tixeon

I just got my roller cammed 383 stroker motor running and am breaking it in. The rod brgs were a little on the tight side @ .0016/.0018. The techie from the stroker kit Co thought it would be OK and suggested running 5w30. I know that new vehicles have tighter tolerances and 5w30 is suggested in the owner manuals. This is be a DD that will never see a track, just some occasional spirited driving. Dave

cagotzmann

This is from GM for the ZZ383 engine break-in.

Caution
This engine assembly needs to be filled with oil and primed. You should add the specified oil (see start-up instructions)
to your new engine. Check the engine oil level on the dipstick and add accordingly.
Start-up and Break-in Procedures
1. After installing the engine, ensure the crankcase has been filled with 10w30 motor oil (non-synthetic) to the recom-mended oil fill level on the dipstick. Also check and fill as required any other necessary fluids such as coolant, power
steering fluid, etc.
2. The engine should be primed with oil prior to starting. Follow the instructions enclosed with the tool. To prime the
engine, first remove the distributor to allow access to the oil pump drive shaft. Note the position of the distributor
before removal. Install the oil priming tool, GM part number 12368084. Using a 1/2" dill motor, rotate the engine oil
priming tool clockwise for three minutes. While you are priming the engine, have someone else rotate the crankshaft
clockwise to supply oil throughout the engine and to all the bearing surfaces before the engine is initially started. This
is the sure way to get oil to the bearings before you start the engine for the first time. Also, prime the engine if it sits
for extended periods of time. Reinstall the distributor in the same orientation as it was removed.
After the engine has been installed in the vehicle, recheck the oil level and add oil as required. It is also good practice
to always recheck the ignition timing after removal and reinstallation of the distributor. See step 4 or engine specifi-cations for the proper timing information.
3. Safety first. If the vehicle is on the ground, be sure the emergency brake is set, the wheels are chocked and the car
cannot fall into gear. Verify everything is installed properly and nothing was missed.
4. Start the engine and adjust the initial timing. If using the HEI distributor P/N 93440806, set the ignition timing to 10º
before top dead center (BTDC) at 650 rpm with the vacuum advance line to the distributor disconnected and plugged.
This setting will produce 32º of total advance at wide-open throttle (WOT) when using the HEI distributor P/N 93440806.
The HEI vacuum advance canister should remain disconnected. This engine is designed to operate using only the
internal centrifugal advance to achieve the correct timing curve. Rotate the distributor counterclockwise to advance
the timing. Rotate the distributor clockwise to retard the timing.
5. When possible, you should always allow the engine to warm up prior to driving. It is a good practice to allow the oil
sump and water temperature to reach 180°F before towing heavy loads or performing hard acceleration runs.
6. Once the engine is warm, set the total advance timing to 32° at 4000 RPM.
7. The engine should be driven at varying loads and conditions for the first 30 miles or one hour without wide open throttle
(WOT) or sustained high RPM accelerations.
8. Run five or six medium throttle (50%) accelerations to about 4000 RPM and back to idle (0% throttle) in gear.
9. Run two or three hard throttle (WOT 100%) accelerations to about 4000 RPM and back to idle (0% throttle) in gear.
10. Change the oil and filter. Replace with 10w30 motor oil (non synthetic) and a PF25 AC Delco oil filter. Inspect the oil
and the oil filter for any foreign particles to ensure that the engine is functioning properly.
11. Drive the next 500 miles under normal conditions or 12 to 15 engine hours. Do not run the engine at its maximum
rated engine speed. Also, do not expose the engine to extended periods of high load.
12. Change the oil and filter. Again, inspect the oil and oil filter for any foreign particles to ensure that the engine is func-tioning properly.
13. Do not use synthetic oil for break-in. It would be suitable to use synthetic motor oil after the second recommended oil
change and mileage accumulation. In colder regions, a lower viscosity oil may be required for better flow character-istics.

doorgunner

That's a good checklist.
Since he already has the engine running....he needs to change the oil and filter according to the checklist to "catch any trash" and to keep new oil flowing on those bearings.

Happy driving and post some pics of the test drives!!!!!

AirBusPilot

I run 0w20 in my built 415ci w/o any issues. Plenty of oil pressure too.