I'm about to drop a 351w into my 67 coupe and I was hoping for advice on breaking in my new engine. I've done plenty of engine work on the 289 that's coming out, I've just never broken in a new block. Any advice is greatly appreciated.

 

Hey, let me know how that swap goes. I'm putting a 351w stroker (408) into my 67 coupe as soon as it gets finished, hopefully this week. Let me know what you learn...

 

Drive it normally for about 500 to 1000 miles then change the oil and filter. AT that time, put in synthetic oil. Never drive one speed for an extended period of time until she gets broken in, and don't stomp on it until after about 3-5K miles.

 

I would say to drive it for 500 to 1000 change the oil, stay with dino oil, drive it to 2000-2500 change oil again, this time to synthetic.

 

We break in engines by keeping it at 2,500 RPM's for 25-30 minutes. Check the oil for metal parts and if there isn't any then put it back in and drive it easily like the people above said and change the oil after a short time to get the metal shavings, and graphite and other things out of there.

 

just broke in my engine and the machiene shop gave me a pamphlet on it. run it at 2000-2500 for 20 minutes watching the oil pressure and temp gauges constantly. after the 15 minuted let it cool and change the oil. only use non synthetic. synthctic doesnt let your engine break in. then for about 700 miles take it easy on the engine. no red light racing no burnouts. i wouldnt take it over 3000 rpm. while your driving it take it on a highway or main road. accelerate decently to 55 then let of the gass . do this 7 times it breaks in the cam bearings. once youve reached 700 miles you can start to let loose. i wouldnt do it all at once but a burnout here and there wouldnt hurt. after its broken in set the redline to the lowest rpm of our of your parts. if your cam gives good power to 5500 then your redline is 5500. if it is around 7500 but your rods arnt that great or anything else is for any lower rpm then the lowest rpm is it

 

If you drive it for 500-1000 miles using dino oil at differing RPM's, the rings will be set. That is the only break-in you should be concerned about. At that time, I would put in synthetic oil. However, if you are unsure, then run it another 3K before adding the synthetic. At any rate, you should use synthetic oil as soon as you feel comfortable with when to start using it.