View Full Version : To break in an engine: run it HARD!

01-25-2005, 10:42 PM


01-25-2005, 11:00 PM
Yup. Thats how I've always done it.

01-25-2005, 11:18 PM
Yup. Thats how I've always done it.
I'm still a bit skeptical about this method, although some of it does make sense to me. How credible is this guy? What if its just a big joke... That would suck.

01-26-2005, 01:32 AM
I've used this method on the two engines that I've broken in, and have had no problems what so ever. I've always been told to break it in how you intend to drive it.

01-26-2005, 03:08 AM
It might be good for the engine, but remember the clutch has to be broken in also.

01-26-2005, 03:19 AM
That's how I will break my engine in as well when it goes in this weekend.

01-26-2005, 10:19 PM
I have always run engines in as cold as possible. On any of my projects I will always try to time engine completion to end in winter. Another tip is to use thin cheap engine oil. I have used these techniques on hundreds of engines over the years and never had any problem.

www.littleoldladys.com (http://www.littleoldladys.com)

01-27-2005, 09:27 PM
Run it hard for about 200 miles... drain the oil... another 300 miles... drain again. Resume normal driving.

On my focus' second engine... I went straight to the synth oil and ran the living crap out of it in the first 1000 miles (track day even) and haven't had ONE problem with it in its 50000 miles.

01-28-2005, 08:02 PM
peopel have been breaking in engine the smooth way forever and the run past the 300 000 KM marks easily, even 400 000 on toyotas. Does that methods shows similar results? I say if it ain't broke don't fix it :P.

01-29-2005, 12:36 AM
i think thats how you break your engine ... not break it in.

if you read a new cars owners manual, it tells you not to beat on the car for the 1st 1,000 miles or so because its a fresh engine that was just built. you should do the same with any rebuild engine.

06-15-2005, 09:16 AM
This thread just made me think of drag racing motors.. they rebuild them.. then go pound them. I see no break in period in there...

06-15-2005, 12:05 PM
Drag engines are run like that because you expect to have to rebuild them.

This debate has been going on as long as engines have been being built. It is even more popular than Sythetic over Conventional. Auto over Manual...

You break you engine in however you want.

For me, I will keep the revs down and change my oil every 500 miles for the first 2k. At the final oil change I start using synthetic. I break it in on conventional. I have done this since the first engine I built to the most current.

BTW that first engine was a SBC, it has over 200k on it now and still passes a leak down flawless. That is proof enough for me as to what works.

06-15-2005, 05:55 PM
I followed that guide after my Supras 7MGTE rebuild. I did 5 oil changes the first 3k.

I went WOT the first 10min, followed the guide with Iron rings.

180psi on all 6 cyl, so I'm sold!

06-16-2005, 02:17 AM
Wow sounds great to me, he tells all aspects of the story, sounds credible..

06-16-2005, 03:15 AM
i did this on my first rebuild.... although slightly modified.

I basically ran it to around 50% of max revs, but at WOT in all gears.
In the GT4, 4000tpm in 5th gear is around 140km/h. Not to mention pulling like a mofo up a hill... If that isn't load than i don't know what is.

The important thing, and its the same across both methods of running in. Is load the engine up. Find a hill and drive up it. But don't let it lug.