Thread: engine break in.

I just rebuilt my DET and i wanting to know how everyone is going about breaking in their motor and what oil you guys are using to do it??

Good break in oils are high in zinc. You can run diesel oil, or you can run a valvoline VR1 or something similar.

what weight should i use?? ive heard people say i shouldnt use full synthetic until after 5000 miles.

If you've put in new piston rings and honed the bores, you shouldn't use synthetic for the first couple oil changes. You'll want to use organic (regular) motor oil. Synthetic lubricates too well, and won't allow the rings to seat against the bores.

For break-in, I like to keep revs below 2/3 of max and make sure to load the engine quite a bit (lots of WOT in high gears and low revs, and lots of engine braking).

Performed properly, your engine should be fully broken-in in a relatively short period of time. 500 miles is usually enough, or you could do it for 1,000 miles to be extra safe. After that go with full synthetic and don't worry about hitting the red-line anymore.

any idea on viscosity?? should i just use regular 10w30

Mostly, cost is the biggest issue when utilizing synth oil on breakin. Its pointless to spend all that money on oil that is only in the engine for 500-1000 miles. Mostly, you want the filter to remove any particulates left in the engine from the build.

Factory engines are assembled in a dust-free environment and won't require the shorter break-in oil change. Also, many OEMs will use a factory fill synthetic right off the assembly line because of this fact.

The saying "don't use synth on breakin" seems to be a wive's tale to me. As I have broken engines in on synthetic as well as dyno oil and gotten the same results with no ill effects. Even after tearing the engine down and inspecting everything.

Not to mention that most all synthetic oils you buy now are still a hydrocracked dino oil base. Its just more refined and resists viscosity breakdown better, thus lasting longer. But aside from additive pack, its just more refined. Finding a real group IV oil from a PAO base is getting to be harder and harder to find, and you're more likely to see "blends" of these oils and not "full" synthetics.

I'd still use the cheap oil and change it out sooner. Unless you're a baller. Use some good diesel oil if weather is warm. 15w40 works good. If it is cold, like winter time, then use a 10w30 VR1 racing oil for breakin.

Check here for a little bit of decent info.
http://store.forcedperformance.net/merchant2/graphics/subaru_oil/Forced%20Performance%20Recommendations%20for%20Motor%20Oil.pdf

alright will do. thanx for the help.

This is sound advice, this is how my father broke in his motorcycle motor.

I did a diff break in process for my turbo motot.

But i will follow this method for my na sr.

Stratton.

With new rings in i usually give it 400 miles or so. Again with no more than 4500 or so revs but with lots of load in the low end like Ben was saying. Change the oil to synthetic and happy boosting or reving or both. lol. Never had a problem with any break in ive done before.