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Title:How to break in an engine

Author:yt500pmd

There are 3 ways you can break in an engine:

1. On a dyno
2. On the street, or off road
3. On the racetrack

Warm the engine up completely!!

Then, using 4th gear or D in an automatic:

• Do Three 1/2 Throttle dyno runs from 40% - 60% of your engine's max rpm.
  Let it Cool Down For About 15 Minutes
• Do Three 3/4 Throttle dyno runs from 40% - 80% of your engine's max rpm.
  Let it Cool Down For About 15 Minutes
• Do Three Full Throttle dyno runs from 30% - 100% of your engine's max rpm.
  Let it Cool Down For About 15 Minutes Go For It!!
• NOTE: If you use a dyno with a brake, it's critical during break - in that you allow the engine to decelerate fully on it's own. (Don't use the dyno brake.) The engine vacuum created during closed throttle deceleration sucks the excess oil and metal off the cylinder walls.

You'll notice that at first the engine "smokes" on deceleration, this is normal, as the rings haven't sealed yet. When you're doing it right, you'll notice that the smoke goes away after about 7-8 runs.

On the Street:

Warm the engine up completely:

• Because of the wind resistance, you don't need to use higher gears like you would on a dyno machine. The main thing is to load the engine by opening the throttle hard in 2nd, 3rd and 4th gear.
• Realistically, you won't be able to do full throttle runs even in 2nd gear on most vehicles without exceeding 50 mph / 80 kph. The best method is to alternate between short bursts of hard acceleration and deceleration. You don't have to go over 65 mph / 104 kph to properly load the rings. Also, make sure that you're not being followed by another vehicle when you decelerate, most drivers won't expect that you'll suddenly slow down, and we don't want anyone to get hit from behind!!
• The biggest problem with breaking your engine in on the street (besides police) is if you drive the vehicle on the freeway (too little throttle = not enough pressure on the rings) or if you get stuck in slow city traffic. For the first 200 miles or so, get out into the country where you can vary the speed more and run it through the gears!
• Be Safe On The Street! Watch your speed! When you're not used to the handling of a new vehicle, you should accelerate only on the straight-aways, then slow down extra early for the turns. Remember that both hard acceleration and hard engine braking (deceleration) are equally important during the break in process.

Warm the engine up completely:

• Do one easy lap to warm up your tires. Pit, turn off the vehicle& check for leaks or any safety problems. Take a normal 15-minute practice session and check the water temperature occasionally. The racetrack is the perfect environment to break in an engine!! The combination of acceleration and deceleration is just the ticket for sealing the rings.
• Go For It!!

The piston on the right was broken in as per MotoMan's instructions.

After a full season of hard racing:

• Perfect Ring Seal ...
• No Scuffing ...

Change Your Oil Right Away !!

The best thing you can do for your engine is to change your oil and filter after the first 20 miles. Most of the wearing in process happens immediately, creating a lot of metal in the oil. Plus, the amount of leftover machining chips and other crud left behind in the manufacturing process is simply amazing !! You want to flush that stuff out before it gets recycled and embedded in the bearings, oil pump etc...

This information Compiled by motoman@mototuneusa.com
from his website
http://www.mototuneusa.com/break_in_secrets.htm

Edited by yt500pmd\JPadilla
Submitted by yt500pmd\JPadilla