Yo what’s going on amazing people of ls1tech y’all are some life savers. Basically I got a 93k mile ls1 that spun a rod bearing and I jus got back the shortblock from the machine shop after getting new pistons and bearings/a rebuild. Basically my machine shop told me to use oem spec oil whatever it says to use in the owners manual and that for a break in period to put 500 HIGHWAY miles if possible… from what I know all new cars tell you not to put on highway miles for the first 500 miles but I’d like to know what you guys think? Dude at machine shop said constant rpm’s will help set the ring seals… thanks for any input and I still gotta get the long block together and the car back together but just thinking ahead.. thanks again.

 

Actually, the rings seat better with VARIED driving modes. The machinist is quite full of it....

 

On my all new build I used driven 5w30. And changed the oil and filter often. I also used Total Seal quickseat dry lubricant on the cylinder walls (mainly to verify bore cleanliness)
first start up and run was about 5 minutes to get things to operating temp let it cool down to room temperature.(lots of metal in filter) Then changed the oil and filter.
first drive was 25 miles rpm’s between idle and 4500 rpm’s loading the engine not holding a certain rpm to long. Let it cool to room temperature and changed the oil and filter.(less metal in filter still had some) Next drive was 50 miles varying the rpm’s idle to 6000 rpm hard pulls from 2500-6000 3 or 4 times rings should have been set at that point. Let it cool to room temperature and changed oil and filter.(less metal in the oil)Drove normal for 100 miles let it get room temperature changed the oil and filter (I had also installed a new TKX and Tilton clutch so I had break that in.) switched the oil from Driven 5w30 to Motul xcess 5w30 ran that about 200 miles and another oil/filter change at that point I had almost no visible metal in the filters. Changed oil drove 250 miles changed oil/filter,(almost no metal in filter) drove 500 miles rpms idle to 6500 rpms.
no metal visible in filter. I also changed the TKX oil when I replaced the engine oil. Expensive yes overkill maybe but cheaper then a engine and transmission. still haven’t raised the rev limit past 6500 haven’t had a reason to but will raise it to 7000 eventually.
Oil weights depends on what your bearings clearances and oil temperature runs at.

 

I still go by what this old website has to say: http://www.mototuneusa.com/break_in_secrets.htm

Basically, get the engine warmed up, then drive it like you stole it. You need to load the rings down to get them to seat best.

I don't know where this whole "baby it for 500+ miles" bullshit came from, but I've got this to say: If you didn't build it right, it's eventually going to break. Babying it is only going to push back the failure event.

Of course, this is assuming you AREN'T using a flat lifter cam, which has a much different break-in procedure... But then again, I don't know of anyone making flat lifter cams for LS engines...

EDIT: DO NOT use synthetic oil during the break in process. It lubricates a little too well, and keeps your rings from seating properly.
Just buy some cheap 5W30, beat the **** out of it for a few hundred miles, then change to synthetic and you'll be good with 5,000 mile oil changes.

Some guys I know (who do dirt track racing) swear by using non-detergent 30W air compressor oil for the break in period. I've never done that.

 

[QUOTE=dixiebandit69;20444862
Basically, get the engine warmed up, then drive it like you stole it. You need to load the rings down to get them to seat best.

[/QUOTE]

This.

 

In my 6.0. i used cheap regular oil the first 1k miles. started it up, let it warm up. changed the oil after it cooled. then drove 2 500 mile intervals. then switched to synthetic.
beat on it out the gate as well.

 

I'll second using non-detergent, 30 weight oil. It's not easy to find anymore. I just changed oil in my I.R. compressor. The compressor oil IS non-detergent oil, anti-foaming, and works well in a high moisture environment, but it's not cheap. Cheapest stuff I found was Porter Cable-1 gallon container@TSC for $50/gallon. Personally, I wouldn't use compressor oil, and, generally speaking, engines get a lot hotter than compressor heads. I'd look for 30 weight non detergent motor oil. It is still made, just not easy to find.

 

I would NOT recommend non-detergent oil. The detergent in oil keeps particulates in suspension in the oil, meaning it gets into your oil filter instead of staying in the engines moving parts. Non-detergent oils are used in engines and other systems like chain drives that don't have active oiling system explicitly because they don't keep particulates in suspension, but if you have a filtered pressurized oiling system you want the opposite.

When I start up my engine, it will be with a dedicated break-in oil, like Amsoil or Driven, get the engine close to operating temperature and if it is hitting on all cylinders it will be put under load.

 

Last 3 engines (400 Dart SBC, 383 LS1 & 416 LSA) zero issues breaking in with conventional oil (Valvoline). Definitely would use that or a break in oil. Ran briefly (a few minutes) with varying load and oil and filter change. Few hundred miles driving various loads then oil & filter change. Again at 1,000 miles. Conventional until ~2,500 to 3,000 miles then synthetic Mobile 1 etc.

 

The several I've done with dyno time have all been warmed up, set to 10% load for a bit.
First pull, shut down, check for leaks, maybe peek at the plugs, etc.
It's then "hammer time". 2 more full pulls, and they are done with break in.
Drop the oil, filter, refill when installing.

 

I'm basing my info on what my engine builders once told me, Kurt Urban, and Billy Briggs, who know as much, or more, than anyone you're likely to run into. They've literally built, or overseen, thousands of LS engines, and some builds include record holders. This was back when both worked at Wheel to Wheel, one of the most respected LS engine building companies in the world at that time. They used non-detergent 30 weight oil at start-up, and told me to change to a conventional motor oil at 300 miles, then to synthetic at 1,000 miles. The engine ended up with a leakdown rate of 4%, not too shabby, so non-detergent worked well for me.......

 

https://www.summitracing.com/parts/BPO-009-7120

What do you think this is? If you guessed non-detergent motor oil then you would be correct....

 

Being a good engine builder does not make you a physical chemist. The detergent breaks up particles and keeps them in suspension, and neutralizes acidic materials in the oil like carboxylic acids and soot.

Detergent does not hurt or inhibit things like ring break-in, which is the only break-in that we care about. These are all roller cam engines. Detergent in the oil is a small change and insignificant if the engine is built correctly. But if anyone on here puts compressor oil in their engine claiming to have found some speed secret I will laugh.

 

And when i say "changed the oil" i also changed the filter. that's just a given.

 

Chemistry, or rocket science, don't interest me. HUNDREDS of successful engine builds and dozens of national records, do. Wheel to Wheel was first in the 6s with an LS powered Camaro.....In 2007, 15 years ago!! Nothing succeeds like success. If they're getting reliability and National record power out of a V8, I don't care if they are running horse manure mixed with detergent, or non-detergent. If its good enough for them, its good enough for me. As I said, my engine had a 4% leakdown rate, which is damn good. If they were mixing horse manure with oil, and getting results like they have been, and still are, I'd be heading for the nearest horse farm, chemistry and rocket science be damned........

 

​​​​​​
The detergent content of your break in oil is a minor change, but you really shouldn't dismiss the hard science. When the nerds all get together and build something the results are things like the SR-71, which first flew in 1958.

A good example of how the nerds and their rocket science have helped you are your piston rings. A modern moly-faced ring is thinner, stronger, has less than half the drag of an old cast iron ring, and this is just free power.

 

https://www.amsoil.com/p/break-in-oil-sae-30-brk/

This will be what I use to break in the LS370 and then it's Amsoil Dominator 10W30 from there on out.

 

not sure what my bearing clearances are.. Im assuming stock but don't know much. I told the shop to go full stock as I just want to restore the car

 

My engine builder recommended this stuff:
https://drivenracingoil.com/i-304977...ak-in-oil.html

 

The Instructions my Long block came with said to use Non-synthetic 10w30 for the first 3000 miles. Lots of short pulls and variable throttle and NO sustained cruse for the first 300 miles then change oil.