Alternate method of engine break in.

[gmakra]

I finished my stroker a couple years ago and I had some help from a friend who used to work at Chrysler designing engines. He suggested a custom grind for my camshaft and we got on the subject of cam failures. We talked about nitrating and he said it wasn't as effective as people believe. It doesn't hurt but it's not all that effective. He said proper break-in was the key.

He said he uses a slightly different method of breaking in a camshaft and had been doing it for years and never has lost a motor with this method.

His method is to start the engine and take it up to around 2000 RPM for about five seconds then shut off the engine and let it cool completely to ambient air temp. The next time he starts the engine he runs it for about 10 seconds shuts it off and lets it cool completely. Each time he starts the engine and lets it run for double the time of the previous run. He does this on-off cycling till he gets the full 20 minutes. In the end you actually end up with a lot more than 20 minutes of break-in time. He also said that there were metallurgical benefits to breaking in an engine this way.

I tried this method and it worked very well and there are some side benefits to it. It gives you time to correct problems before they become catastrophes. Say you find a small water leak or oil leak you can fix it in between run cycles.

I have broken in engines both ways and I have to say I prefer the above method instead of running around like an idiot worrying about glowing headers, oil leaks and that kind of stuff.

Anyway it's food for thought.

[SilverXJ]

I would definitely not do it that way, nor would I recommend it to anyone else. 1) The engine won't be run long enough to get the air out of the oil system while under pressure, 2) Part of that 20-30 minutes is to get the oil up to temp, no way is it getting any where near temp using that method, 3) The metal parts must also get up to temp for a proper break in, 4) 5 - 10 second sit not nearly enough time to give a good coating of oil sling on the cam and piston walls. 5) letting it cool down fully is a good way to ensure cold, rich starts every time.

Getting the oil up to temperature as well as the parts is a major component to the reason for the 20+ minutes of break in.

As for the problems, take care of any leaks before hand or take a short break during the correct break in to check. Glowing headers is normal. Put a fan on them or turn on the e-fan first if you are concerned. Coolant leaks are easily found prior with a pressure tested which you can rent.

This is just a bad idea.

[6TIME]

It doesn't sound like a good idea in my mind either... Alot of wear can occur in a new engine at startup when things are cold and there's no oil pressure present... If/when this wear occurs, it will set the stage for what the lifespan of your freshly rebuilt motor will be. In a new engine with tight bearing clearances and cam/lifter surfaces needing to seat, the best thing in my mind would be to start it, get oil pressure to the system immediately and get it up to proper temp while breaking the cam in... Intentionally starting a fresh motor numerous times before ever getting it up to temp seems very counterproductive.

[gmakra]

Gents I understand your reluctance; however there are some points to ponder. On breaking in an engine the cam shaft is by far the most critical, then seating of the rings and finally the matting of the rest of the engine components.
A camshaft is made of chilled cast iron and the lifters are case hardened steel; two dissimilar metals. The lifters bottoms have a slight rocker meaning that they are not completely flat. The camshaft when ground is completely flat across the face of the lobe. Now my understanding of breaking in a cam is that the lifter is to rotate in the bore so that the final action is similar in motion roughly to a ring and pinon gear. Meaning the lifter rotates against the face of the camshaft or walks around the lobe this is done to reduce friction. So when you are breaking in the camshaft you are more or less machining or lapping the lobe to the bottom of the lifter and this is were the break in oil is supposed to help out with the Zinc and Phosphors in the oil.

The idea is to on a gradient introduce the engine components to thermal expansion and contraction and there is some engineering precedent to this idea. A ring and pinon gear set is to be broken in gradually till 500 miles are reached. Older Harley engines were to be run for short cycles at varying RPMs till 500 miles.

Silver I respectfully disagree to a point with your statements on the oil temp and pressure. A gear driven oil pump is a positive displacement pump so no matter at what RPM; you should still be pumping oil even at cranking speeds. Granted its not a lot but it is however flowing. My understanding of oil temp is you want it to get to around a 150 degrees so that particulate matter precipitates out of the oil other than that the viscosity and properties remains relatively unchanged.

As I said I have done it both ways and luckily I have never flattened a cam. I will tell you once I tried the above method I like it since I felt I had more control of the the break in. All the items that needed attention were taken care of by the time I got to the longer run cycles. I hated seeing my headers glow orange while worrying about what the insides of my engine looked like and that is a sickening feeling.

I started out with a Golen Stroker 8 years ago and its been through 3 evolution's I now run a 4.7 with a 0331 head and intake with a Weber Redline MPI with waste spark kit and have 15k miles on it.

Again I offer this as an alternate method of engine break in.

[SilverXJ]

There is nothing to be reluctant to, this is simply a very bad way to break in a cam.

The camshaft when ground is completely flat across the face of the lobe.

Wrong. The cam lobe also has an angle to it.

The idea is to on a gradient introduce the engine components to thermal expansion and contraction and there is some engineering precedent to this idea. A ring and pinon gear set is to be broken in gradually till 500 miles are reached. Older Harley engines were to be run for short cycles at varying RPMs till 500 miles

This isn't an old Harley using old engine oil. And its not a ring gear. Different procedures for different designs/times. Even then the ring gear gets hot during the breakin. Running the engine for 5 to 10 seconds is getting nothing hot enough to do any thermal cycling.

Silver I respectfully disagree to a point with your statements on the oil temp and pressure. A gear driven oil pump is a positive displacement pump so no matter at what RPM; you should still be pumping oil even at cranking speeds. Granted its not a lot but it is however flowing. My understanding of oil temp is you want it to get to around a 150 degrees so that particulate matter precipitates out of the oil other than that the viscosity and properties remains relatively unchanged.

1) The cam is splashed lube there is no direct oiling to it. You can put what ever sized oil pump in you like it won't help until you get the RPMs up to get the splash lube going. 2) Getting the oil up to temp has nothing to do with particulate matter and everything to do with the temp that the oil works best at, the higher weight of the 10w30. As well heating the parts up. 150* isn't hot enough for a cam breakin. More like 210* +. 3) You aren't touching either of those numbers with that break in method.

I felt I had more control of the the break in. All the items that needed attention were taken care of by the time I got to the longer run cycles. I hated seeing my headers glow orange while worrying about what the insides of my engine looked like and that is a sickening feeling.

There is no control. There is nothing getting hot. If you don't like seeing the headers glow, put it a fan on it or just don't do it.

Again I offer this as an alternate method of engine break in.

This is not a break in method. I don't know what it is.

[shawnxj]

i agree with silver this is about the worst method i've ever read for breaking in engines and i've broken in several dozen over the years

[Rinkrat456]

His method is to start the engine and take it up to around 2000 RPM for about five seconds then shut off the engine and let it cool completely to ambient air temp. The next time he starts the engine he runs it for about 10 seconds shuts it off and lets it cool completely. Each time he starts the engine and lets it run for double the time of the previous run. He does this on-off cycling till he gets the full 20 minutes. In the end you actually end up with a lot more than 20 minutes of break-in time. He also said that there were metallurgical benefits to breaking in an engine this way.

If I'm reading this right, perhaps the guys here are missing your full intention of how this process works...

Do you mean you're starting with 5 seconds, cooling down, then proceeding to 10 seconds, cooling down, then 20 seconds, cooling down, then 40 seconds, ...., then 1min 20 seconds, then 2min 40 seconds, then 5min 20 seconds, then 10min 40 seconds, then 21min 20 seconds? Cooling down completely to ambient air temp between engine runs?

If this is the case, I see what you mean about the engine breaking in for a lot longer than 20min...but still I don't agree this is the best method, as early on in the procedure the cam will be starved of oil for those first few runs and nothing will ever heat cycle.

[6TIME]

I could possibly see the thermal cycling theory being legit if it involved running the thing for at least minute or two.... But 5 seconds? The only thing that's thermal cycling in that amount of time is the header tubes.... As for the Ring and pinion cycling, Nobody goes and drives on their new ring and pinion set for 5 seconds. It's more like run it light for 5 or 10 miles then cool it off. There has to be a considerable amount heat involved to benefit from thermal cycling of any sort with iron/steel or it's basically accomplishing nothing.