What do you guys think of this tech article about engine break in?

CaifanSC

SCCoA Member
Somebody was kind enough show me this article. I read through it and it appears to be indeed very controversial. In my relatively short amount of time working on cars I've always heard that you have to take it easy on the engine once rebuilt for 500-1000 miles depending on your preference. In any case, check out the article.

http://www.mototuneusa.com/break_in_secrets.htm
 
That is a GREAT article! Not many are bold enough to actually come out and say it.

The #1 point that I think that he made was NO SYNTHETIC OIL!!! Can't stress that enough!

We break in all of our race motors at around 4,500RPM from the time that they fire. They stay that way for about a minute with slight variations in rpm of about 1,000 rpm. Shut them down, let them hot soak and drain for 30 minutes. Change the oil and cut the filter open to see what kind of metal we are getting or hopefully NOT getting.

With fresh oil we let them idle for a few minutes and load them with the stall converter to about 4,000RPM several times. Go to neutral and throttle them to 5,000 or so. Once everyhting has settled, they go to the track and WOT to 8,200-8,500RPM 1/4 mile passes and live that way. No issues so far and no burn or scoring of any kind.

The same theory applies to these engines just the numbers are different. Try not to hold a steady speed for more than five or ten miles for the first 50-100 miles, change it by 10mph or so at different throttle ranges. Harsh downshifts are not a good idea though.

Heavy throttle launches aren't a bad thing at all, just don't push it to it's max for the first 50 miles or so. Chromoly rings will take a little longer to do everything listed, but not to much.

Save the synthetic until after the first 300 miles or so...


Ray
 
That isn't different from what I've always heard, it make slots of sense, and they even told me that when I bouhgt a new car several years ago.

The main thing is not to stay at a constant RPM.

While break-in is beign discussed, I have a couple of quesitons...

There is no "break in" procedure for our roller cam correct? We still want to use moly lube on the though, correct?

Also about valvesprings...
Compcams Webpage said:
11. It is important for new springs to take a heat set. Never abuse or run the engine at high RPM when the springs are new. Upon initial start-up, limit RPM to 1500 to 2000 until the temperature has reached operating levels. Shut off the engine and allow the springs to cool to room temperature. This usually will eliminate early breakage and prolong spring life. After the spring has been “broken-in”, it is common for it to lose a slight amount of pressure. Once this initial pressure loss occurs, the spring pressure should remain constant until the spring becomes overstressed. Then the springs must either be replaced or shimmed to the correct pressure.

What do ya'll think about that?
 
i did notice on my rebuild only about 5k miles ago that within the first 1000 - 1500miles the car was just a dog, try to drive it hard and it just had no pull. after some miles it started gettin up to speed
 
Back
Top