What is the best way to break-in a new crate engine?
I've heard 500 miles with no sudden acceleration, but is highway better than city driving? Should I mix it up?

Thanks

 

You should get a million different answers here! I would drive it normally without exceeding 3000 +/- RPM. Don't lug the engine and baby it TOO much. Fresh rings don't like to be lugged. Just be nice to it. Stay off the highway for extended periods of time, drop the oil and filter after 500-1000 miles and let'r have it!

 

Thanks for the reply. What is an extended period on the freeway? I have a 2 hour drive home on the freeway.

 

Run non synthetic motor oil for the first 200 miles, then drive it the way you normally do.

 

Run your standard Mobil1 synthetic ... it is a myth to run non-synthetic oil for break in (how did your brand new engine come from the factory ??? With synthetic for break in) .....

If you have a long freeway drive, just don't use cruise control during break in. You want to not run for long periods (say 30 minutes) at a constant RPM. By not using the cruise you will naturally have a varied speed so that will be fine.

With the tolerances in todays engines (unless yours is a "hand built" specialist engine) break in is just not that big a deal anymore. Back in the day ... engines were built with huge tolerances .... with todays computer controlled machining and manufacturing engines are built to much tighter tolerances which means they last much longer and are less susceptible to damage during break in.

For the first 1000 miles, don't put extreme stresses on the engine ... no running for long periods at or near redline .... no 1/4 mile drag strip runs ..... no heavy towing duties (oopppsss ... that's for your Silverado) ....

Otherwise, enjoy ....

 

with BlackZ06, and as Brain pointed out, you will find many opinions on this subject. I'll give you mine. First lets talk oil. If you wish to use other then Mobil 1 oil make sure you still use a good grade/brand. For me, I would use nothing less then Mobil 1. Guess what every new Corvette engine has in it for break in, Mobil 1.

The process of engine break-in has changed over the years. Many years back the cylinder bores had an extremely course finish. The was believed this was needed to allow the rings to wear into the bore for the best fit. It was also a belief that you needed to maintain higher load on the engine for the break-in to keep the most pressure on the ring to bore to help wear them in before the surfaces work harden. If not, the engine would always have high oil consumption.

Now, lets leap year to now-a-day. Dimensional tolerances of engine bores, pistons, bearings, etc...have improved dramatically from years gone by. The bore finish is extremely fine compared to past years. The one thing from the past that is still here today is which items in the engine go through the largest change during the break-in. It is still the piston and rings to bore. Breaking-in a new engine on a test cell dynamometer, the amount of blow by will decrease as the engine accumulates time and engine temperatures will decrease. The main thing that is used to determine when the engine is broken-in is motoring torque. After about every hour of break in the fuel is turned off and the dynamometer motors the engine. The amount of torque needed to rotate the engine is monitored and plotted. This value will be higher when the engine is first put into break-in and will continue to decrease with run time. The engine is considered broke-in once this motoring torque value stops changing. On current day engines this will take between 4 to 8 hours of run time, with most around the 4 hour mark. The idea of changing engine speeds and loads is still valid but taking days or weeks to baby the engine isn't really needed.

Regards,

Eric D

 

highway driving is fine, just vary your speed, don't use cruise control.

Put 500 miles on it not going over 4k or lugging it. Change oil filter after that then your fine to get on it. around 1000 miles change oil and put synthetic in it if your not running it already.


I have 600 miles on my new LS1 and autocrossed it this past weekend. It feels so good!

 

I agree with you 100%. When I had my motor built I ran it normally with synthetic. A lot of people and motor builder will still tell you to drive it easy to let the seals seat properly.

 

i just broke in my new ls6 crate motor. mobile1 syn in it, took it easy till the oil temp hit 170, then romped on it up to 5k and not higher. you need to drive the car hard to properly break in the rings. thats the only thing that needs breaking in. these are modern motors that don't need conventional oil during break in. at 500 miles i changed the oil and took her on a 700 mile round trip road trip and is like a champ. also got her dyno tuned at 500 miles for the cam i have in it. 427rwhp. cant complain with that. just drive it like you normally would and dont go above the recommended rpm

by no means am i saying wot on it whenever you can, but dont baby it. the rings seal the way you drive so when you baby it the seals seal to that driving style.

 

Some additional reading from the other side of the spectrum:

The type of fluid used during break-in is also important. You may have heard that synthetics are "too good" to use during the first miles on a new engine, and this is true. The main reason for this is the piston rings, which as we have said need time to seat to the cylinder walls properly; if they don't, horsepower and efficiency will be left on the table thanks to reduced cylinder pressures. Mark Chacon elaborates: "The ring face must have ample time to break in to the cylinder wall finish, and running a conventional oil for the first 1,500 miles or so will aid this. Ring seal needs to be firmly established before synthetic is introduced into the motor, and one of the reasons the factory LS1 has such a heck of a time with ring seal to begin with, in my view, is that many come from the factory with synthetic oil in them. Once you put synthetic in, what you've got is what you've got, and the rings may never really wear to the cylinder walls. Of course, feel free to eventually switch to synthetic because of its better properties, but make sure the rings have seated fully first; short of using a cylinder leakdown tester, mileage accumulation is the only way to tell whether this has occurred.

This is from the following and I hope the link is ok if not sorry and remove it:
http://www.gmhightechperformance.com...ild/index.html

My 383 was purposely built and not a create engine so conventional VR1 racing oil with ZDP containing zinc and phosphorus for break in.

Mark

 

This issue has been so :beatdeadh orse:

but just one more time ....

1) Even the makers of synthetic oil will admit that at normal engine temperatures a synthetic and a "refined" oil offer the same level of lubrication. A synthetic is not some "magic" oil that reduces wear over a refined oil at normal (between 180 and 240 degrees) temperatures. A synthetic is superior (does not break down) at high engine temperatures (like a Corvette engine can experience on the race track) and provides better lubrication for cold starts (fewer contaminants). Other than at the extremes, both oils provide similar lubrication.

2) If you are dumb enough to believe that a "refined" oil provides more wear at the piston rings, then how does it magically not allow similar wear at the crankshaft bearings, camshaft bearings, etc ....... it is some kinda "magic" oil that allows wear to the rings but no where else in the engine ???????

Stick with what GM recommends .... along with makers of virtually every other performance car out there ....... Audi, Acura, Mercedes, Bentley (and many others) ..... use Mobil1 synthetic for your break in.

 

You should ask this question to the shop that you bought the engine from. More than likely, you are getting a warranty with the new engine and need to follow their instructions to make sure they will honor the warranty if there is a problem.

FWIW, my engine builder told me not to drive at a constant rpm for the first 500 miles.

There was also a specific engine break in we had to do before even driving the car. Whoever installed your engine should be aware of the initial break-in process and should have completed it before you pick the car up. For my engine, this involved two 45 minute break-in periods allowing time in between these break-in periods for the engine to cool down, completely. The rpm was continually varied in these 45 minute sessions and did not exceed 4500 rpms. After the two 45 minute break-in periods, we drained the break-in oil (which was not synthetic) and replaced it with more break-in oil.

For my engine, synthetic oil was not recommended for the break-in. In fact, they recommended that I did not start running synthetic oil until 5,000 miles, to ensure proper ring seating. For break-in, TSP recommended Shell Rotella-T 15W40, Valvoline NSL Racing Oil 10W30, or Pennzoil 25W50 to make sure I there was enough ZDDP (anti-wear agent) for the break-in.

I used Rotella-T for the two 45 minute break-in sessions and then drained that and refilled for Rotella-T. I drove the car 1000 miles round trip to Texas Speed to get the car dyno tuned and checked over (engine was installed by a local mechanic that I trust). I didn't use the cruise control for the first 500 miles and continuously varied the mph by about 10 mph (5 below the speed limit to 5 above). After I got back from the 1000 mile trip. I drained the oil and went with Rotella-T for another 3000 miles. The next 3000 miles, I used Valvoline NSL Racing Oil 10W-30. From then on, I'm running Valvoline Synthetic Racing Oil 10W-30.

 

On a new Corvette, the engine is already broken in on an engine dyno, before being installed in the car. By the time the car got the factory Mobil 1 fill, it was already broken in.

My advise is to run whatever oil is recommended by the company responsible for the warranty. If they recommend synthetic after the initial break-in (done by the engine installer), then run synthetic.

 

Thanks to all of you for your input!

 

What engine setup are going with?

 

If your engine is built to similar tolerances as the factory engines, break in is not critical. As mentioned they are run on a dyno right off the assembly line. I think the owner 's manual still says just to vary the speed, and not drive long at a constant speed or high RPM for 500 miles.

 

Rob,

Are you suggesting that the new engines have something other then Mobil 1 in them on their first startup? Where did you hear the engines are dyno broke-in?

Eric D

 

I'm suggesting it is possible that the engines are broken in with something other than Mobil1. I don't know that for sure. I do know that the engines are not broken in at the Corvette assembly plant. They are already broken in when they arrive in Bowling Green. I had heard that before, but was told that again when I went on a tour of the Corvette Assembly Plant back in May. I got the VIP tour when my wife and I did Museum Delivery (R8C) on our '08.

They have Mobil1 in them the first time they are started at the end of the Corvette assembly line. I can't remember if they are filled with Mobil1 at the Corvette Assembly Plant or if that happens prior to shipping to Bowling Green. I seem to recall that they get filled at Corvette Assembly Plant.

 

I purchased a stock 405hp LS6 GM crate engine.
Thanks again for all of the help!

 

GM says that on the "hand-built" LS7 engines, Mobil 1 is used as an assembly lube, and that these engines are run for about 20 minutes (at Johnson Matthey Testing in Warren MI) before reaching the assembly line. I couldn't find any mention that the standard Corvette engines are run before going in the car.

The following is quoted from a "Vette Magazine" article (don't know how reliable they are) about a tour of the LS1 engine building facility :

"Interestingly, at the end of the production line, the LS1 engines aren't fired. They're filled with oil and spun to 2,000 rpm for "cold" testing, to ensure the oiling and coil-on-plug ignition systems work. They're then sent for some final balance checks, loaded into a shipping carrier, and sent to Kentucky. The first time they'll run is after they've been installed in a car."
ARTICLE IS HERE, SEE PAGE 2

It's interesting that the builder recommends against synthetic because it might keep the rings from seating, but recommends an oil with an uncommonly high amount of high-pressure anti-wear additive. Wouldn't this be as likely to keep the rings from seating?

I wonder if TSP also builds a lot of older style flat tappet engines. High levels of wear additives are important on these engines when first fired to prevent camshaft wear. This isn't a problem with roller lifters.

As Eric has mentioned, tolerances and machining are much better than they used to be. A friend of mine worked at a GM engine assembly plant about 30 years ago, and his job was "deburring" the cylinder walls before the pistons went in. He refused to call it "honing".