Running in fresh engine

[T-dog]

Hi guys , have just finished doing a full overhaul on my engine and was just wondering what people do for running in ? . I was going to do 250 miles on millers running in oil with no boost then put normally oil and a new filter in for another 250 with .2 to .4 boost then 1 bar after it’s been run in after 500 + miles . Thanks Toby 

[H_D]

Im running my forged engine in at 7psi on millers for 1000miles oil changes every 250 miles. 1st oil change at 50 miles

[Stu]

Engine run in is a contentious issue and everyone has there own take on it.  If you've had the engine built by an engine builder, then i would suggest talking to them first as they may have their own method that they require you to follow, which will help avoid later arguments if anything should anything go wrong.  If you've done it yourself then you can use any method you like.  I know a couple  of specialist engine builders who drag race at very high level (Robbie at RIPS) who recommend a hard run in right from the outset so I have always followed my own version of that approach (albeit not as hard as they do) and in many years of doing it I've never had any issues - some of my old engines are still going strong 15 years on.   

I start with a couple of heat cycles running 30 mono weight run in oil and straight water coolant - I've heard of the occasional engine having head gasket issues when running glycol.  So start up and run the engine without letting it sit at idle or sit a constant rpm for too long.  It depends on the engine but on a  4e/5e/4age I range from something like 800-4500rpm range as an example.  By having free rev accel and decel it allows both edge of the rings to bed in.  I do this from cold till operating temp then turn it off and let it cool back to ambient before doing it again.  I like to keep the tune lean to avoid bore wash preventing proper ring bed in - I often turn off cold start enrichment in the tune. 

Once the heat cycles are done I head straight to a quick drive with low boost and lots of accel and decel.  Key thing again is to get the tune good as fast as possible and try to avoid running at a constant rpm or idle for too long.  My 4agte had 6psi and 8000rpm within the first 5-10km with good afr's but conservative timing.  After 30km or so I drop the mono weight oil, cut the filter apart and have a good look at whats going on.  If all is ok I run a normal weight mineral oil next with a decent zinc content then run for say 200km before again dropping the oil and checking the filter again.  Third oil change is usually synthetic and my intended normal oil then game on with the tune and the intended boost level.  The tune being on point is key.

There's so many different opinions but I know what works for me and the type of engines I use.  I like the short interval oil changes which give you any tell tales of issues and not being a nana.  But have a chat to a couple of local engine builders and see what they recommend as well.  Getting as many opinions as possible then make a decision based on your own gut feeling is key.

Good luck!