Hello all, I have a question...I have a stock 302 out of a 1983 Ford F150 4X4 that is going into the shop this week to get rebuilt. No upgrades on the cams, heads, etc...budget won't allow. my question is how do I break in the engine? The engine is being rebuilt in New Mexico, I live in Mississippi. I had planned on taking leave (I'm in the Army) and driving it back to MS. From what I have heard I cannot just jump in and drive 1100 miles back. Your advice would be greatly appreciated!

 

The shop isn't going to do the initial break in and start up for you? I'd call and talk to them about it first.

 

Break-in time usually is the first 500 miles. Use conventional oil (ie dino blend) and a good filter for the first 500 miles to catch any dirt or metal particles from the rebuild. Change oil and filter and go with what ever oil blend you want after that. Also dont drive hard during that time (meaning dont rev up to 6000 rpm). Besides that I believe there is some steps you want to take during the first start to make sure everything gets seated correctly. Please correct me if i am wrong on that. Call the shop rebuilding it and ask about that. There shouldnt be any reason they wouldnt know.

 

If he's got a flat-tappet cam, there are special break-in procedures and oil to be used. Ask the machinist, he should have the detailed procedures and can maybe even do it for you....

 

The critical time for the cam is when they first start it. People usually use some sort of moly grease or something that sticks to the cam. The problem is the cam is only oiled by splash, so the first "dry" start is when it will wipe it out. They do this for a living though, so that should be taken care of.

They also should take it out for a little break in procedure before they give it back to you. It depends on what style piston rings they use. If they use moly rings, these usually break in quickly and without much trouble. The chrome and other styles of rings may burn a little oil and be down on compression for the first few 100 miles.

What they usually do is get everything timed and buttoned up, then take it out on a deserted stretch of road and accelerate very hard for a short burst and then let off. They will let if slow down and then do this again, up to around 10 times. The hard acceleration creates a lot of pressure on top of the pistons, and this pressure presses the rings out hard against the cylinder walls, helping them conform to their new home. They do it in short burst to keep the heat down. If the engine gets too hot during the break in, the oil "cooks" or forms a glaze on the cylinder walls, and this hinders the rings from breaking in.

Like the others said, see what they say about the drive home. I would think they would recommend to take it easy and not work the engine too hard at the beginning of the trip.

 

I thought he said the old cam and valvetrane was staying in it? so he is just breaking in the rings and bearings.

 

Sorry I was somewhat vague...I am getting a complete rebuild with new parts (everything) just not "better" than the original, better meaning upgrade like better heads, cam etc.. Since I am 1100 miles away I had to pay someone to remove and replace the engine. The machine shop I am going thru is going to give him the first start oil and detail instructions on the cam break in. The machine shop advised me to drive around town for a few days, hopefully at least a hundred miles, change the oil and filter. He said by then the engine should be running very good. The trip back is two days, the first day slowly get up to about 55MPH, keep it there for 20 min or so watching the heat, down to about 45 for 20 min then back up doing this for about 3hrs. Stop and shut off until cool and do it again until I reach the 500 mile mark. Change the oil there and get up the next day and make sure its running good then get it up to 70 or 75 and see how it does, if it doesn't sound different or get hot its good to go. The shop has been in business for over 30 years....I just wanted to hear other people's way to make sure. Does this sound right?

 

Sounds right. Some of the new vehicles actually have a program in their computer that is more conservative for the first few hundred miles to help the engine break in.