Fred R. C4S

Over the years, I read a lot of posts from folks regarding the need for and nature of engine break in procedures on new cars and engines. So I thought I'd touch bases with a friend of mile who is the corporate subject matter expert for the Big Yellow Tractor Co. He oversees the rebuilding, testing and commissioning of remanufactured large Diesel engines used in mining equipment around the world. At one time or another, he has overseen the Component Rebuild Centers (CRC) of our largest dealers. Note that once these engines are delivered to the customer they are run at full load from as soon as they hiit the haul road. Here's what he had to say.

"When I first started out in my apprenticeship, all you ever heard was you need to run it in and everybody and his dog had some type of opinion and as you look back on the past, you did need to break the engine components in, as the machining tolerance / finish on crankshaft journals, bearings, piston rings, valve guides, you name it, were all over the map and it did require a break in period to knock off all the high spots, however, with the vast improvements over the years in machine tooling, that provide almost precision print spec and surface finish to all components and with the vast improvement in lubes the day of the break in, is history. Gone buried.

When I lived in Canada, I would buy a new car each year and within days, I was on the throttle as far as the pedal would go and the last car I bought was an 1986 Corvette and within two days driving out of Fort McMurray we almost hit 150 MPH and I was into that throttle anytime I took away from the lights and when I took it back to the dealership for the first check up, they even remarked how responsive this Vette was, compared to the other ones they had sold.

In my opinion when you break the engine in, it becomes lazy compared to one that is hammered out of the box..

When we fully rebuild any engine at the CRC, it will move to the dyno cell, where it will be started and run for approximately 15 minutes at low idle (no load) to check for any leaks and allow it to warm up to approximately 180F, then the engine speed will be increased to approximately 1500 RPM (no load) for five minutes then to high idle for another five minutes (no load) then after the five minutes the load is then gradually applied over 10 minutes to bring it down to the full load speed setting which typically is 1750 RPM and it will be held at this Full Load - Horsepower setting for approximately 30 minutes and after the 30 minutes further load is applied to bring it down to the full torque setting of approximately 1300 RPM for two minutes, then the load is gradually decreased to allow the engine to go back to high idle for a few minutes, then back to low idle for five or so minutes to cool down / stabilize before it is shut down, inspected and sent to the customer.

We have overtime tore down engines after the one hour or more dyno runs and you never see any signs of smearing of any components, that would lead to seizure after the rebuild. Machine tooling, print spec finish and lubes of today have eliminated the need for the extended break in schedule".

This fellow has been working in the specialist area for nearly 30 years. So he has seen things evolve over a long time. His word is good enough for me.

Macster

What a load of I don't know what.

All I can say is when your friend signs his name on the warranty guarantee for my new cars maybe his word will be good enough for me but until then...

SmokinGTS

Fred
Many years ago I flew new aircraft out the factory and was told by the engine reps to firewall the engines until you get to your destination. I took this same approach with my GTS and as a result have no oil consumption issues. I burn zero oil between oil changes and my car leaves no oil splatters on the floor at start up as my buddies C2S does. They don't break in race engines sans some dyno time that your engine also gets at the factory. Just make sure you are at operating temps before heavy acceleration.

CBejbl

Only anecdotal, but I hammered my GT3 from early on. Even after 2-day track events, it consumed zero oil.

Edgy01

How you break in these engines makes little difference these days. Things have come a long way because of material changes.

The reason I suggest this is because I have broken in my share of Porsche engines and each one ultimately behaves differently. My driving style is consistent, but the engines all vary. Much of the issue of oil consumption has to do with the tolerance stack--and not going easy during break in.

ADias

And the inconvenient fact that a slow revving diesel is radically different than a high revving gas engine.

kkswow12

tolerance stack...what is that, and do you mean that not going easy during break in results in no or less oil consumption...

Quadcammer

oh please.

Attorneys for porsche write the break in instructions. You think the engineers are sitting there thinking..."well, 1999 miles is just not enough to make sure the components are seated, lets make it 2000...how about 2001?....nein, dis is too much". No, they are out there and giving the cars full load and revs.

I've broken in a number of engines on the dyno. Few pulls to 50% of max revs, let the engine compression brake...few to 75%, compression brake, few to max revs, engine brake. change oil, check for leaks, and congrats, your engine was broken in. all delivered strong power for the combination (and we are talking 850 bhp) and had minimal oil consumption.

go ahead and baby your junk if you want to, but I certainly won't be.

Quadcammer

so all these moving parts have tolerances...I.E. ranges for bearing clearance, endplay, etc. Tolerance stack is the idea that these tolerances sort of build upon each other to develop into a loose or tight motor, which can have an effect on power output, longevity, etc.

Fred R. C4S

Actually, an inconvenient fact is that these large Diesel engines have such long strokes and heavy pistons their piston speeds and g loads often exceed what you have on your Porsche. You Porsche has a stroke measured in a very few inches, while these engines have stokes of over a foot. Pistons weights in pounds, not in ounces. They are really a lot higher tech them you are giving them credit for.

ADias

Diesel "Pistons weights in pounds, not in ounces". Precisely! Larger components are far more rugged.

ScorpionT

True. The attorneys just worry that someone might break parts, causing a warranty issue. I have owned many high performance cars and many of them get fresh builds for big turbo upgrades. Each and every single one I run hard off the bat and have zero issues with. The guys I see baby their cars are the ones who have issues with ring to cylinder wall sealing, bearings, valve seals, you name it.


True. Diesels rev low due to high piston speeds, which are similar to a high revving short stroke engines.

JohnInTexas

Thanks for the break-in discussion. I have two comments of semi-relevance. First, I once bought a brand new Toyota Camry V6 with something like 100 miles on it. I kept gas mileage records until I gave it to my brother with something like 240K miles on it. The gas mileage steadily increased from the first fill-up until about 60,000 miles when it finally leveled off. Maybe I would have saved some gas by breaking it in by driving it hard or maybe it's still going strong with no engine issues at over 315,000miles now because I was careful with it. The other note is Porsche-specific. I bought a 1989 928 S4 with 32,000 miles on it. I assume it still may not be fully broken in. Granted, it's a totally different vehicle but it's an interesting concept.

Fred R. C4S

I picked up my first 911 at the factory in Zuffenhausen in 1993. It was a 964 911C2. During the handover, I asked about any specific break in procedures or advice. As it relates to the engine, I was told not to exceed 5000rpm for the first 500 miles. That was pretty much it. I told the gentlemen that I had a DE at the Nurburgring in four days and asked his advice. he merely laughed and said drive 500 miles in the next four days.

I arrived at the track at just over 500 miles and left 3 days later with over 900 miles. In the next 35,000 miles I owned the car I probably added a total of two liters of oil between 5000 miles change intervals.

I often wondered as an engineer why a 500 mile break in was recommended in 1993 and today with better materials, machining, and tolerances, the period has grown to 2000 miles. Me thinks lawyers are involved.

Graygoose997

The fact that the US manuals always give break in instructions and the European versions do not, leads me to believe that break in is more about letting drivers get used to these cars before they hammer them, than it is about the mechanics of the engine.