Well it all depends ! I can tolerance an engine so it needs almost zero breakin, just seat the bearings and the engine is ready to race and will perform at peak power almost immediately.....However you will see slightly less lifespan on the piston/sleeve fit before it needs a pinch.... However because there was no real pinch to begin with the engines internals will stay in near perfect condition...no stress on the rod, no stress on the bearings and no wasting 2 gallons of fuel waiting for the engine to hit prime.....So just a repinch and the engine is like new again....Many people are willing to sacrifice a tiny bit of lifespan to avoid all the hassles of breakin.... And with the modern pinching tooling its really not a big deal to snug up the fitment when its time....

Now I don't lap all the engines this way, some engines come from factory with way too much pinch, and will take nearly 2 galllons to fully loosen up, and by that time the connecting rod and bearings have taken a beating, not to mention the hassles involved with trying to work with a overly tight engine...With engines like this I lap the fitment so its more user friendly, it still needs to be broken in, but we are only talking 1/2 gallon at most till the engine is at prime....This saves the user plenty of fuel and time, and still retains the original lifespan of the piston/sleeve set....

So in other words I can lap the piston/sleeve fitment to my customers request.. a looser fit will be track ready almost immediately and make full power right out of the gate, but we will lose some overall lifespan on the piston/sleeve fitment...Or I can lap the engine so its still retains some pinch, but the breakin will be greatly reduced from its original state....

So far I have sold several hundred hand lapped engines and all my customers love the way it works.... And currently we are offering this service free with all of our modified engines !