I was just wondering what the brake-in period was for the 455 motors? My dad told me that he thought it was around 1000 miles before you should drive it over 50 MPH. My motor was a replacement motor, straight from Buick, when it was put in, but has sat with very minimal miles since 1981. I guess I should have asked this question before I started driving it huh? It's only got a little over 200 miles on it now, but I don't want to do anything to harm the motor any more than I might have already. I've had it up to 65-70 once or twice, but not for more than a few seconds. Thanks, Scott
I would break the cam in for about a half hour, then drive it for a few hundred without babying it, but without ripping out it's guts, on regular streets and on the highway, so that the engine sees a range of rpms during break-in. I broke mine in for 500 miles, then anything goes. After you break in the cam, change the oil and filter. Then go drive it. That's what they did when they were new... I feel that driving it around normally for a few hundred miles will give you a chance at identifying any nagging little issues...like the gas leak I had when I built my motor- bad pump.
your break in depends on the grit of the honing stone for the cyclinder walls, a steet engine should be done around a 320 grit and driven easy for about 250 miles if you want it to last. most race only motors are done between 400 @ 600 grit so a break in isn't a must, but the ring seal wont last as long.
