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Engin breake in

Engine Building Fundamentals

Discussion and questions related to the course Engine Building Fundamentals

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Please give me your opinion on breaking in a turbo engine, lower compression equals lower cylinder pressure. So should you apply a little bit of boost to make up for the lower cylinder pressure to seat the piston rings properly? Thanks JJ

Johan, use it from the get go as you would normally use it.If sh*t is going to go wrong it will happen pretty soon.I would restrict initial boost to the lower settings but drive it normally. I do not believe in mollycoddling the engine when new. If you have the correct rings and bore finish for them, go for it. We would build brand new engines, put them into the cars and go racing after practice and qualifying on Fridays . Saturday full on race action. This is my opinion only, I know a lot of people would argue otherwise.

I definitely advise using a small amount of boost during break in of turbo or supercharged engines. During the early stages I would only advise using perhaps 3-5 psi and this will only require relatively low throttle opening (turbo size dependent of course). As you progress through the break in you can use a little more boost - Perhaps in the vicinity of 5-10 psi.

I'm of the school that if properly built and toleranced engine break-in periods have very little to do with breaking/wearing in parts and far more to do with creating situations and conditions that will allow the user/builder to catch any faults or mistakes in the build.