break in period for rebuilt motor

[cenok is family]

how many miles should i go before i lead foot my car? i'm totally rebuilding my motor with clevite 77 main and rod bearings, durabond cam bearings, power seal rings, all felpro gaskets and all ARP bolts. also what should i gap my plugs to? fairly stock motor, 308 with balanced internals, forged pistons, stock heads and cam, cobra intake, 65mm t/b, 80mm MAF, 24# injectors, full exhaust. thanks

 

[joncash]

500 miles at the minimum, 1000 if you can hold out. I lasted 500 miles D ) and didn't have any problems. Make sure to break it in w/ NON-synthetic oil.

Stock gap is .054, but I usually set mine at .044" to insure a good spark because I don't have an MSD box yet. Just make sure to use a good quality coil (MSD is a safe bet) and you'll be fine.

 

[cenok is family]

500 miles at the minimum, 1000 if you can hold out. I lasted 500 miles D ) and didn't have any problems. Make sure to break it in w/ NON-synthetic oil.

Stock gap is .054, but I usually set mine at .044" to insure a good spark because I don't have an MSD box yet. Just make sure to use a good quality coil (MSD is a safe bet) and you'll be fine.

cool...thanks for the quick reply. so do you think it'd be worth it to run synthetic oil AFTER i break it in? i was thinking about it but wasn't sure if it's worth it. i usually run 10w40 mobil regular.

 

[thumper460]

Syn oil rocks.. just get the 500 miles and go for it!! actually new cars have the syn oil in them NEW!!
Break it in like you are going to drive it!! You used good parts, have fun!!

Just me...........................

Thumper

 

[joncash]

There really is no disadvantage to running synthetic. The engine will stay cleaner internally, run cooler, and will last a lot longer-- especially if you plan on running it hard. My favorite thing, though, about synthetic is going longer between oil changes.

 

[jammer84_03]

do NOT run synthetic til at least your 3000 mile change!!!!! or else u can glaze a cylinder or the rings wont seal properly!!!

 

[jammer84_03]

*seat*....not seal

 

[87foxstang]

*seat*....not seal

yea i have heard that to..

as far as a disadvantage to synthetic, i guess the only thing is you cant switch back over to regular, the reasoning for that is beyond me

 

[ninety15.0]

When i broke in my motor i babied it for the first 500 miles ensuring to work the motor through the entire RPM range just using part throttle. Dont be afraid to let it rev...up to 4-4.5k and then also work in the low rpms as well. I started it on conventional oil did my first oil change at about 250 miles and put conventional in again. I did my second oil change at about 750 with conventional again. I did my 3rd oil change at about 2000 and switched over to mobil 1 synthetic and then started my normal regiment. Good luck and keep your foot out of it until at least 500 miles.

 

[smallstang393]

I lead footed mine coming out of the driveway (if it is going to break let it break now) and rings sealed great had no problems whatsoever motor ran like a champ and I ran it at wot for first 100 miles to break in

 

[millhouse]

I lead footed mine coming out of the driveway (if it is going to break let it break now) and rings sealed great had no problems whatsoever motor ran like a champ and I ran it at wot for first 100 miles to break in

That seems like the way it's done nowadays. Most engine builders recommend several high load WOT runs followed by high vacuum coasting immediately following. This is supposed to promote the best ring seal/breakin in today's engines. After 100 miles or so change the oil and filter and continue to give her hell.

 

[87Mustang351]

thats always been my motor, break it in like your going to drive it

never got to get around to a car motor yet, but i've done that on several dirthbike and snowmobile motors, they always seem to be faster that way too! haha

 

[cenok is family]

hmmm....so mash the gas out of the driveway ehh? muahahahhaa.....

 

[89LX347]

Ring Seating

When I put together my 347 I used Perfect Circle rings. I asked my engine parts supplier about ring seat time. (He is also a long time SBF engine builder) He said that the rings would seat within the first 5 minutes of runtime. Just food for thought....

 

[Black1987Stang]

When I put together my 347 I used Perfect Circle rings. I asked my engine parts supplier about ring seat time. (He is also a long time SBF engine builder) He said that the rings would seat within the first 5 minutes of runtime. Just food for thought....

and I believe it, just most people talk about break in like anything after 500 is ok but 499 miles would be bad, like there's a fine line between it being ok to get on it or not...... once I get a motor first started and up to operating temps, i do a bunch of high load pulls and decelerations..to seat the rings..the rings arent going to seat good if you baby it...in reality I think it's all seated in the first hour of driving. Just obviously don't use synthetics.

Somewhere there was a Really Good article and the guy made many good points on why not to baby it, and had pictures of 2 duplicate motors, one was by babying it and the other was doing it his way.....the piston skirt on the motor that was babied had blowby (piston ring leakage) since they didn't seat. I'm sure someone else has seen it, he made a website about it.

 

[allballsmustang]

ive always used the same process when i built and engines... first i heat cycle the engine 3 times at idle(run to operating temp, shut off, let cool to ambient). Once i do that three times i change the oil and filter, then run it like you drive it... have never had a problem... its all got to do with the parts you use and the machine work...if you work is good you wont have problems... ive drag raced on the engine i have in my stang now with less than 100 miles on it and that was last year...

jim

 

[Foxfan88]

when i rebuilt my engine, i just let it warm up idling, revved it up, drove it to the nearest back road, engine ran good, all was good so i layed into it, putting a load on it and took it to 5500 or so, let off the gas in gear, engine braking, with high vacuum until it got to low rpms... then did it all over again... did that about 10 times or so, let it cool off, changed the oil and then continued to drive it like normal. havent had any problems so far.

if the engine is going to fail its going to fail before shortly after you start it up....

 

[dcurtis]

It wasn't a ford but on the chevy 350 I built I had prolly 20 or 30 miles on it before I slammed the throttle to the floor, and it runs fine to this day, and I built it over 4 years ago, it is making over 400horses to the wheels if that matters. It doesn't smoke at all or burn oil or anything, it runs great.

 

[dcurtis]

ive always used the same process when i built and engines... first i heat cycle the engine 3 times at idle(run to operating temp, shut off, let cool to ambient). Once i do that three times i change the oil and filter, then run it like you drive it... have never had a problem... its all got to do with the parts you use and the machine work...if you work is good you wont have problems... ive drag raced on the engine i have in my stang now with less than 100 miles on it and that was last year...

jim

I agree, do this.