Originally Posted by
JBSpeed
Folks,
I've been reading up on breaking in my fresh un-factory broken Mito35 (ps, thanks santa!) and can see from the forum 2 clear schools of thought, although some time has passed since updates on the Sir Ron Paris bible. So a question to all the Nova guys, what's the preferred method for the engine considering build quality and materials of the Novas (my first one, been Picco/Reds guy, but felt like trying something new for 2017):
1: "Old School - Run rich on box for multiple tanks" - This method keeps plenty of fuel and oil in the engine during break in to flush engine of the little bits that may have been left after build, but the engineer in me considers this not as sweet a break in as the "new school" heat cycle approach as described in the "break in bible" in this forum. I figure an engine with the quality of a novarossi won't have material left in to worry about (checked, cleaned and flushed).
2: "New School - Heat cycle on track" - Appeals to me, takes time, but will end up with a finely honed engine. Your experiences concur?
Any experiences comparing the two on a novarossi?
Final question, running in is in Singapore, it's 35degC (95degF) ambient. Still worth applying heat gun/wife's hairdryer before starting the lump (engine is worth risk of aforementioned wife wrath of stealing hair dryer).
Thanks folks, and all the best for 2017!
The most important thing is to make sure the engine is hot during break in. I've seen many people running in engines that are too rich and cold - this isn't achieving break in at all! I use a 1/10 buggy rear tyre insert to keep the heat in the engine while breaking in.
Just one tank on the box at a slightly higher than normal idle ensuring the engine is reaching at least 75-80 degrees celsius. Then slowly start running the engine in the car. Over the next 8-10 tanks leaning the top needle about 1/8 turn each tank (stop when engine approaches race tune and back it off 1/8 and stay at this setting for the rest of break in). Initially avoid full throttle for the first few tanks and then progressively use more throttle for longer periods. For the final couple of tanks use full throttle for progressively longer periods to full seat the piston in the sleeve at TDC.
Stop and let the engine cool every 2nd tank to heat cycle. You need the engine fairly hot during this process and not excessively rich. Keep the engine at least 80 degrees celsius and towards the end of the process around 100 degrees. Remove the head cover once the engine can sustain at least 80 degrees celsius on its own while running in the airflow.
Final race tune can be achieved at around 12 - 15 tanks depending upon the engine (it'll stop going rich by itself) or around 1.5 hours total time. Remember it is a Novarossi which is generally superior in quality and it does take a long time to properly break in a Novarossi. You may find the engine doesn't actually "drop it's nuts" until the 2 gallon point!
YES! Use the wife's hair dryer to heat the engine before each start.