Metalhead,

I agree that the roller cam itself is not the issue from what I can tell from the literature but the fine metal powder and metal flakes that can contaminate the roller lifter bearing surfaces, not the cam surface that the lifter rolls on, during the first miles on a new or rebuilt engine. Agree on that point.

To the Rest,

The point of the breakin from what I can tell is to initially get as much of the fine metal powder from the new metal parts friction into a high Zinc oil as quickly as possible. The high Zinc breakin oil is used to protect sensitive bearing surfaces as much as possible during the first several minutes of the engine firing. The subsequent breakin miles which can number up to 1,000 miles are designed to allow the different metal parts to better mate to each other. My take, nothing more, others can do whatever the heck they want...I really do not care only to the point of dispelling some of the startup gospel...most of what I have presented is the procedures of what is in the literature, other builders and OEM manufacturers.......Saying that an engine that has a roller cam does not require any breakin is frankly not supported in the literature...period. Can it be done that way? Certainly but, MY OPINION, I would not ignore some sort of breakin procedures. MY OPINION!

The real question is why would anyone ignore most or any breakin procedure when it is really very easy, requires little additional money and potentially offers nothing but upside benefits? Why wouldn't one just to be prudent when doing so really has no downside?????...

Really folks????? makes me wonder..............hmmmmmmmmm

 

Might I go so far as to speculate that if you are using any kind of filter bypass that you are in fact more likely to introduce particulates to the rollers of the roller cam by using a cam break-in procedure that includes starting and maintaining a 2000 to 3000 rpm cam break-in procedure.
If the oil is room temperature and that room temperature is sufficiently low that the oil is still thick.
Then you immediately rev the engine to 2500+/-, RPM the chances that the bypass is open are significantly greater than if the engine is started, allowed to warm up to operating temperature, and then run hard to wear in the rings.

 

And OEM's have a far lower success rate than 100%. You don't have to look far to find many, many instances of problems with oil consumption on late model GM engines.

 

I think that is a fair point if the engine and breakin oil are cold....

When I first started my roller 355 in 2014, I used Driven Breakin oil, primed the oil with a drill for several minutes before firing and the outside air temp was 75-80 degrees. I am sure that the initial RPM's of 1,800-2,000 were not allowing the oil to by pass in the the oil filter....under those conditions

 

Cold is a relative condition. I believe that 75* to 80*F IS cold compared to operating temps of 180* to 212*. whether this is bypassing or not I cannot say. But I can say that until my engine gets pretty warm 150* or so, my oil pressure gauge is at 70 psi. Once warm 190*- 200*, it drops to about 40 psi at idle.
I know it's not evidence of bypassing, just evidence that the oil remains fairly thick until a relatively high temp, relative to room temperatures.

 

As the started of this thread I guess I'm going to just pretend I still have the flat tappet cam and follow that break in procedure. I'm going to run it about a half hour between 2000 and 2500 RPM with my Driven Break in oil. Drain it and change the filter, put in my Driven hotrod oil and drive it gently with some run ups to say 4000 or so. After 1000 miles, change the oil and filter then enjoy.

 

My math says that wouold be 3,000,000 revolutions of the crank.

So the question is, just how many cycles does it take to "break in" an engine?

 

This is ^^^^^ the procedure I used for my L-82 355 with roller cam/AFR heads and 10.2:1 compression on startup and breakin in 2014 according to my builders direction.

I would add that you should take it out for drive after the 30 minute breakin (prime with a drill through the distributor before first firing) for a series of 2,000-4,000 RPM full throttle on the road using engine braking/vacuum (seats the rings) to slow from 4,000-4,500 RPM back to 2,000-I did 10 accelerations this way and then went home to change out the breakin oil.

I would run the conventional oil up to 500 miles driving gently, but varying the rpm. Change the oil/filter again at 500 miles (conventional oil) and then progressively work the revs up to the 1,000 mile mark. Change the oil/filter again at 1,000 miles (I would use a high Zinc synthetic, if you want at this point) and then let er rip.....

Others clearly would advise you differently ............Do what you think makes sense for you.......

5 driving seasons in with the L-82 355 and zero oil consumption and no blowby from the valve cover breather...zero....

 

I remember when I was riding motocross on the YZ125. One of the guys I rode with was on a KX125. Both 2 stroke bikes. when it came time to do a top end (a frequent event on two stroke racing bikes) I told him how to break it in. warm it up, go ride it hard not to over-rev but up there in the RPM range to include cycles decelerating hard through the gears then accelerating hard up through the gears.

He thought I was crazy and absolutely refused to use that procedure. Instead he followed the OEM break in procedure of gently breaking in the rings and over the course of 10 hours finally getting up to full RPM.

Well long story short after my top end, my YZ 125 out pulled, out accelerated and generally outperformed his KX in every aspect.
His had problems with bogging down in the turns or even just mildly soft dirt. He had to clutch the heck out of it to get it into the power band and it wouldn't jet properly.
Seating rings is seating rings. two stroke or 4 stroke.

After 10 hours we both did a compression check. His was down on compression 20% vs mine. All of his problems were due to his break-in procedure I told him. He refused to believe that.
So he rode it for another 25 hours that way, a boggy underpowered POS due to poor ring seal.
Typical top end change for a 125 would be around 25 hours. His needed changing sooner but he wouldn't do it. Come 25 hours mine was still running well and only down 5% on a compression check, so I kept running mine.

He changed his top end again. (piston and rings)
When his piston came out the skirt was so full of blowby that it was a brown black color all the way to the bottom of the skirt. It took considerable time to clean up the cylinder walls to be ready for a new ring set.
This time he conceded to try my break-in procedure. And low and behold it worked. Nothing blew up, like he though it would, no disaster to the engine ensued, it just ran like a raped ape. It jetted up nice and clean and pulled like a freight train compared to his previous top end and even compared to new (because he had followed the OEM break in procedure when it was new).
I contuniued to run my piston ring combo for another 35 hours, total 60 hours before it was down 10% on compression, the usual metric used to determine time for new top end.
My piston came out clean as a whistle. With only a barely discernible tan line between the two piston rings.

Moral of the story, If you want an engine with more blowby and less power...... break it in gently.

A single cylinder engine with marginal power highlights just what the difference is.

A V8 that really never is put to a test probably won't. Still doesn't excuse using a poor break in process.

 

10 C6Z06 broken in gently per GM breakin procedure and ZERO oil consumption.

2001 Pontiac Grand Prix owned since new with 3.1L V6 broken in according to GM procedure of no high revs for 1,000 miles AND 215,000 miles on motor with zero oil consumption between 5,000 mile oil change intervals. I have never added oil to this engine between oil change intervals and still cruise on the highway at 80-85 MPH even today with the high mileage....with ZERO oil consumption..Hmmmmmmm

This ^^^^ is GM's breakin process, NOT mine............talk to GM.

 

You do realize that the engines are run in and the rings seated at the factory before the cars go out the door don't you? The easy breakin procedure the factories give you is for the sloppy tolerances on mass produced engines as compared to hand built engine where every clearance is checked. The factories are just covering their asses and it has very little to do with how a properly built engine should be broken in.

I also don't understand why you are arguing with people who have successfully done this for livings all their lives when all you have done is have somebody build an engine for you. I'm not trying to put you down or disrespect you, just trying to give perspective.

Mike

 

Mike,

I am not arguing with you or anyone else on this thread. What I am doing is providing supporting counter information that does not necessarily align with the narrative of others on the forum/thread. Like most things these days, a dissenting opinion, mine, as well as supporting documentation of other sources that does not align with a certain think tank is incorrect or not tolerated. My patience on this topic is wearing thin so you can be assured that I will no longer post MY OPINION to this think tanks' thread on this subject or many others probably moving forward since discussion is frowned upon. Kind of sad but not surprised in today's world....I am not wasting any more of my time or energy on this topic...Everyone happy now? Good

You guys can all carry on now and spread the gospel.........For the future, some may try the approach that "I disagree and here is why but of course, you are entitled to your opinion and do what you want".

 

I suspect, and maybe it can be found out through google, that the OEM break in procedures have far more to do with the rest of the power train and not the engine. Also the manufacturer cannot predict how the vehicle will be treated prior to warranty expiration period and the break in period at least gives gears and bushings in the power train a chance to wear in. If they had the manpower and the time I'm sure each vehicle could go through a manufacturer sponsored brake in procedure thereby controlling how it is broken in.

Do you think aircraft have a break-in period in which it's restricted to less than full power or full authorization to maneuver and operate it's of it's design limitations. Of course not. Why? Because it has already been tested to it, then assembled in a precise manner. The engines are rated for full power the day they hit the line, they've been tested.
Cars could be the same but the manufacturers don't have the manpower to do so and it would be cost prohibitive.
The liability for not doing so is limited and passed on to the consumer. Limited by the warranty and the recommended break in procedure. Don't follow them and something goes wrong, it's not their fault.

 

Owners manual, 2017 Silverado. I love the first line.

 

JB, it's not that we are saying you are wrong, or maybe we are, but more importantly no compelling evidence has been presented by you that supports your assertion that a roller cam needs a break in period. If you can present some kind of logical or compelling physics that supports your assertion then we could explore that.
,Nothing in and OEM manual that includes a break in period for that car specifically says it's for the cam. So not compelling. The fact that you did a break in for your roller cam and nothing blew up is not compelling evidence either, as those of us arguing the contrary have not used a break in for the roller and also did not experience any cam related failures.
I posed the question as to why does a roller cam need a break in if you can take a roller lifter and place it on any other lobe of a cam or even another cam and carry on. And you did not respond to that question.
Clearly this is not possible with a flat tappet cam and for good reason. Each lifter has been worn into it's associated lobe on the cam and to move it is to risk it's not rotating under use properly thereby creating a potential severe wear issue for both the lifter and the cam lobe should it not continue to rotate as it must under use.
I've seen the reccomendations by the likes of summit on break in for the roller cam, just not why. I think this is simply a carry over from flat tappet days.
I looked at cam companies and none of them that had a cam break in procedure had one for roller cams.

Consider this:
http://www.badasscars.com/index.cfm/...prod/prd82.htm

 

It doesn't say what gear I need to be in and stay under 55MPH, so...second gear?

 

I think the bottom line is there are different situations that require different procedures. I had built a 468 Chevy with Edelbrock heads (performer rpm rectangle port) Howards hydraulic roller cam with their light weight lifters, and used KB hyper pistons. I like to build my stuff on the tight end of the scale (bearings, ring gap) we decided to yank this engine out of our 67 Camaro (engine had never been fired) and put it in our Bump to Pass roundy round car. After a conversation on the phone with the resident Jebby, he reminded me that Hyper pistons like to run hot, and increased ring gaps are needed. (oh crap)
our remedy for that was to put a class A motorhome radiator in the car with twin fans off a 2000 Camaro, and run it without a thermostat.
The break in was 15 minutes of run time in the garage at maximum oil pressure so no specific RPM, just enough above idle to have maximum oil pressure with some revving of the engine with no load.
Track day was 5 laps moderate throttle, and RPM in practice, we run in low gear 1/4 mile paved oval with banked turns. Then Qualifying 2 laps as fast as I could go 6300 on the strait aways.
Edit I also don't run those stupid bronze distributor gears that fail every time (I have never had a problem with a stock gear on a roller cam) and I run a stock volume oil pump set at 60 psi max cold. Hi volume pumps just suck the pan dry.
Qualified good and made the 4 lap trophy dash, so 4 laps as hard as I could go.
Heat race usually 8-10 laps as hard as I could go which is full throttle tap tap tap the brakes, moderate throttle in the corners, and roll the gas on as fast as possible to WOT (too fast on the gas and it smokes the tires)
Main event 15-20 laps same as heat race.
I did not run break in oil, and the water temp never got over 140, I ran Schaeffers 5-w-40 Diesel synthetic, and changed just the filter after the first race, and only changed the oil one other time during the season (20 races) This engine is the tightest driest engine you will ever see, and the oil pressure is as good now as the first day, and as some of you that race know, the oil gets super hot.

 

w/reef, 1974 has come and gone. Dont kill or baby it, will be just fine.
If its gonna come apart it will happen at high rpm or even idle.

Lugging is imo worse than anything, seems to be an obsession amongs certain owner groups. Let it sing...your thrust bearing will thank you

 

Your Corvette is still one of my favorites