razzor
05-13-2008, 03:07 AM
There are a few ways of running in nitro engines ,i am going to post the two that works for me and makes the most sense.
1:
The engine is very easily influenced from its first drop of fuel and run in so make sure you do it right and once only.
Check for all the usual air leaks in line tank and pipe.
Seal carb
Start engine and run in (procedure avail)
once the engine is settled in take time to tune it right and once only. What people don’t realise is that once an engine is dialled it only needs very minute adjustments from track to track or maybe none at all.
Ok start with the idle, tune idle so it stays running just before clutch engagement.
Run car on selected surface with selected tyres.
Fill tank and run car till half tank then tune HSN till you get max response
for race tune lean HSN till it bogs under load then richen till the bog ceases. This will give you best tank time and best performance. (This may take more than half a tank to do so take the time to do it properly)
By this stage you may notice the idle creep up, change to suit
then tune LSN. Same again tune while engine is hot, pinch fuel tube at carb it should take a few seconds to rev up and die safe area is 3 to 6 seconds more than this may cause too much load up and bog on take off.
For race tune usually pinch test would cut engine off almost immediately,
Now take the time to assimilate racing or running conditions and see how it behaves, if all is good then you’re almost there. If needed then do some fine tuning. Time your tank if you’re getting about 8 mins then id say your in the ball park, many things can change this figure but it’s a general idea.
Ok now this will get you in the ball park, if your engine is running too hot and bogs then what do you do ? Richen.
Remember running an engine nice and hot from day 1 will allow it to last to its life expectancy. Running an engine cool i.e. 100 deg c will shorten its life by about 50%
Hope this helps!
Source MM
================================
2:
Josh Cyrul wide open throttle method.
Engine Break-In 101
In the area of engine break-in, there are several different procedures that have been used over the years. Different manufactures, top drivers, and hobby store experts all vary in their opinion as to which is best. Over the past 10+ years of nitro racing I have found this procedure to give me good results in both areas of on-track performance as well as reliability.
Install the new engine into your chassis complete with clutch and ready to go as if you were going to race. Take a screwdriver, glow igniter, starter box, and a full bottle of fuel to a remote area where you won't annoy anyone with a running engine. Start your engine and allow it to warm up with several short ½ throttle “blips”. Once your engine has some temperature in it you can begin the break-in process. Start by opening the top end needle 1 full turn. Open the carburetor to full throttle and hold it there. Open the top end needle until the engine flames out. From here, close the top end needle ¼ turn and restart the engine again running it at full throttle. Run the engine full throttle for 3 tanks and shut the engine down.
Allow the engine to cool for 15-30 minutes. Once the engine has cooled down, run through the same process again for two additional tanks. On the third tank close the top end needle by ¼ of a turn. Instead of holding the engine at full throttle, start using the throttle by doing 2-3 second bursts of full throttle. Once you have done this for ½ of the tank close the top end needle another ¼ of a turn and continue throttling the engine. Continue closing the top end needle ¼ turn per every ½ tank of fuel. Do this until you have run a grand total of 8 tanks through your engine and then shut the engine down.
Allow the engine to cool for 15-30 minutes and then you are ready to hit the race track. Drive two tanks rich around the track slowly closing the top end needle sneaking up on that perfect mixture. At the end of the second tank your engine should be tuned to race speed. This will give you a total of 10 tanks of fuel through your engine before you really start to lean the mixture for ultimate power.
The reasoning behind this break-in procedure is that there is always a large volume of fuel flowing through the engine. Large volume of fuel means plenty of oil and lubrication for the break in process. This also helps flush out any burrs or small pieces of material that may have been left over from the manufacturing of the engine. Also, the engine has a load placed on it by trying to cycle all of the fuel through it – somewhat similar to the load that you will put on it out on the track when you try to power your car around the track. Last, the engine is broke in with rpm – if you break the engine in at idle then you will not be seating the piston, sleeve, and connecting rod at anywhere near the rpm that it will have to be ready for out on the race track.
This is the procedure that I have used with good success over the years of nitro racing. When I've hurried the break-in process I have had some engines last 30 minutes to 4 hours of racing. When I've taken my time and run through this process I've run engines as long as 16 hours of racing!! Yep, same piston and sleeve!!!! Be patient and have fun!!
Good Luck!!
Josh Cyrul
CEFX
1:
The engine is very easily influenced from its first drop of fuel and run in so make sure you do it right and once only.
Check for all the usual air leaks in line tank and pipe.
Seal carb
Start engine and run in (procedure avail)
once the engine is settled in take time to tune it right and once only. What people don’t realise is that once an engine is dialled it only needs very minute adjustments from track to track or maybe none at all.
Ok start with the idle, tune idle so it stays running just before clutch engagement.
Run car on selected surface with selected tyres.
Fill tank and run car till half tank then tune HSN till you get max response
for race tune lean HSN till it bogs under load then richen till the bog ceases. This will give you best tank time and best performance. (This may take more than half a tank to do so take the time to do it properly)
By this stage you may notice the idle creep up, change to suit
then tune LSN. Same again tune while engine is hot, pinch fuel tube at carb it should take a few seconds to rev up and die safe area is 3 to 6 seconds more than this may cause too much load up and bog on take off.
For race tune usually pinch test would cut engine off almost immediately,
Now take the time to assimilate racing or running conditions and see how it behaves, if all is good then you’re almost there. If needed then do some fine tuning. Time your tank if you’re getting about 8 mins then id say your in the ball park, many things can change this figure but it’s a general idea.
Ok now this will get you in the ball park, if your engine is running too hot and bogs then what do you do ? Richen.
Remember running an engine nice and hot from day 1 will allow it to last to its life expectancy. Running an engine cool i.e. 100 deg c will shorten its life by about 50%
Hope this helps!
Source MM
================================
2:
Josh Cyrul wide open throttle method.
Engine Break-In 101
In the area of engine break-in, there are several different procedures that have been used over the years. Different manufactures, top drivers, and hobby store experts all vary in their opinion as to which is best. Over the past 10+ years of nitro racing I have found this procedure to give me good results in both areas of on-track performance as well as reliability.
Install the new engine into your chassis complete with clutch and ready to go as if you were going to race. Take a screwdriver, glow igniter, starter box, and a full bottle of fuel to a remote area where you won't annoy anyone with a running engine. Start your engine and allow it to warm up with several short ½ throttle “blips”. Once your engine has some temperature in it you can begin the break-in process. Start by opening the top end needle 1 full turn. Open the carburetor to full throttle and hold it there. Open the top end needle until the engine flames out. From here, close the top end needle ¼ turn and restart the engine again running it at full throttle. Run the engine full throttle for 3 tanks and shut the engine down.
Allow the engine to cool for 15-30 minutes. Once the engine has cooled down, run through the same process again for two additional tanks. On the third tank close the top end needle by ¼ of a turn. Instead of holding the engine at full throttle, start using the throttle by doing 2-3 second bursts of full throttle. Once you have done this for ½ of the tank close the top end needle another ¼ of a turn and continue throttling the engine. Continue closing the top end needle ¼ turn per every ½ tank of fuel. Do this until you have run a grand total of 8 tanks through your engine and then shut the engine down.
Allow the engine to cool for 15-30 minutes and then you are ready to hit the race track. Drive two tanks rich around the track slowly closing the top end needle sneaking up on that perfect mixture. At the end of the second tank your engine should be tuned to race speed. This will give you a total of 10 tanks of fuel through your engine before you really start to lean the mixture for ultimate power.
The reasoning behind this break-in procedure is that there is always a large volume of fuel flowing through the engine. Large volume of fuel means plenty of oil and lubrication for the break in process. This also helps flush out any burrs or small pieces of material that may have been left over from the manufacturing of the engine. Also, the engine has a load placed on it by trying to cycle all of the fuel through it – somewhat similar to the load that you will put on it out on the track when you try to power your car around the track. Last, the engine is broke in with rpm – if you break the engine in at idle then you will not be seating the piston, sleeve, and connecting rod at anywhere near the rpm that it will have to be ready for out on the race track.
This is the procedure that I have used with good success over the years of nitro racing. When I've hurried the break-in process I have had some engines last 30 minutes to 4 hours of racing. When I've taken my time and run through this process I've run engines as long as 16 hours of racing!! Yep, same piston and sleeve!!!! Be patient and have fun!!
Good Luck!!
Josh Cyrul
CEFX