Running In Oil

[Duncan]

I look for the longest hills I can and run up them at high gears at medium revs with medium throttle (make sure it's not too much load, pinging would be "a bad thing"). And when I say no boost, I mean as little as possible - turn off the boost controller and just run wastegate boost. A run to somewhere like bathurst up bell's line is perfect.

Also, you should avoid engine braking on the way back down, it's not good for a motor running in.

Alternatively, it is dead easy on a dyno because it creates the load you want - its much quicker that way but not everyone has one handy

[Piggaz]

Also, you should avoid engine braking on the way back down, it's not good for a motor running in.

What's the reason behind this?

[Duncan]

sorry nfi, but I have been told this by more than 1 good tuner. I assumed that acceleration and deceleration have difference forces on the bearings that matter during the first few klm.

BTW, I should add, running in a motor is about getting the bearings seated correctly in the first very short time, and then about the piston rings bedding into the bores for the remainder. If you do a compression test before and after run in you will find a very large difference eg 130psi vs 180psi.

The only other important thing is to change the oil nice and early so anything that was missed in the clean, and any ring and bearing run in material is gone. Here is an oil analysis I had done on run in oil:

[discopotato03]

Long short a mineral oil with the lest friction modifiers additive package . Cheaper Castrol in whitish grey bottle is fine .

If really keen change it and filter after the first test drive .

As above go find the longest mountain to climb and drive up it at low/medium revs and WOT .WOT gives the best cylinder filling and highest cylinder pressure to get behind the rings and push them out against the cylinder walls . Its the extra pressure the rings exert on the bores that allows the cross hatching to wear a working surface on the faces of the rings and bores .

Turbo engines are easier if anything to run in because you have a physical pump to raise cylinder pressures and get the rings pushing out onto the roughened up (honed) bores .

It really doesn't take very long to get a working surface on the crankshaft bearings if the block and crank journals are to spec .

At 400 I call my engines run in enough for a dose of good mineral oil and after 2000 more its over to what ever I intend to run the thing on .

Never ever had a problem with a freshened engine that was honed or bored and honed properly meaning round parallel cylinders and always used chrome rings .

A .

[lilcrash]

Also, you should avoid engine braking on the way back down, it's not good for a motor running in.

I was always told to use engine braking.

[KiwiRS4T]

I was always told to use engine braking.

Me too - by an engine builder not a tuner. He told me running in should be pretty much done in half an hour.

[lilcrash]

Every single person ever has told me that. This is the first time I've heard differently.