I recently rebuild a 97' 360 with some buddies and we are waiting for the exhaust to be put on so we can break it in, I hag heard so many different things, but the main things I have heard is to not run it hard under load, or to put it up to 4k right away. I've heard to run it at 2 grand for a half hour and to take it from 30 to 60, but a lot of the stuff I've heard contradicts the next thing I hear, but it all makes logical sense to me. Any helping hints?

 

Back in the days of non-roller lifters, CAM break-in was recommended to hold the engine at about 1500 RPM for 15 minutes or so..... You have roller lifters in your engine, so, that becomes unnecessary.

Your best bet is to just install the engine, make sure all fluids are good, burp the cooling system THOROUGHLY, and just drive it easy for about 500 miles. Change the oil, and do whatever you want. Do NOT use synthetic oil for break-in.

 

Curious as to why not using synthetic oil to break in an engine???

 

Synthetic oil doesn't allow parts to "wear in" like conventional oil does.

 

It's too slick. Your rings won't seat properly and you may end up with a skeeter beater. Check your oil frequently, like every time you stop the engine. The last engine I rebuilt used a quart of oil in the first 50 miles. Not a drop between oil changes for the next 25,000 miles until I sold the car.

Like others have said, change the initial oil at about 500 miles, don't hammer on the engine and vary the speed so you don't get a set speed for the rings. One thing I always did when rebuilding or putting a rebuilt engine is was get a couple of larger ceramic magnets. You can get them at the hardware store. Put one on the filter and one on the oil pan near the drain plug. This will catch and hold the small metal flash particles that come off machined parts. They won't catch aluminum flashing but the steel flash won't get pumped through the bearings. If the builder was careful, there may not be much. It's just a little extra care to get the engine right. The one comes off with the filter and you pull the one off the oil pan as you remove the drain plug. I have cut open the old filter for inspection and found metal by the magnet.

 

Thanks for the suggestion of the magnets. As I had never rebuilt a Magnum motor before, I was clueless and used Mobile1 10w30 synth. After reading this post, I went out and got 5qts of O'Rileys' house brand of 10w30 and added Lucas Oil Break-In-Additive (https://www.summitracing.com/nv/part...EaAmJqEALw_wcB) (REALLY wish Summit was open late Friday night when I had to get it) and a quart of motor flush from O'Rileys. I made sure the oil was topped off and ran the motor flush through the engine for 5 minutes and then drained the oil and changed the filter. I added the Lucas and the 10w30, put on the new filter then drove it gently for 50 miles. Drained and changed the filter and then used https://www.summitracing.com/parts/l...IaAjbEEALw_wcB. So far I have about 300 miles on it and it seems to be working great. Checked the oil last night and it is holding the correct level perfectly. Before it seemed like I was loosing a quart and a half every time I turned around. No sign of excess smoke nor leaks to be seen....

The question I have is this, when would it be safe to go back to 5w30 Mobile1 synth? We are supposed to be driving this 2000 Durango (yeah I know I'm in the Ram section, please don't hold that against me ) to Colorado on Sunday and giving it to my 25yr old son and his girlfriend. My original argument for using the synth in the engine was that it was able to go extended miles (about 7500 if memory serves correct) between changes...As he isn't the most dependable on maintenance (more into computer gaming) I wanted to make this as bullet proof as possible. Hoping to get about 500 miles on the Lucas break in oil before Sunday....any thoughts??

Thanks in advance

Steve

 

You can go to synthetic once you hit 500 miles

 

Awesome! Thanks for the fast reply I'm really going to have a hard time giving up this Durango...she's starting to grow on me and its 5.9 engine is just purring so nicely.

 

I sadly lost mine to cancer and they didn't make the body panels I needed. I do want to get another one, maybe a Shelby. No problem on the reply

 

That sucks about loosing yours to cancer...luckily we don't have that much of a problem with rust in Northern Nevada...and don't get me wrong I'm not giving up Durangos...I have 2 more (technically 3 but #3 is a parts carcass and 2wd) Both of my Durangos have the 4.7l engines ones a '00 and other is a '01...both are currently down the '00 had a timing chain passenger side failure an the '01 dropped #8 valve seat. So they will be back on the road as soon as the 5.9 is gone