Originally Posted by
DS Motorsport
Add 10% of the castor oil to the first liter of fuel you are going to use for break in.
Adding a straight 10% of castor oil to a regular fuel is a lot of oil that will not be burnt and leave a lot of oil deposits on the engine.
Originally Posted by
DS Motorsport
Open up the high speed needle about 1.5-2 turns from factory settings for the first 4-5 tanks on the starterbox.
These 4-5 tanks will be at WOT, the wheels shouldn't start turning at this stage, but close to the point they will start turning.
This is a very bad advice, with such rich adjustment of the carb, engine will not reach never their operating temp and the work done with the hairdryer will be futile.
WOT + Fourstroking create a lot of stress on the conrod and crank and is a sure recipe for a short living engine due to excessive wear on the upper side of the sleeve and the crown of the piston, just where the most pinch is.
Is better to go with a rich setting that allows the car to move but not shift (if is equipped with a 2speed trans) or do it very late, not allow to wind it and have the engine at about 90-100ºC.
Is very important to not run dry the fuel tank just because this creates a lean condition that you may not want breaking-in. Better to stop it and leave some fuel on the tank and allow to cool it to ambient temp.
Is very important to reach 90-100ºC just because the sleeve pinch will be gone but piston and sleeve will be almost at their normal size and wear will be almost zero, just enough to mate them two.
After 5 or 6 tanks like this allowing the engine to self cool with the piston on the BDC to not being trapped by the sleeve, start to drive and in rounds of 3 or 4 laps, start to lean very slowly (in half hour increments).
Driving and acceleration should be nimble and gentle, not allowing the engine to run full wind for long periods of time.
Temp will start to creep and raise a little, is quite normal due to the leaning but the cooling will be higher due to the more speed that car will reach.
Better to not rush a break-in, the key points are:
- Heat is not your enemy, is your friend. Like friends, just control it and put enough to reach normal temperatures. 70ºC is too cool and wear is really high. 90º or 100ºC is a much desirable temp range with much lesser wear and effort for the conrod and crankpin.
- Do not allow the tank to run dry. This may cause an overly lean condition that you do not want.
- Between tanks, allow it to cool putting the piston on the BDC to prevent being trapped on the sleeve.
- Not rush it... is better to spend a little more time than runing a P/S/C set and need to start it over.
- Use a good fuel and you do not need to add it more straight oil to the existing mix. Use whatever you want or what you have at hand, but remember: Use a good fuel.