Hi, im nearing the compleation of rebuilding my 87 f-150, 351w motor. im getting excited about finnaly being able to use my truck again, but have a question regarding the break in of the motor, This is what i have done, and im wondering how i should break it in. I re-ringed the motor, installed one new piston (old one had a ring trash it, but not the cylinder, thank the lord) new rod bearings, lapped valves (one new exhaust valve, for somereason the stem was worn short on one??) new oil pump. new fuel pump. now i know the fuel pump dosent need to break in. but what about the rest of it. I know with my 2 stroke stuff, snowmobiles and dirtbikes, you break it in like your gonna ride it, ex. if your gonna beat it, beat it durring brake in, if your gonna baby it baby it durring break in. but what about this truck motor. thanks in advance.

 

Use standard 10w30 motor oil, drive it for 500 miles (not over 55mph, and very the rpms a bit, but don't exceed like 4000rpms). Change the oil after 500 miles with whatever you are going to run it, then run the crap out of it if you like..

 

Ok, well i bought some cheap oil and a filter(dare I say supertech??), and planned on changing the oil in a few hundred, so i guess thats what ill do then Change back to the good oil and filter, although I got 10w40 instead but it should be fine. whats this motor supposed to run anyways, ive been running pennzoil 15w40 with a motorcraft filter, is this ok you think?

 

I gather you didn't install a new camshaft, so you don't have to worry about that. I perfer to run my truck longer than pfogle suggested, but thats just my opinion. I go between 1000 and 1500, but closer to 1000. It doesn't make a lot of difference either way. When you first start the truck, check for any life threatening leaks (coolant, oil, fuel). If there aren't any, go for a drive about 45 miles round trip, so the engine has lots of time to warm up. Stop every so often to check for leaks but DO NOT shut the engine off. Change your speed every 10 miles or so, going from 45 to 65 mph. When you shut the truck off for the first time you have to let it sit until the engine is completely cooled off. Overnight is best, that way the rings have a chance to set.

Now if you did change the camshaft, you need to break it in by running the engine around 3000rpm for 20 mins to 1/2 an hour. All the same rules apply as above, but use this time instead of a drive.

Hope this helps,

Trevor

 

yes it does, The only reason i was going to change the oil sooner was because of the metal filings, and dust, and the odball small peices of gasket that may have made there way into the oil. I have altready primed the oil pump and brought the intire oil system up to pressure, (using a drill, 3/8" socket and extention) and it dosent appear to have any leaks. the only thing im worried about is the multi peice cork oil pan gasket, but i put it in as per the instructions, so hopefully it will be fine. i probly should have used rubber. but, im orperating on limited funds. ill check back soon, im going to hopefully fire it up withing the next couple of days, i only have to do a few more things so i can fine time it and get it ready to go, but for now i need to see if someone has a vacume line diagram, the lines were all messed up from the day i bought it, so no better time than now to get them right.

 

I realize that, but the way it was said before I took to mean run it 500 miles, change the oil and your done. It's not that simple. If that is all your going to do the engine for a break in period it will not be as strong as it could be. Anyway, good luck with the vacuum lines, I can't help you out there, but a Haynes or Chilton manual should have them in it.

Trevor

 

I plan on following what you say, i think ill just drive around for a while and then let it cool down, it seems right, and sounds right, plus after being without if for a almost 3 months, ill want to drive it, oh and what about ideling?? can i let it sit and idel too or should that be avoided? thanks.

 

I don't think it would hurt it to idle for a bit, but I wouldn't let it idle for too long. Running into the store, talkin to a buddy on the street, or something like that won't hurt it, but I wouldn't let it sit idling for more than 15 minutes. I don't know how cold it gets in New Hampshire, but if it gets down to what I think it gets to (0 deg. F?)I would put some 5w30 or 0w30 in for the winter, just to help at startup. For the meantime keep it inside or put an oilpan heater on.

Trevor

 

The whole beat on snowmobile motor while break in....is I guess to set the rings in the cylinders.

My little RC truck w/ a small nitro motor (2 stroke) had an interesting break in procedure. They had you accelerate from a stop using 1/4 throttle for a tank of gas, then 1/2 throttle on a tank, then gently acclerate to 3/4 throttle for a tank, then fairly hard acceleration to 3/4 throttle for another tank, then smoothly to full throttle for another tank....just....acceration pulls until the tank was empty. I guess the principle is so that you can get better compression. More compression means more power...

I broke in my Arctic Cat last year using lots of varied throttle and I drove it for 20-30 miles before taking it to the fields and opening it up a bit. I was alil upset because the thing is so fast that I couldn't give it 2-3 second full throttle bursts until I was in a long field....but I just tried not to "stab" the throttle, always smooth applications of throttle. After I had about 50 miles on it I was giving it fairly long runs of near to full throttle...that thing screams!

It's hard to really say whats best....the people who've done it 1000 times w/ awesome equipment know it well....call up Vic Edlebrock

 

yeah right, ill get right on that, i talked to my proffesor at school today, he has built many a motor in his day, he told be just to go easy on it, no hard accelerations, keep it off the freeway for about 500 miles or so, so with all the experiance he has with domestics and those pricey imports, farraris and such,, i think ill do a long jont to start then go easy on it.

 

When I get mine going I'm going to break in the cam and then take it easy for a little bit, but I will be giving it full throttle runs similar to that RC truck break in....I feel it's good for compression and the bearings will be set by the time I wish to do this...thats just my preference I guess...

 

I was talking to my teacher about the cam break in, he didnt seem to agree with the 3,000 rpm for that long, is that actually what they want you to do to break one in?? If so id have to go find somewhere else to break in a cam if i ever do mine, my neighbors would have the cops here in no time at all, expecially if i had my truck cranking like that for half hour. its loud enough ideling, that you can already hear and feel it inside.

 

Mine says to break it in at 2000 RPM and I think it said 20 minutes, I'd have to check it again but I'm pretty sure it was 20 minutes. Since it's a brand new cam/engine...it should be done. If it were not a brand new cam it would have been fine not to break it in.

 

yeah i just thought 3000 sounded kinda high, but 2,000 not bad. at 3000 i would be grinding my teeth and pacing back and fourth for the 20 min.

i'll let you know how all turns out when my motors finnal broke in, i have a few mote things to put on then its gonna be time to fire it up. just gotta put the belts and accersories on, and exhaust y pipe.

 

Sounds great.