[wnyzl11le]

It is crazy to me the amount of conflicting information when it comes to break-in a car. It is still winter here and my car won't be driven for a few months so I will make the decision when I finally get the car out.
Thanks or all the reply's!

[Stephen12ZL1]

read a break in procedure for a GM crate motor and you will realize most of these new car break in procedures are for items behind the engine.

[Stephen12ZL1]

https://www.chevrolet.com/content/da...e-19301326.pdf

[waterman]

Originally Posted by rlarsen462

You've GOT to get those rings properly seated and your window to do so is pretty small.

Roger that. Within 250-350 miles is what I was taught. It's ironic that GM does not publish a ring seating procedure for LT4/1, especially given the potential to glaze the cross hatching in the cylinder walls by improper seating.

Originally Posted by Stephen12ZL1

read a break in procedure for a GM crate motor and you will realize most of these new car break in procedures are for items behind the engine.

Agreed, are you thinking clutches and gear assy. in eLSD?

[wnyzl11le]

Originally Posted by waterman

Roger that. Within 250-350 miles is what I was taught. It's ironic that GM does not publish a ring seating procedure for LT4/1, especially given the potential to glaze the cross hatching in the cylinder walls by improper seating.



Agreed, are you thinking clutches and gear assy. in eLSD?

What is glaze the cross hatching mean? Never heard that before.

[Gunkk]

Here’s a (dry sump) lt4 breakin procedure, starting at the bottom of page 10, and basically the same as the ls3 Stephen posted above.

Remember, the GM warranty actuaries couldn’t care less if your rings don’t seat well and your engine is a few percent down on power or burns a little more oil.

But the engine experts at Chevy Performance probably do care. Take your pick who you want to believe: an accounting weasel or a high perf enthusiast...



https://www.chevrolet.com/content/da...mp-1932879.pdf

re: seating the rings.

It’s not explicitly mentioned, but steps 8 & 9 sure read like ring-seating instructions to me.

[wnyzl11le]

Originally Posted by Gunkk

Here’s a (dry sump) lt4 breakin procedure, starting at the bottom of page 9, and basically the same as the ls3 Stephen posted above.

Remember, the GM warranty actuaries couldn’t care less if your rings don’t seat well and your engine is a few percent down on power or burns a little more oil.

But the engine experts at Chevy Performance probably do care. Take your pick who you want to believe: an accounting weasel or a high perf enthusiast...



https://www.chevrolet.com/content/da...mp-1932879.pdf

True didn't think of it that way. Still do the 500/1500 correct?

[Gunkk]

Originally Posted by wnyzl11le

True didn't think of it that way. Still do the 500/1500 correct?

Oil changes: yes.
Keep it off the track and avoid WOT past 4k: yes if you still want to keep your warranty.

But that doesn’t mean you go easy on it for 1500 miles. I didn’t, but I also didn’t know about the crate engine breakin then: I wasn’t counting

My car’s oil was very black at 1000 and again at ~4000. Blackstone said the oil @ 4k was fine. Knowing what I know now I would have done the first change much sooner to get all the fine metal bits out. My car is now 5700 miles and doesn’t burn a drop, and it’s done a 3.7 0-60 on an unprepped surface bone stock, so take that for whatever it’s worth. I do my own changes with compliant oil and filters.

[Scottyz]

Iirc factory piston rings are likely cast rings. Any engines I built we used moly.
Regardless, all engines we built that went to an engine dyno went to full throttle.
Only sort of breakin was if we built an engine with a hydraulic flat tapped cam.

[Scottyz]

What I’m worried about is if I treat this car like the others, beat on it from new, then actually have a problem. The computers hold lots of info. If they would block me from warranty that would be a huge problem. So I can’t say I don’t worry about them looking at how many times I’ve gone over 4000 in the breakin period.

[Gunkk]

Originally Posted by wnyzl11le

What is glaze the cross hatching mean? Never heard that before.

read this:
https://www.enginebuildermag.com/201...the-right-way/

Originally Posted by Scottyz

What I’m worried about is if I treat this car like the others, beat on it from new, then actually have a problem. The computers hold lots of info. If they would block me from warranty that would be a huge problem. So I can’t say I don’t worry about them looking at how many times I’ve gone over 4000 in the breakin period.

You can very easily do the crate engine breakin (steps 7+ which starts upon taking delivery of a new car) while staying 100% compliant to the owner’s manual warranty requirements.

[Scottyz]

Originally Posted by Gunkk

read this:
https://www.enginebuildermag.com/201...the-right-way/



You can very easily do the crate engine breakin (steps 7+ which starts upon taking delivery of a new car) while staying 100% compliant to the owner’s manual warranty requirements.

I haven’t looked at your link yet. But I will.
I was playing with LS engines in 1996. Yes they were released in 97 in the Vette. We already knew the 4.8 would handle 1000hp pretty much stock with a turbo or 2 and obvious fuel system upgrades.
My cousin is an engineer for GM and helps in engine design. He was part of the I6 in the TB/Envoy, LS engines, eco tech and LT1/LT4 engines.
If I ask him how to break in my new car......I don’t even have to ask, I know his answer

[Stephen12ZL1]

Originally Posted by waterman

Roger that. Within 250-350 miles is what I was taught. It's ironic that GM does not publish a ring seating procedure for LT4/1, especially given the potential to glaze the cross hatching in the cylinder walls by improper seating.



Agreed, are you thinking clutches and gear assy. in eLSD?

yes, mostly manual transmission, eLSD, & rear gears. Clutch disc isn't a break in item IMHO.

[waterman]

Originally Posted by wnyzl11le

What is glaze the cross hatching mean? Never heard that before.

New cylinder walls are cross hatched (honed) to produce a rough surface that will help wear the piston rings in. Cross hatching creates peaks and valleys in the walls. The goal of properly seating the rings is to evenly wear the rings and walls so that the peaks of the cross hatch are rounded out. Yet deep enough to still allow the valleys to hold oil, so that the piston can hydroplane and avoid metal to metal contact.

An ultra conservative break in, including low ring pressure with constant RPMs does not allow the rings to expand enough to reduce the top of the cross hatch. Without proper seating occurring, the first episodes of WOT driving and high ring pressure, will find the peaks still angled and sharp. That in combination with high oil temp at WOT can oxidize the oil in the (excessively) deep valleys and "glaze" it into the cylinder wall. When this happens, the ring break-in process stops, and excessive oil consumption frequently occurs. The bad news is that extensive glazing can only be completely corrected by replacing the rings and rehoning the walls.

I believe that is what rlarsen462 meant by a small window.

Most people seem to operate on the philosophy that they can best get their money's worth from any mechanical device by treating it with great care. It's probably true, it is also important to define great care.

For those who still think that running the engine hard during break-in will ruin any shot at engine longevity, there is an argument for using high power loading for VERY SHORT periods (to avoid excessive heat) during the break-in between 250-350miles.

At the risk of redundancy, IMHO, the use of low power settings exclusively does not expand the piston rings enough, and a film of oil is left on the cylinder walls. Although it is reduced by the use of modern synthetic motor oils, the high temperatures in the combustion chamber combined with high ring pressure will oxidize this oil film so that it creates glazing of the cylinder walls.

Finding a happy medium where I'm pushing on the rings hard enough to wear rings and cross hatching in, but not hard enough to generate enough heat to cause premature wear and glazing is my personal goal for break in.

And of course staying within warranty guidelines.