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View Full Version : Miles to drive for break-in



2wrench
11-18-2008, 10:44 PM
So I changed out the oil once after only about 150 miles.

So I'm thinking to drive at under 3000 rpm's for the next
500 miles.

Then it's time to retorque the head and verify the
valve clearances, right?

How soon can I open up to harder driving?

foxtrapper
11-19-2008, 08:11 AM
No one absolute correct answer to your question. Personally, I'm more inline with the folk that think getting the rings seated is pretty important, and for that you do use some throttle romping.

tr8todd
11-19-2008, 08:19 AM
The most important thing is to get a new cam broken in properly. Once the motor starts for the first time, you need to get the engine up to temp and run it at 2K RPM for 20 minutes or so. Right after that, you need to change the oil to remove all of the break in lube that the engine builder used. Use only petrolium based oil for the first couple of oil changes before going to synthetics. After an hour of run time or so, I consider them broken in.

crj7driver
11-19-2008, 12:27 PM
I used this on my motorcyle, check out the link https://www.rc51.org/breakin.htm for some detailed instructions/viewpoints.

The guy that wrote this is a bit of a guru so I trust his viewpoint.

Good Luck

RonMacPherson
11-19-2008, 12:43 PM
Okay, you're already past the cam break-in period. You've changed the oil, so essentially flushed any fongooohla out of the system.

All that's left is bedding in the rings. For that you want varying throttle and load. In essence do not keep the engine at a steady rpm level(other than slight trailing throttle) for any period of time. Give it a little gas, or ease up on the throttle. rpm limitation is not the most critical thing.

Whatever you do, let the engine idle for 15-20 seconds after each run before shutting off.

500 miles from build to last non-detergent oil change and you're good to go.