George, Suggestions for breaking in a new engine: 1. Use a quality straight 30 weight oil. Do not use a synthetic for the first few thousand miles. Synthetics are so slippery that they will prevent the rings from seating with the cylinder walls. Avoid oils with high paraffin wax contents. I can think of no reasons why a non-detergent oil would be better than a detergent oil, except that maybe 40 years ago detergent chemistries could not tolerate the heat and friction during break in. 2. Static time the engine so the timing will be close and the engine will run correctly immediately upon start up. 3. When the engine is fired for the first time, run it immediately at 2000 RPM for 20 minutes to break in the cam. After 20 minutes, fine tune the timing and carb. 4. Change the oil and the oil filter to remove the assembly lubes (some use solid particles that can clog the oil filter) and initial engine wear particles. 5. Drive moderately with varying engine RPM for 100 miles and change the oil again. Change the oil again at 500 miles. Gradually increasing short bursts with lots of throttle are OK if you keep the RPM low (under 3500). Second gear is good for this. More throttle gives higher gas pressures in the combustion chamber, forcing the rings against the walls for faster break in. 6. Add the oil you plan to use on a permanent basis. Drive at gradually increasing RPM limits until you reach your planned maximum RPM at around 2000 to 3000 miles. 7. Change oil again. Good luck, Dave Homstad 56 Dodge D500 -----Original Message----- From: George McKovich [SMTP:[email protected]] Sent: Monday, October 25, 1999 11:45 PM To: [email protected] Subject: [FWDLK] breaking-in new engine Hi all.... I will be installing a newly rebuilt engine a a 57 300C soon and remember years ago (in the 50's) many mechanics saying not to use a "detergent" oil during break-in, especially if you have chrome rings. What are you thoughts on this??? Also, what about a synthetic, like Mobil One or Castrol R ??? Any advice will likely be helpful. Thanks George McKovich Stanley, Idaho |