A very controversial topic !! Engine Break In Procedure
Posted: Tue Oct 09, 2018 9:57 am
I'm starting this thread in response to a discussion on the one WhatsApp group that many of the members are on.
With Manny buying a bakkie, mention was made that he's still "running it in" after half a tank of fuel. This is my view on the age old question of how to "run in" a new motor, be that a new vehicle or a rebuild motor.
Have a look at this link and give your views. http://www.mototuneusa.com/break_in_secrets.htm
With my years competing in different types of motor-sport, I've learned may lessons on how to abuse and brake motors. I feel that the break in procedure that I have followed works well in both new motors and rebuild or refreshed motors. Running in or breaking in a motor has nothing to do with the crank bearings but how the rings will seat in the cylinder bore and how well they will seal. The bearings clearances are either correct or not and nothing can be done to correct those after assembly. Using the correct oil is also critical in this phase of the engine's life.
The procedure I use is modified from the recommended Cosworth procedure as I don't have access to an engine dyno to do it before fitting the motor to a vehicle. The RPM that I quote here are what I have used with the Toyota 4AGE 1600cc petrol engine. For other motors work on a percentage of the RPM to the red line for that motor. (20%, 40%, 60% and 80% of red line RPM)
After a rebuild and installation of the motor I will leave the sparkplugs out and spin the motor over until I have positive oil pressure. Then I'll start the motor and hold the RPM steady at 2000RPM for about 5 minutes. This run is more to carry out a leak check on all the external systems than anything else. After shutdown and the checks the motor must be left to get back to ambient temp before continuing. All of the next runs I did at night on the highway when traffic wasn't a problem. The next run I limit the RPM to 4000RPM. After an easy drive to the highway to get temps up I do a 30 drive where you use maximum throttle opening till the RPM limit and then run against compression for as much of the drive as possible. This is repeated for all the runs at the different RPM levels. After the 80% RPM run do an oil and filter chance and fill with the best synthetic oil specified for that motor.
On a road car this full procedure isn't possible but the principal can be applied with very good results. The important bit is to get the pressures in the cylinder high to force the rings out against the cylinder bore during acceleration and then relieve the pressure to allow the oil and fuel to carry away the cylinder material that has been worn off. With all my road vehicles that I've had from new I've had minimal oil usage between services and I believe it's as a result of the process I've followed.
With Manny buying a bakkie, mention was made that he's still "running it in" after half a tank of fuel. This is my view on the age old question of how to "run in" a new motor, be that a new vehicle or a rebuild motor.
Have a look at this link and give your views. http://www.mototuneusa.com/break_in_secrets.htm
With my years competing in different types of motor-sport, I've learned may lessons on how to abuse and brake motors. I feel that the break in procedure that I have followed works well in both new motors and rebuild or refreshed motors. Running in or breaking in a motor has nothing to do with the crank bearings but how the rings will seat in the cylinder bore and how well they will seal. The bearings clearances are either correct or not and nothing can be done to correct those after assembly. Using the correct oil is also critical in this phase of the engine's life.
The procedure I use is modified from the recommended Cosworth procedure as I don't have access to an engine dyno to do it before fitting the motor to a vehicle. The RPM that I quote here are what I have used with the Toyota 4AGE 1600cc petrol engine. For other motors work on a percentage of the RPM to the red line for that motor. (20%, 40%, 60% and 80% of red line RPM)
After a rebuild and installation of the motor I will leave the sparkplugs out and spin the motor over until I have positive oil pressure. Then I'll start the motor and hold the RPM steady at 2000RPM for about 5 minutes. This run is more to carry out a leak check on all the external systems than anything else. After shutdown and the checks the motor must be left to get back to ambient temp before continuing. All of the next runs I did at night on the highway when traffic wasn't a problem. The next run I limit the RPM to 4000RPM. After an easy drive to the highway to get temps up I do a 30 drive where you use maximum throttle opening till the RPM limit and then run against compression for as much of the drive as possible. This is repeated for all the runs at the different RPM levels. After the 80% RPM run do an oil and filter chance and fill with the best synthetic oil specified for that motor.
On a road car this full procedure isn't possible but the principal can be applied with very good results. The important bit is to get the pressures in the cylinder high to force the rings out against the cylinder bore during acceleration and then relieve the pressure to allow the oil and fuel to carry away the cylinder material that has been worn off. With all my road vehicles that I've had from new I've had minimal oil usage between services and I believe it's as a result of the process I've followed.
