I have a restomod 67 Fastback. Had a 351 Windsor installed and wasn't satisfied with the power so I had a new Jet Carb with new intake and a high performance CAM installed. After driving it about 200 miles It started burning oil and lots of exhaust smoke. Was advised to keep running for another 2K miles to see if the Moly rings would seat but still burned about 1 qt every 150 miles. Took it back and they found a bad hone job. They still charged me for labor since it was now considered a high performance engine with no warranty on labor. Still expensive tho. They re-honed it and new moly rings were installed. Got it back and it ran good with break-in oil for 300 miles. After the oil was changed it started smokin again so I took it back immediately and was again told the same thing. Run for awhile and see if the moly rings will seat. I told the mechanic to keep it and try and see if anything obvious was causing it. Now i'm getting mad and am about to tell them to either fix it or return my money. I don't want to do this cause this shop has a good reputation and I don't want to make things worse or ruin our relationship. But I've spent ALOT of money there! I'm not a mechanic and I don't know much so I am lookin for some advise.
You usually run an engine for about 3 thousand or so miles with the break-in oil before you change it. And, from what I know it takes about that long for rings to seat fully. But, it should not be burning a quart every 150 miles. I will assume the shop guarangees their work for a certain number of miles. If that is so, then just drive it to just about that many miles, and if it is still smoking and burning oil, take it back to them.
Thanks gingerstang. Everything I read indicates running for 1K to 2K miles and then see if there is still a exhaust smoke problem. I was surprised tho because there was no exhaust smoke while running it for about 400 miles with the break-in oil and as soon as the new synthetic oil was added it started smokin again. Guess I'll run it and see if there is actually any oil burning with the new hone job and new moly rings.
OK...This time, leave that break-in oil in there for about 3K miles, then change to synthetic. Get on the freeway, and exit every chance you get. You break an engine in by varying the RPM's a lot. By not going a constant speed, you accomplish that.
Agree with Ginger. Use break in oil until you feel the car is broken in and then synthetic. Most engine books say that. For me about 1,000 miles usually works, but there is nothing wrong with going with 3,000 miles if you change oil and filter once in awhile (after the first hour or two, then after another 500 miles and then every 1,000 miles or so after that. The theory is that the rings will seat better with dino oil. Synthetic is more slippery. Varying engine speed gets oil more places than just running at one engine speed, like hour after hour on the highway at the same speed. That's been my routine for a long time and it works for me.