: New engine rebuilt breakin procedure

07-11-10, 08:39 AM
So. Gonna be breaking my engine in this month after new bearings and Jakes studswere installed this week. My mechanic told meto use straight sae30 oil. Then switch to synthetic after. What do I need to do. Here's my plan:

Oil and tranny fluid installed. Sae30
Crank engine for a minute to circulate oil with ignition disabled
Plug in wires. Start her up and let her idle. Avoid revving engine
Drive no more than 65 and cycle speeds for the first 3000 miles. I won't use cruise during this period of time during breakin.
Change oil after 3000 miles to 5w30 mobile 1 synthetic or valvoline synthetic

07-11-10, 09:19 AM
When your engine was born (2000+ ???) it was filled at the factory with GM 5W-30 bulk oil.

SAE30 transmission fluid ? - or DEXRON-III or -VI......dry sump transmission, so the engine must be idling in P to do a proper level check.

07-11-10, 09:35 AM
Haha. Yes. 99 sts. Dextron 4. I'll follow owners manual recommendations for the tranny I'm just validating what someonetold me to use. He said use straight 30 engine oil. If it had 5w30 straightoff the line then I'll use that. I just don't want to mess anything up.

07-11-10, 10:02 AM
Since the Northstar engine did not receive roller cam followers until the 2000 model year, your engine will benefit from the higher concentration of antiwear additives in Shell Rotella 10W-30 oil. I buy it in gallon jugs at Menards. You can also use Rotella 15W-40 oil. Mobil Delvac oil.

I wouldn't use straight 30 weight oil at all.

Vary the engine RPMs, don't redline it and don't drive at any one sustained speed for the first 500 miles. I would also change the oil and filter after 200-300 miles. Just use regular oil - synthetic is not needed or required.

07-11-10, 10:26 AM
Thanks. That's what I'll do. Never gone through a break inona car. Always bought dealer demos or whatever. Breakin was taken care of already. I wasn't planning on driving hard at all. I believe it will bevery reliable now. Ready to go home now and drop it in. :-)

07-11-10, 04:08 PM
Confused: Your login says 1999 but the mechanic says shift to a 5W-30 which is the 2000+ specified oil.

A 1999 IS NOT spec'd for 5W-30. If it is in fact a 1999, then it has flat tappet cam followers and KHE is exactly correct: your engine will run forever on a Rotella, Delo, or LongLife fleet/marine 10W-30 oil. (15W-40 is way too heavy for the tolerances in a Northstar; any Northstar.)

07-11-10, 04:19 PM
Thank u for the reply. I am not home to lookup the exact oil I. My owners manual. I will use 10w30. Sounds like a good plan. How many miles does breakin take? I plan now to change the oil after the first 500 miles. I think this is wise. I'd like this engine to last a long time and know the importance of proper breakin. Just want to ensure I do it right. Thanks for the comments!

07-11-10, 04:30 PM
IF the engine received a complete overhaul - rod and main bearings, pistons, rings, cylinder glaze-break (not really necessary), valve job, valve seals, cams, cam followers and maybe chains and slippers - then I would do a 1,000 mile oil/filter change.

On the other hand, if the engine was simply studded and reassembled then there are really NO new parts in the rotating assembly, so the engine is technically already "broken in" and you could go the the local dragway tomorrow morning with no worries.

As always, for the first 1,000 miles, keep a close eye on oil and coolant levels, belt tensions, and overall sound and performance. If the first paragraph is true, then drive the car moderately for a couple of hundred miles and then begin to load the engine progressively until you can do a foot-to-the-floor second gear standing start all the way to redline in 1 and 2. If the second paragraph applies, go out tomorrow and drive it like you stole it.

In any event, at your first oil change go to a WIX 51522 filter - more media, more filtration, less internal resistance.

EDIT: Read AJ's post - ^^^ - you don't want to idle an overhauled engine. Not good.

07-11-10, 04:33 PM
For ALL new engines

Use the recommended oil.
Use a Zinc additive. This is not necessary for 2000+, but still a goo idea
Crank the engine to build oil pressure. Plug out is the best way. Don't over heat the starter
Never shut off the engine after starting it until it reaches operating temp!
Start the engine and run it at 2000 as the engine warms up you can lower the RPM. When the engine reaches operating temp the engine should be idling on its own. This is to break in no roller cams. On roller cam you don't need to have the RPM's so high 1200 to 1500 is fine.
Drive the car and run it WOT 10 to 12 times through the RPM range. Say 20 to 60 mph depending on the gearing. This causes the rings to "seat" into the cylinder walls
Do not do anymore WOT runs until you change the oil. This should be at the 500 mile mark. The oil contains break in debris and you want it in the oil pan and filter not in the oil.

07-11-10, 04:51 PM
This is true. It got a partial overhaul. Ner mains and rod bearings though it didn't really need new bearings. I swapped my old cams into the lower mileage pressure tested heads. Had them cleaned and tested by a local machine shop to be in great condition. Got all new rings because water had been in engine and it had surface rust on the piston walls. The rings were no good so I opted for new. The original engine was seized. The original owner ran it out of oil. Was in bad condition. I put the lower mileage engine in because I got it at a steal. 250 engine and tranny. Ppl selling their blown head gasket engines around here by the dozen. It seems. Engine came out beautiful. Decided to go with my original tranny bc the gear ratios were different. The powertrain was from a Deville limo. Lol. 87000 miles

07-11-10, 04:53 PM
I apologize for the scattered thoughts. Hard to post from an iPhone. I'm offshore and have no Internet. Just my phone. :-(

07-11-10, 06:39 PM
You pluggin' an oil well or doing deliveries..............?........or dragging shrimp ?

Old 1600 Ton Steam & Motor Vessel Ocean Master (100 ton Aux Sail endorsement) here......renew for convenience now........

07-11-10, 06:54 PM
Haha. A little bit of all of it. Salvage mostly. Mapping pipelines and assist with platform removals and installations

07-11-10, 07:10 PM
LOL !!! During missile boat off-crews in Charleston in the 70's sailed part-time as 2nd on a 65 foot otterboard shrimp trawler out of Mt. Pleasant, SC - the GRAY GHOST.

Karen and I do large yacht deliveries now......but the pleasure boat business sux.

Ever run into a crew boat skipper out of Houma - Jim Denson ???? Lives in Marathon now......

07-11-10, 07:24 PM
I'm not sure. I do ride on a lot of crewboats. Mostly do work for chevron and such. Name doesn't ring a bell. Which boat? I don't get to talk to many crewboat captains. They mostly stay in the wheelhouse while I ride in the passenger area.

07-13-10, 11:23 AM
do you want to disable fuel only when first cranking a new motor to get oil pressure first without flooding motor with fuel? or will pulling the pcm fuse disable fuel delivery? i had lifter noise for several minutes but my heads were stored upright on end for several weeks during my headgasket job. assumed all oil had leaked out of lifters.