evilemokid94

iTrader: (6)

can anyone tell me that correct break in process for a rebuilt motor? im hoping that later this week or weekend i will drop my fresh rebuilt 350 in and this is the first motor iv built and done so i dont know the correct procidures after i get it in and running, iv heard that i need to baby it for 500 miles and keep it below 4K rpm, but iv also heard putting it in, babying it for 500 miles but also beating on it alittle to help the break in process for the rings and bearings seat correctly, then change the oil after 500 miles and dont run synthtic till after like 1k miles. help?

t-top havoc

iTrader: (3)

Follow the cam manufacturers recommendations.
Change the oil & filter. Change again at 500 miles a couple times-- always look for signs of metal // grit.
Most keep RPMs around 2000-2500 for around 20 minutes... If timing is off or there are leaks, fix before restart.

88 5.7 Iroc-Z

Look it up on google, they have a few write-ups on it, the main things I remember were before starting it for the first time, you must add break in additive in the oil to keep from ruining the cam, and prime the oil system by spinning the oil pump shaft. Then once its started you gotta keep reving it to around 1500 for 20 mins, after that do an oil change.

evilemokid94

iTrader: (6)

I'm using a used lt1 cam

AvantiHall

I have a fire extinguisher and a have a heat gun, I pre oil the engine by filling with oil, filter pull the dist. And turn with drill, if no drill, i use a oil prime kit and feed it through the oil pressure sender hole, about 2 qt, then pour in balance. When I start the engine I have the timing light ready, I use the heat gun to check exhaust temperture. Most of the time they all go up the same, about 250 then settle in at about 425 degrees. If one goes up and up 600, 700 its too lean, shut off and fix before continuing. I watch everything, water, oil pressure, set timing, adjust carb, touch hoses and feel for poping, a hot spot in block. I usually run for a good hour without turning off, vary throttle 1200 rpm to 2500 rpm. I will also cause a vacuum leak at pcv hose to make it go lean, 3 to 5 seconds lesk,no leak for 3 minutes. it helps seat the rings. Recheck everything, and take for drive, be easy, accel easy and every 15 seconds to one minute let completely off the throttle to suck oil up to the rings. I drive it 25 to 30 miles and then park it for about an hour, recheck and drive about and hour varying throttle as discribed before. Ive broken in hundreds of engines. Max rpm is 3500 to 4000 for 500 miles, no full throttle. After 500 miles you can go higher rpm and full throttle but not extended periods. Change oil and filter be easy till 2000 miles change oil to full synthic and drive it. Remember lots of the new oil hurts the cam and lifters if not rollers. Thermostat is necessary, pre 1980 can be 160 after 1980 use 180 smog cars use 192. I'm breaking in another one tomorrow! Any missfire or problems turn off and repair. A good rule of thumb, if your pissing off people behind you (by varying your throttle) your doing it right!

Dave

InfernalVortex

iTrader: (4)

If youre using a roller cam all the cam break in stuff is completely irrelevant to you. Id still do the oil changes immediately after the first 15-30 minutes of running, and then 100-500 miles later, then 2000 miles later, then normal. But it's SO much less critical with a roller cam. Theres no metal grits from cam break in flowing through everything.

You can just turn it on and drive it to the store if you want. Not a big deal with a roller cam. Just watch oil pressure and temperature closely.