Engine Break In?

Stang_1973

Founding Member
Jul 13, 2001
565
9
38
San Antonio, Tx.
So now that i have my car back, i took it to school. The guys wanted me to show off a little but I explained i couldn't cuz i have to break in the engine.
The mechanic said don't go over 60 MPH for 500 miles. Some "tuner" at school said I shouldn't go over 50 for 1000 miles. Is this guy right or am I just crazy for paying attention to him.

Any other do's and dont's I should know about while I break the engine in?
 
Well i'm no expert, but this site seems pretty acurate to me. Everything i've ever heard about breaking in engines all go along the same lines:

1. Don't push the thing too hard, which is why people say no faster the 60 mph, or 3500 rpm or whatever. The number is just sort of a standard so that you don't burn the thing too hard.

2. Vary the speed so that the engine doesnt' just do the same thing all the time. Varying pressures and things are better then just one, cause then things move around a little better or whatever.

3. Usually by the time you've drivin 500 miles varying the speed, but not pushing too hard (although once in a while a little rough) Things have pretty much done all the settling and seating their gonna do.

My opinion is that there is no "magic number" or anything, realisticly as long as you follow the basic idea it'll be ok.

Another word of advice for those rebuilding engines:
If your having someone else do the job for you, don't find the cheapest one you can, that's what my dad did, and now the car is seriously screwed. It presents me with the most mysterious problems.... (it is my daily driver) make sure you don't have some yahoo doing the job, because it'll end up costing you more down the road. Bite the bullet and make sure it gets done right. Sorry, i'm just a little bitter about this right now, because i have to get a new car. :nonono:

anyway, good luck with the engine.

Oh yeah, be sure to change oil, filter all that good stuff after the break-in....
 
Just drive it like you plan to everyday after its broken in. If your doggin it to hard now and something breaks then it was going to break anyway. Just change the oil at about 500 miles or so after the first startup to get all the extra metal shavings out then go on the normal oil change routine.
 
I agree with the posted information, but even its a little conservative for my taste. I build my engines, get the tune right, and run them hard. I change the oil at 500 & 1000 miles to ensure any leftover junk from the machine shop is removed and check for metal particles. I've done about 30 SBFs and haven't had any problems.

New cars? Just get off the lot and drive it like you stole it!
 
My break in was for 500 miles under 2500 RPM and below 55. Pretty much residentail area driving. Now, but boss just did the 20 min cam break in, then ran the @#*% out of his motor, and he has yet to have a single problem with it. So this whole break in thing may or may not be true. In my mind, it's not worth the risk.

-Shaun
 
I have understood to breaking in an engine you should vary the load on the engine, like driving up hills or drive at a constant speed the pass a car then slow down slower than you were going before. Its also a good idea to put a magnet on you oil filter and after you change it, cut it open and look to see what it had inside.Dont forget you also need to breaking the cam before you do any driving, unless you have a roller cam.
 
Its alot easier to put a filter screen on top of the oil filter... it will catch any debris, so you don't need to cut the filter apart and search around for particules. There's also a bypass hole to prevent clogging. They're cheap and available at many parts stores.
 
On my last engine ( aluminum headed 302 in my 93GT ) I ran it long enough to get the carb dialed in (prolly 15 miles) before I was powershifting it at 7000 rpm. It had a roller cam in it, so I didn't have to break in the cam, but on my other non-roller cam engine I only ran it 20 mins at 2000 rpm to break the cam in..shut it off and rechecked/adjusted the rockers and was hitting the rev limiter as soon as the tires hit the pavement....The engine in my 93GT is still running strong after 30,000 miles.