Break-In Procedures Per Manual.....???

Grumpy Bear · September 7, 2023

12 hours ago, Another JR said:

Not 10% past their yield load - 10% past their design load. At least that’s what it says. They still would have been below the fatigue limit (endurance limit) at the critical location if they designed it right because that would be one of the constraints that set the design. I assume that was what they were intending to demonstrate.

By IT do you mean this Peterson Publications book?

Fatigue limit - Wikipedia

Note "infinite" in this definition is based on the stress sustainable for at least 500 million cycles without a failure. That limit is UNDER the elastic onset stress. GM's test was 10% past the onset of the elastic limit. It's a range not a point on a curve. We've had the elastic plastic conversation, right?

Makes sense as rods under peak rpm absolutely 'stretch". OEM's use to use the tensile load encountered at 60 fps MEAN piston speed as the design stress limit meant to equal the elastic onset value. It is the reason there is a minimum piston to quench distance and it isn't the clearance stack up distance. Keeps the piston from kissing the head. Alloy rods stretch more so have a higher clearance value. Different from valve to piston clearance based on valve float rpm.

In the book when discussing the "Pink Rod" development it was made clear that even though GM tested the original rods past the yield limit, that consumers quickly surpassed those values and rod failures were chronic. (Pushed rpm to the plastic limit where cycle stresses are small numbers and yet below 'failure' stress or material proof stress".) 65 fps become the target.

Another JR · September 7, 2023

Hi Grumpy Bear. I was just reading what you had put in your post:

“When GM designed the first SBC the rods were built to take 110% of designed load at 6K rpm for one million cycles. It was considered infinite life. But what does it mean?”

In the next paragraph you then described the test load as 110% of yield, which seemed like a misinterpretation to me. Sorry if I read it wrong.

Grumpy Bear · September 7, 2023

22 hours ago, Another JR said:

Not 10% past their yield load - 10% past their design load. At least that’s what it says. They still would have been below the fatigue limit (endurance limit) at the critical location if they designed it right because that would be one of the constraints that set the design. I assume that was what they were intending to demonstrate.

Good catch! I corrected the text. Brain and mouth are having an argument. :crackup:

Dunn · September 7, 2023

On 9/5/2023 at 11:14 PM, Grumpy Bear said:

1.) When was it time? Point of reference for this statement is pivotal.

2.) How many is that and how many miles each, average. a.k.a how low has the bar been set.

3.) From GM Service Bulletin No.: 06-06-01-007H. It's a very low bar for a diesel. (below)

Duramax™ Life Expectancy The Duramax™ 6.6L V8 Turbo Diesel Engine is sold with a warranty of 100,000 miles/160,000 kilometers. The Duramax™ has been tested to survive upwards of 200,000 miles/320,000 kilometers. The Duramax™ powertrain is designed for reliability, peak horsepower and torque within its design limits......

Point to my last two post is POINTS OF REFERENCE. Not looking to pick a fight. But guys, if 150K is what you think a high bar is then do as you please. It will not have much impact on anything over such low expectations.

No diesel only gas, 250k when I sold them and were still running good.....4k mile intervals and first one I missed quite a few......I get it some dudes, oil is their "deal"........Like anything you can obsess til cows come home and people will....I do as well.......just not with oil

Never had a problem in 40yrs so no reason to think I will

Scratch that....my first baja bug I never changed it and it blew up on 405 (took forever to blow as well)......since then been good

Grumpy Bear · September 8, 2023

12 hours ago, Dunn said:

No diesel only gas, 250k when I sold them and were still running good.....4k mile intervals and first one I missed quite a few......I get it some dudes, oil is their "deal"........Like anything you can obsess til cows come home and people will....I do as well.......just not with oil

Never had a problem in 40yrs so no reason to think I will

Scratch that....my first baja bug I never changed it and it blew up on 405 (took forever to blow as well)......since then been good

So not a long OCI guy That tracks.

Grumpy Bear · September 8, 2023

23 hours ago, Dunn said:

No diesel only gas, 250k when I sold them and were still running good.....4k mile intervals and first one I missed quite a few......I get it some dudes, oil is their "deal"........Like anything you can obsess til cows come home and people will....I do as well.......just not with oil

Never had a problem in 40yrs so no reason to think I will

Scratch that....my first baja bug I never changed it and it blew up on 405 (took forever to blow as well)......since then been good

It is generally believed that 'problems' connected to oil maintenance are like walking off a cliff. If I don't fall off, it isn't a problem. 250K without problems is a really great feat. If that's your target....

I look at it more like a guy climbing a rope resting on a knife edge. Rope has thousands of strands, and they are being cut as I climb. If I'm down to the last strand when I make it to the top every time...I still have a problem.

This motor went 1 million miles. It's a short exposer but watch it when they show the lifter galley. And they gloss right over it. Need an ice cream scoop to clear that out. :crackup: But hey, went a million. Note how they try to convince you you're not seeing what you're seeing by repeating "how clean it is"

Another JR · September 8, 2023

The importance of break in procedures to ensure a good long term ring seal without destroying the honed cylinder surface, and the breaking in of the axle ring and pinion without causing damage that causes tooth surface spalling in the long run are one thing. The tendency of an engine design to collect sludge for various reasons is an entirely different issue.

Grumpy Bear · September 9, 2023

8 hours ago, Another JR said:

The importance of break in procedures to ensure a good long term ring seal without destroying the honed cylinder surface, and the breaking in of the axle ring and pinion without causing damage that causes tooth surface spalling in the long run are one thing. The tendency of an engine design to collect sludge for various reasons is an entirely different issue.

I see what you did there. Put the train back on the track. :crackup: Thank you

Ever see an automatic transmission collect sludge? Nope. Why not? No rings leaking combustion byproducts. Getting a good ring seal by careful break in and sludge; are about as connected as two things can be.

I showed the video, not to hammer the oil blender but to show that average Joe HAS NO IDEA what his leak down rate is nor does he care. If he's sitting on the limb he's cutting off, all he cares about is, "it did break' and because he stops sawing before it does, he concludes nothing at all was sawn. "Out of sight. Out of mind".

I've had Honda's run on OCI's of 7.5K and under 5% leak down have the oil look as good coming out as it did going in on the stick. (98 Honda HX I bought new and broke in on Red Line HP) I've had GM's with 35% leak down, turn the oil to ink in under a thousand. 64 Malibu 283 I bought used someone else broke in and broke out again.

Pepper has a TSB out on her for ring failures (build date 2014). I gave her a very careful break in. She uses none and leaks none. Under 10% even at 175K. I have no AFM issues or brake vacuum pump issues. (Both oil screen related BTW) Both oil related because? Careful break in limits sludge and I run a very polar oil and don't run it under 4 TBN to hold was does form.

IMHO; it is a mistake to compartmentalize functions when they act in concert. :dunno:

Another JR · September 9, 2023

I was thinking more about design issues other than serious blowby that cause deposits due to condensation. Bad ring design, improper assembly, or badly worn rings that cause a lot of blowby can cause sludge, but does an engine of an otherwise good design that uses some oil due to poor break in practices tend to have major sludge issues? I don’t have direct experience with this to know, and I appreciate being edumacated.

Edited September 9, 2023 by Another JR

Grumpy Bear · September 9, 2023

2 hours ago, Another JR said:

I was thinking more about design issues other than serious blowby that cause deposits due to condensation. Bad ring design, improper assembly, or badly worn rings that cause a lot of blowby can cause sludge, but does an engine of an otherwise good design that uses some oil due to poor break in practices tend to have major sludge issues? I don’t have direct experience with this to know, and I appreciate being edumacated.

Dad used to say, "Motor don't know what name is on the valve cover."

Oil doesn't know what the cause is. Bad design, bad seal of a good design. Leakage is leakage.

I suppose we could argue the definition of MAJOR

diyer2 · September 9, 2023

I change the oil on all new engines before the recommended miles, hours with small engines.

Sludge.............IMO

Occurs when oil isn't changed enough. Tired oil = sludge.

Grumpy Bear · September 9, 2023

11 hours ago, diyer2 said:

I change the oil on all new engines before the recommended miles, hours with small engines.

Sludge.............IMO

Occurs when oil isn't changed enough. Tired oil = sludge.

Which varies with how well the rings seal and how much load it sees. No universal value can be given. We use 'rules of thumb' based on experience and our pocketbooks.

Dunn · September 11, 2023

On 9/5/2023 at 11:14 PM, Grumpy Bear said:

1.) When was it time? Point of reference for this statement is pivotal.

2.) How many is that and how many miles each, average. a.k.a how low has the bar been set.

3.) From GM Service Bulletin No.: 06-06-01-007H. It's a very low bar for a diesel. (below)

Duramax™ Life Expectancy The Duramax™ 6.6L V8 Turbo Diesel Engine is sold with a warranty of 100,000 miles/160,000 kilometers. The Duramax™ has been tested to survive upwards of 200,000 miles/320,000 kilometers. The Duramax™ powertrain is designed for reliability, peak horsepower and torque within its design limits......

Point to my last two post is POINTS OF REFERENCE. Not looking to pick a fight. But guys, if 150K is what you think a high bar is then do as you please. It will not have much impact on anything over such low expectations.

250k and sold to a friend who got another 100k....other trucks have no idea

After 15yrs of owning a truck I am done....its not worth putting money into......1 million miles is insane...

Hell I doubt if most are even doing 150k and selling em

Point being simple oil changes will suffice for longer than most want or need a truck to last

We aren't shooting for Guinness worlds records

KARNUT · September 11, 2023

My brother in law drives Tahoes, Suburbans or full-size Chevy trucks. His wife drives them first then he drives them upwards of 300K miles. The truck that was recently traded in for a graduation present for his daughter had 280K was the only one he bought new. The rest were a couple years used at purchase. He currently drives a 2005 Tahoe to work with 280K it has weathered the best of all of them. Their recent purchase about 3 years ago a 2013 Tahoe. He follows the GM recommendations on services. The only recommendation I made to him was shortening his oil changes on the 13 that has cylinder deactivation to 5K miles. It’s nearing 150K miles. He has another truck a 2 door he bought used for one daughter for college. He likes it, plans to clean it up as his retirement ride. He bought her a new vehicle after she graduated from college. I’ve never seen any of his vehicles clean. Even though he is a car enthusiast. He still has his first a 69 Firebird convertible, he’s going to restore after retirement. The rest are depreciating assets to him. He does the minimum required disposes them when he’s finished. Funny neither daughter picked GM as their graduation present. He is eyeing a midsize next GM doesn’t have a rear drive midsize SUV, he may go to an explorer next. He won’t do a front drive vehicle.

nards444 · September 13, 2023

On 9/11/2023 at 1:06 AM, Dunn said:

250k and sold to a friend who got another 100k....other trucks have no idea

After 15yrs of owning a truck I am done....its not worth putting money into......1 million miles is insane...

Hell I doubt if most are even doing 150k and selling em

Point being simple oil changes will suffice for longer than most want or need a truck to last

We aren't shooting for Guinness worlds records

Thats where Im at. do what the book says and move on. Theres no empirical data saying doing it early or playing around does anything. Reality is americans dont keep cars past 12 years old, average age is more like 8-9. WIth average mileage being 12k a year, your talking 120k miles. A lot of that is for good reason. The motor its self is rarely the reason the car dies or its time to ditch it. Salt kills everything around it, trans, diffs, electronics etc. New cars often are cheaper insurance, more fuel efficient and some cost are offset that way. Also with newer cars electronics are expensive. You can have your 15 year old car that is worth 4k, but the dash goes out and its a 3k fix, not worth keeping it around.