NewbeDoo

Hi I'm new here, this is my first post and I am picking up my first Scoob on 1st March (MY03 WRX) and have heard many conflicting things about running in. There seems to be two diametricaly opposed schools of thought

a) Take it steady for the first 1000miles (<4000RPM) then gradualy increase the revs.

b) follow the advice summarised on this page http://mototuneusa.com/break_in_secrets.htm

I am sure this has been discussed at length in the past, but I could not find any posts where new cars had been wrecked by using method B.
Cheers
Tom

Josh L

I'm no expert, but what I have been told by informed sources is that running a new engine hard might increase the power marginally, but reduce it's life.

What I do know is that Subaru put a thinner running in oil into the engines, which is changed at 1000 miles, and several very knowledgable members of the BBS ALWAYS run in their cars properly, even detailing the routes taken to do this in the minimum amount of time.

The advice on that link may be correct, or it may not. However it's your engine that's going to suffer if they're wrong.

Josh

speedking

What has engine rpm got to do with pressure? I would have thought that the volume of air drawn in and compressed per cycle was very similar at 6000rpm or 2000rpm, therefore the compression ratio and combustion pressure are similar. The pressure on the rings will be similar. Also why the need to blast through several gears? 6000rpm in 1st will give the same sealing pressure as 6000rpm in third, the engine doesn't know that a higher gear has been selected downstream?

Sits back and waits for the more knowledgeable to put me right.

Don't forget that it isn't just the engine that needs running in, the gearbox, water pump, brake pads, clutch, wheel bearings, etc, etc. all have rough edges that are better smoothed off gently than torn off violently.

Why don't you try the blasting method of running in (sprinting in ) and report back later? Personally I would stick to Plan A.

j_p_h

Havent had to run a scoob engine in yet, but did my old cossie after its re-build. Same as running a scoob in basically. Use thin running oil in then after 500 miles the cossie and a 1000 on the scoob got the proper oil then another 500 at less than 3 RPM on the cossie 4 on the scoob. then just gradually begin to rev the engine more say another 500 miles then nail the hell out of it lol.

j_p_h

Also do plenty types of different driving. Try and do a lot of A and B road driving and never stay at the same constant speed. Heard a lot of people say do motorway driving as the miles go on quicker i would say this is a big no no.

HardcoreSax

Should only take around 500 miles to bed the piston rings in, if it isn't done properly the rings may glaze, meaning they won't achieve a good seal.

Once its up to normal running temps you should give the engine short sharp blasts of full throttle, the high pressure created will draw the rings out against the bore helping them to bed in. Then snap the throttle closed, this creates a vacuum in the cylinder which will draw up extra oil to cool the rings and the cylinder walls.

For the first 500 miles the engine can be run to 80% of its max revs, but avoid sustained periods of high revs and try and to vary the revs as much as possible rather than cruising at constant speed.