breaking in an engine

[scottreallyknows]

I just got my new motor in the car and it started up today. I let it run for about 30 seconds and shut it off. I changed the oil and then I let it run for 5 min from 2 to 3 thousand rpms. Now I am going to change the oil again and then I am just not sure where to go from here. I heard you should drive it for 50 miles and make sure you are all over the rpm range, or just baby her for about 20 miles. What would you do in my situation?? Any help or advice would be great.

Thanks

[mikec]

Typical break-in procedures are provided by the engine builder - if you don't follow them you can void the warrantee. If you didn't get anything from the builder, then:

 

Use conventional oil - not synthetic - for the initial break-in.

 

1: Initial startup: start it and let it idle. Closely watch the temps, oil pressure, etc. Anything abnormal on the guages or abnormal sounds ==> shut down ASAP. Watch for oil/water leaks. Leave the radiator cap off... if you see a stream of bubbles or some discoloration ==> shut down.

 

2: if it seems okay, rev to about 2500 to 3000 RPM for 20 minutes to condition the camshaft lobes. Keep watching/listening to everything though.

 

3: Check the oil quality. Replace it if you want.

 

4: go for a short drive someplace where there is little traffic. Do a few 2nd gear 3/4 pedal accelerations (but don't let boost build up) to "seat" the rings - accel and then lift off in gear, no clutch.

 

5: now drive the car around a bit. For the first couple hundred miles try to avoid sticking at any single RPM when possible. Don't accel hard but don't be a total baby either. Check the oil & coolant levels every couple hundred miles.

 

6: At 1000 miles, change the oil and filter. Examine the oil if possible - any signs of metal bits/shavings? Any signs of bearing babbit material? If not, the engine is pretty much broken in; drive it as you want.

 

7: If you want to switch to synthetic oil, wait a little bit - maybe after 5000 miles or so.

 

mike c.

[Jonathan]

+1 what mikec said.

[Lusion972]

Use a sledge hammer...thats how I normally break things in

[TopDawg_43]

I drive the car around, watching all the gauges, for about a week with the WG actuator arm unhooked, so teh car will not boost.

 

It's real boring, but your motor will be strong for the long haul.

[emagdnim]

Throw it on the dyno.

[RWDAddict]

I've heard another way of doing it. The break it in how you plan on driving it method.

 

Follow steps 1-3 but when you start driving it. Drive it like you want to. If you plan on making it your drag car then do a ton of 0-80 runs, peel those tires, and do some high rpm decels. It's hard to say which way is the right way.

[Zack_Morris]

I have seen people break engines in both ways. I prefer the easy does it method. Can't say if one is really any better than the other. I plan on breaking mine in the same way TopDawg_43 says.

[Maxzillian]

I follow Mike's method to nearly a T, although after about 100 miles, I will boost the car up to 3 lbs a small number of times to make sure the rings are seated. After that it's a combination of easy and smooth driving with the occasional 0 psi acceleration until about 1000-1500 miles. I also make sure not to exceed 3500 rpm or so until about 500-800 miles. Even at that, I never fully rev the engine out until break in is done.

 

Thanks to my luck with bottom ends, I've been able to practice this on three engines so far. The first two looked great when the head was pulled off, the third is still running.

Edited May 1, 2008 by Maxzillian

[RWDAddict]

^^

 

So what happened with the first two engines?

[Maxzillian]

^^

 

So what happened with the first two engines?

 

The first one wore out a rod bearing due to a mis-sized rod end. I measured them, but apparently one slipped by me. Measure twice!

 

The second had everything resized, but the bearing clearance was about .002-.0025. It died after about 6000 miles after a few drag runs. I never determined if I was pulling oil away from the sump on launches or if the clearances caused the problem. Either way, the thrust bearing went to hell along with rod #4. It was difficult to tell which went first.

 

The third has a fresh crank ground .010 under and I had a local race engine builder do my short block.

[PDX87Starion]

this guy: http://www.mototuneusa.com/break_in_secrets.htm

 

Has a good case for the "hard" break in method.

 

He shows pics of pistons that had been broke in differently.

 

The gist is that you have a narrow window while the surfaces are ruff to seat the rings.

And you need cylinder pressure (full throttle) to push the rings out for a good seat.

 

Which ever way you go, I would keep the boost way down for a while to be safe.

 

Keep in mind crate engines and race engine are built and put on the dyno, and they dont baby it

for a day or two before they put the hammer down.

[emagdnim]

20 minutes is all it takes for the rings to seat, tops.

[RWDAddict]

Here's a good qoute from that site. PDX nice find :- )

 

"So why do all the owner's manuals say to take it easy for the first

thousand miles ???

 

This is a good question ...

 

 

--------------------------------------------------------------------------------

 

Q: What is the most common cause of engine problems ???

A: Failure to:

Warm the engine up completely before running it hard !!!

 

Q: What is the second most common cause of engine problems ???

A: An easy break in !!!

 

Because, when the rings don't seal well, the blow-by gasses contaminate the oil with acids and other harmful combustion by-products !!

 

Ironically, an "easy break in" is not at all what it seems. By trying to "protect" the engine, the exact opposite happens, as leaky rings continue to contaminate your engine oil for the rest of the life of your engine !!"

[Dad]

Drive it, warm it up good first , watch all gauges, drive it trying to vary your speed , not at a constant speed for very long.

 

Keep the radio OFF!!! listen to everything,

 

I boosted mine up to 7 lbs after about 100 miles, No need to baby it, but you have to be attentive to the engine.

 

Now if there is an issue like leaks, miss etc, that needs to be addressed right away.

 

Like Sam said the rings hook up in the first 20 mins.

 

Dad

[Whiplash]

I would follow Mikes advice.

 

But depends what type of rings. Cast rings, the OEM factory ones I think, are broken in easy. Upgraded rings, like Moly are broken in a little harder. Chrome rings, what most of us most likely have, should be broken in under about 66-75% load. Thats per Perfect-Circle rings.