high, close the throttle immediately and open the main needle and repeat the sequence, until the engine does not clean out completely and the rpm stabilizes at 80%. If the engine runs too rich (4-stroking aIl the way), lean the main needle until the engine just starts to clean out.
Set the idle rpm of the engine by holding the car off the ground, then open throttle till the engine rpm reaches the above rpm, and then close the throttle. If the engine stalls, then you need to increase the idle by turning the idle air screw clockwise until the engine does not stall anymore. However, when the idle of the engine remains too high, then you need to lower the idle rpm by turning the idle air screw counter clockwise.
Set the idle needle by holding the car off the ground, open the throttle until the engine reaches the 80% rpm, and then close the throttle. If the engine idles for 2-5 seconds and the idle rpm decreases, then the idle needle is set too rich, so lean this setting by turning the idle needle clockwise. Repeat this process until the engine has a constant rpm for at least 20-30 seconds after the throttle has been closed. If the engine idles for 2-5 seconds and then the idle rpm increases, the engine is running too Iean at the idle needle, so richen the idle needle by turning it counter clockwise to remedy this.
Set the idle rpm by using the idle air screw, and try to find a low but reliable idle rpm. A too high idle rpm makes it more difficult to slow the car during breaking.
Attention: When adjusting the idle needle, this then can effect the idle rpm, use the idle air screw to adjust the low rpm when it becomes too high or too low.
Once you are satisfied with your carburetor settings you are ready to put the car on the track and make the final adjustments.
· Final adjustments while driving.
When ready with the pre adjustments you are now ready to put the car on the track and start your final adjustments. If you have set your idle needle and idle rpm correctly in the pre adjustment phase then you only need to adjust the main needle to find the correct setting and performances of your engine.
Start leaning the main needle by small increments (1/8 of a turn maximum) and run the car again, repeating this sequence until the engine completely cleans out, accelerates well and reaches maximum speed.
To prevent your engine from running too hot, it is advised then to richen the main needle (1/8 of a turn counter-clockwise), since running the engine too lean on the main needle will cause the engine to overheat, resulting in excessive engine wear and possible breakage.
A possible way to check the engine temperature is to apply a few drops of water on the cylinder head. The drops should evaporate only after 3-5 seconds, If they evaporate immediately the engine is too hot, so richen the main needle (1/4 of a turn counter-clockwise) immediately.
Check your engine temperature regularly. Another way of knowing if your engine is running too lean, is when you are driving and the engine starts too loose its power at the low rpm range and no smoke is coming from the exhaust; if this happens, richen the main-needle if you do not want to damage the engine.
Once properly adjusted, the engine should produce a strong, high-pitched sound at maximum speed, and a thin trail of smoke should be visible from the exhaust tailpipe.
NOTE: The carburetor settings may change with changes in weather conditions, fuel, glow plug or exhaust system. After changing any of these, always richen the main needle ¼ to ½ of a turn and then re-adjust the main needle again on the track.
NOTE: When the engine stops, the heat of the engine will go into the carburetor and alter the idle rpm. This can translate into a bad idle rpm, especially when you have your idle rpm a little low. This will come back to normal when you have made at least 1 lap on the track again so the carburetor has reached its normal working temperature.
02-17-2014 | 03:59 PM
#7
The 20* weather here in MN is gonna give you a touh time tuning the engine. Running the Byrons will probably drop your temperature. Ready to run fuels have high oil content which makes them run hotter. Switching to a better fuel will let you lean out the engine, giving it more power, yet run cooler. Might be a good idea to pull the engine out, and make sure its sealed well. Get a new fuel tank and fuel lines and exhaust gaskets. Air leaks are a huge plague in the hobby, and are the easiest to overlook but super simple to fix.
02-18-2014 | 08:49 AM
#10
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Joined: Feb 2014
Posts: 24
Thank you guys all so much for the info! I will have to do some experimenting since we are gonna have a couple nice days here in MN. as for the fuel I purchased one from a hobby shop so it should be new and the other on eBay which god knows how old. That was the Byron's I bought off eBay
03-11-2014 | 08:49 PM
#11
Tech Rookie
Joined: Mar 2014
Posts: 15
Just a heads up. I ran 30% in a stock savage 25 and that engine lasted over 10 gallons of fuel. 100% stock no shims, stock glow plug on 30%. It finally got wore out and a friend wanted to buy the truck so I sold it to him and he put a new motor in it and still has it today. 30% is perfectly safe if you have it tuned correctly. Mine ran like a champ.
03-12-2014 | 04:34 AM
#12
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It's also about 20 degrees here and I can't seem to get this thing to run at the right temp while I lean the hsp. It will over heat every time and won't ever even shift before it gets too hot and I have to kill it. I was running it on dry tar in 20 degree weather and it was getting hot so I'm kinda worried in the summer time it will get really hot! I want it to be fast and run the right temps but can't seem to figure it out and everytime I start from factory setting and try and take it from there but not really any luck
With it being 20 deg outside you would have to run the motor dangerously lean in order to get the motor to warm up.
03-14-2014 | 03:36 PM
#13
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From: Illinois
Never never tune a nitro engine by temp, never. Tune it so you have a visible light smoke trail all the time and the engine responds fast to throttle changes.
With it being 20 deg outside you would have to run the motor dangerously lean in order to get the motor to warm up.
With it being 20 deg outside you would have to run the motor dangerously lean in order to get the motor to warm up.
04-05-2014 | 07:52 PM
#14
Tech Rookie
Joined: Feb 2014
Posts: 10
It's all about the tune when it comes to nitro percentage. One thing I did notice that made a huge difference was the brand of fuel and oil percentage in the fuel. Some engines like to run hot and some run cooler. As long as there is a nice plume of smoke your in the clear. Remember tune to reliability if your only bashing not to squeeze every ounce of power out of the engine unless you are racing. Just my two cents
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