Performance Engine Break-In

[TexasBronco]

I don't mean I just installed a cam. I had the entire 351C block rebuilt and..
Bored 30 over
Flat top pistons
Mild Cam
Edelbrock intake
Edelbrock carb
etc, etc, etc

The guy at the engine shop told me "we build the engine ready to drive...and...to drive it like you will under normal conditions" I told him it was going into a 4x4 and he chuckled and said "Never built an engine like this with that much power for a 4x4, just use your best judgements and take it slow for the first hundred miles or so"

What is a good break in period for a High Performance engine?
What are the do's and dont's or breaking in an engine?


Also have any of you used those things that mount inplace of the carb to install and engine? They use them all the time on Horsepower TV but I don't know if you can use them on an aluminum intake.

 

[2badrotties]

My last engine was a quick break in. I fired it up and let it run at fast idle ( around 2500 rpm ) for about 10 minutes. I shut it off, checked for leaks , fired it back up and watched the tack climb to 8500. I held it there for a few seconds and that was my break in period.
If a engine is built well 15 or 20 minutes at fast idle should be enough to break in the cam and do a good job of seating the rings. DO NOT break it in with synthetic oil. DO NOT let it slow idle before the cam breaks in unless you have a solid roller. After the first start up , changhe the oil and filter and drive it for a couple hundred miles before you really pound it.
Make sure the valves are adjusted close. Make sure you have enough water and oil in it. Best to do that first start up with exhaust so you can hear if something does go wrong. Have fun with it.

 

[wildbill]

;D ;D ;D I cant tell you what is right but the 351W in mine went 2 miles then with a chev next to us it went to red line in 1st and 2nd and about 4000 in 3rd and has been fine ever since that was over 95,000 miles ago and it is still going strong. Just DON'T babby it on it will run like crap. And since you said you did a C it will work in the uper RPM's I have one down stares .030 over erson double roller, TQ30 cam quenched heads 780 holly double pumper all the good stuff all new.%) %) %) Bill ;D %)

 

[Rustytruck]

First thing to do is the day you start it pull the dist and drive the pump with a drill motor so you know you have oil pressure and the filter is full. Then make sure you have someone to to start it while you screw with the gas and get the water system full make sure the gas tank is full. Start it up and get it to 2,000 rpm and keep it there for half an hour. Now drive it and drive it alot until you get 500 miles and then change the oil. The first half hour is the most critical and the most nerve wracking especially if the motor gets finickey. What ever you do dont run the motor rich in fuel fix the problem because it will waste the bore and rings in a very short period of time on a new motor. Ideling a new motor alot will greatly shorten piston/ring/bore life since the motor is cold and the pistons are tight to the bore and the only oiling they get is from splash oiling thrown from the crank. Not much oil gets thrown at idle speeds.

 

[Lance Lutke]

Why do you say not to break an engine in with synthetic oil? On a 5.0 HO from a mustang what cylinder did you all time the engine with the driverside timing marker?

Lance

 

[76Broncofromhell]

Synthetic is too slippery which means it doesn't let the rings seat in the cylinder bore. Regular oil lets it break in which usually involves going from 2100-2600 rpm for 20-30 minutes. You want to prime the oil pump first then fire it up. I would say drive it around and get it to 4500 every 30 mins of driving it, but only do it for just a second at most (my transmission will love it). Try and fluctuate the RPMs a lot, in other words let it go through the gears. Go for about 500 miles then change the oil. I would say the extended periods 4500+ rpm trips should wait past the 1000 mile mark. Also run a good 20W-50 like Castrol or Valvoline. Stay away from Quaker State or Pennzoil.

 

[raharr3]

I have used this to hold the weight of engine trans and t-case
with no problems yet.

 

[brutis72eb]

That is an AWESOME engine raharr3! I want mine to look like that when I decide what to get!;D

 

[Rustytruck]

Nice frame crease in the oil filter. Change that filter before you start it up.

 

[ballistic64]

Rustytrucks right the first thing to do when starting a new engine is to immediately take it up to 1500-2000 rpm to break the cam in

 

[iwlbcnu]

Just FYI, the cam break in is not nessacary on a roller cammed engine, but flat tappet it is a must, 2000-2500rpm 20-30 minutes.

I've always been told to break in with variable sppeds too, don't just take a 500 mile trip.

 

[SACHEM]

The Hot Rod shop up the street from my work buys allof our 30 weight lawn mower oild for break in purposes. I guess it is chaeap and has no additives at all. I always wondered if this was a good idea but they make some bad ass rides ao I guess they know what they are doing.

 

[iwlbcnu]

I've always heard to use 30w but never tried it.

 

[brutis72eb]

raharr-do you have anymore pics of the engine???

 

[Broncobowsher]

For me, I use name brand, nothing special oil. Keep the weight down so it will flow faster. Straight 30, 10w-30, 5w-30, ect.

After the engine is in and ready to fire, take out the distributor and spin the oil pump counterclockwise with a drill.

Drop in the distributor, fire it up and keep it around 2000 for about 20 minutes or as long as you can. Keep a hose ready as the engine will get hot and a little water over the radiator does wonders at cooling it off. Just set the timing at something that runs nicely. This is required for flatt tappet cams and good for the bores on all engines.

Retun to idle, set idle mixture and set timeing. Shut it off and let it cool. Recheck the header bolts, oil level, coolant, ect and take it around the block. sweep it through the RPM ranges and do some compression braking to suck some oil into the valve guides.

Get home and park it. Change the oil and drive it around. Keep the RPMs all over the place, but not to redline for at least the first 100 miles. If something comes apart, it is best to do it at less then redline. Don't baby it, but don't beat on it either. Keep dhecking the oil. New engines are thirsty until the rings seat.

After about 500 miles, another oil change again and use it. When the oil consumption slows down, the rings have seated. you may now switch to synthetic if so desired

 

[adambronco74]

What about for engines with hydraulic roller cams?

 

[2badrotties]

What about for engines with hydraulic roller cams?

All engines are pretty much the same BUT you don't need to be as concerned those first 15 minutes about keeping the idle up so the cam breaks in. As long as you have assembly lube on the hydraulic roller you won't have any problems. It is the softer " cast " cams such as a hydraulic flat tappet cam that wear out during break in if not done right.