ok i had to install new pistons,rings,rod bearing and lifters into my heeps motor. due to a broken piston skirt. i need to know what is the proper way to break the engine in. i have searched and can not find anything. please help motor is going back in on friday. and going to be starting it on saturday




97 xj 4.o

 

get it up to temp (check for leaks)and take it for a drive for about 20 miles taking it easy when getting up to speed and then vary the speed for a few miles....the key is to get it up to operating temp for awhile (at least 20 miles) then after 50 or so miles drive it like you would normaly...I personaly change the oil after the first 500 miles to get rid of any metal shavings that MAY arise from the break in period...dont use syntheic for a couple of changes...
cameron
on edit...keep an eagle eye on those gauges during this time...it may run hotter then normal in the begining then settle down after some miles are put on

 

ok thank you! and i plan on changeing the oil at 500 and at 1000 just to make sure im good to go. also just 10w30 good to use as break in oil

 

that is a decent weight...if you for sure are going to change it at 500 and it is not too cold out there then go with a straight 30 weight at first if you can...I just like a straight high detergent oil at first....by the way...pick a brand of oil and stick with it...I prefer valvoline and Shell rotella...I use Rotella in my Cummins,flathead and the XJ...I use valvoline in everything else...
Cameron

 

go to a local machine shop(some parts stores may have it) and pick up a few ounces of zinc additive. add this to the oil before you start.

make sure all fluids are good and topped off
prime oil pump via distributor hole
fire up motor
lock idle into place between 1900-2000rpms
run the motor at that speed for 20 mins.
pay very close attention to the temp while doing this, do not let it get to hot

after the 20 mins, shut it down and let cool off.
check coolant and top off.

start back up and go drive
slowly run up through the rpms in each gear (no more than 50% throttle)
occasionally let off the gas and let the engine compression slow you down without hitting the brakes.
do this for 15-20 mins

then, just drive how you would normally drive for the next 500miles

change oil

 

While building my stroker a few years back i did a lot of research and spoke to my machinest about it at length. What I learned was that improper break-in can most definetly shorten the life of any motor.

Fill motor with Chevron Delo 400 (Contains high level of ZDDP)
PRIME THE OIL PUMP!!!!!
Start the motor, if it does not start imediately....STOP!!
Continious cranking will wipe all of the cam lube and assembly grease off the rotating parts.
Once the motor starts, immediately raise the RPM's to 1800 and keep it there for 20 minutes.
Shut the motor off and drain the oil and remove the filter.
Fill with fresh Delo400 and a new filter.

You're good to go after that.

 

They make oil for proper break in for an engine,try and asking a pro about it first cause I see some miss information here.Some good info above.

 

the additive is fine, you dont "need" a special kind of oil for break in.

do explain this "miss information"

and by all definitions i am a profesional

 

When you prime the oil pump do it with the valve cover off to verify oil is coming out everywhere its supposed to. Either the oil or the additive is fine you need the ZDDP for the cam/lifter break in. It may be wise to check your injectors first make sure none are sticking it will wash the cylinders down.