how to break in a new built engine / rebuilt engine

[franx]

Hard or gentle ? I had instructions not to take it over 5000 rpm for the first 1000+ km's , and i stuck to it (as hard as that is..) . I did however let the engine really work hard up to these 5000rpm , on every level. Very fluctuating rpm's, pushing it hard through different rev ranges. Important to get the new piston rings fully worn in by not taking it too gently. All of course when fully warmed up, oil up to temp i mean !

Now i' ve just changed the first oil after 1500 km's and am revving it a bit harder past the 5k . The new engine is a ph1 lump with a 182 exhaustmanifold, decat , Schrick cams, matched inlets and modified air-intake (V6 box straight onto the TB, worked well on my other setup!)

Was wondering if anyone of you had to go through this episode of "running in" an engine and wanting to know your thoughts on this .

 

[The Fatty]

I seem to remember people saying that the ones that were pushed hard from the beginning seemed to give better power outputs later in life. not sure if thats true though :/

 

[franx]

my former engine (RIP) was exactly like you stated ; pushed hard from new and made 195 with cams on honest rollers. It went like a train, very loose engine i guess. Was on 120,000 km before it had a mishap. I'm wishing to give her the same treatment (except for the mishap that is ..)