This is my first new 1/8 on road engine. Some engine break in footage here. The break in process was almost done here.
Some notes and observations regarding breaking in an rc nitro engine below, scroll down!
For those who don't know: during the engine break in procedure the engine must be run slower than what it will eventually run when the break in is finished. Until that it will be setup so that it won't go fast even if you went for full throttle. That is why the car here is going quite slowly. But it was going even more slowly in the beginning of the process. It was going at a snail's pace at that time.
It was about to start raining (few drops on during the last two laps) so I thought I have to stop but continued right after ending the recording. These engines don't like rain very much.
This RC car class is so fun that even the motor break in procedure is fun.
Engine: Novarossi .21R-PTA
Car: HB R8
Location: Tattarisuo, Helsinki, Finland.
Before I got this engine an initial breaking in by the seller company had already been done. They used a breaking in bench and had ran a kind of "normal" breaking in bench procedure ( different stages using different RPMs etc..). To describe that procedure would be a very long story.
If the engine is totally new and never run and you are not going to use a breaking bench then you must be very careful with the breaking in procedure. There is plenty of information about that on the internet.
When I took the engine (and the car) on the track first the engine was set so rich (high speed needle) that the car barely started moving, max revs were so low that the clutch barely engaged.
A special break in fuel was used. Two tanks first. Then slightly leaned high speed needle, like one minute or two. Temperature was checked to be something like 80 degrees celsius. Then ran two tanks again. After that the engine was stopped and cooled down.
Then the high speed needle was again leaned a minute and continued the cycle.
No special fuel is necessary. You just must make sure that the engine is rich enough. I used a total of one litre of the special break in fuel. After that a normal 16% fuel was used. There is less oil in it so when changing the fuel to the regular one the high speed needle must be set richer again so that the engine would rev approximately same way than it did with the last tank of the break in fuel.
How to know it is rich enough? Like I said it is rich enough when it has major troubles in moving from the pits. The revs pick up slowly and not very high and it just revs so high that the car barely starts moving. You can then drive it full throttle because it wouldn't get going without the full throttle.
While you are continuing the cycle at some point the engine will start revving high enough that it can engage the second gear. You don't want to break in the engine using the second gear. You want to use the throttle so that the second gear is not engaged. If the gear goes up then you can just reduce throttle slightly so that it will change back to first gear.
If the second gear engages in the very first tanks the high speed needle is not rich enough. There should be something like total of three to five minutes of turning before the engine should be revving enough for the second gear engagement. Of course the three to five minutes of turning must not be done in one setup change but in increments of one minute or so. So that it will require something like five to six tanks before the high speed needle is about to be at a position where the second gear engagement would be possible.
Before starting the engine with the starter box you may want to check the piston is on the lowest point. The engine is very tight and if the piston is near the top dead center point the starting of the engine migh fail. The piston could get stuck on the top point because there has not been enough momentum for it to go past the top dead center. When you position the piston on the lowest point the starter box has better possibilities to get enough momentum for the piston. The position of the piston can easily be checked by rotating the screw on the end of the crankshaft (the screw that keeps the clutch package together). You can notice the are where the piston moves very freely and then just estimate the center point of that area.
Remember always to pre heat the engine before starting the engine with the starter box. You may want to make the heating in more than one small periods so that the heat in the heated engine cooler will transfer to the whole engine. And then heat some more and wait for the heat to transfer again. And repeat one more time. If you heat the engine a too long time with the heat gun the engine cooler temperature will rise possibly too high and the glow plug could be damaged. When you have waited like a minute and the temperature of the engine cooler is still something like 70-80 degrees celsius you are done with the heating.