I did a search, but all i found was break-in procedures for clutches.

I just ordered a new forged 382 ci short block. Id like some more opinions on proper break in procedures. This is motor is gonna see a lot of nitrous, and is being built for just that.

Break-in in general, how many miles? fluctuate the rpms? stay below a certain rpm, ***** to the wall right away?

How many miles before I can spray it?

I'm just curious on you alls past experience in this department, what has worked for you and what hasn't.

Thanks in advance.

 

two ways to break in any motor. ***** to the wall seems to get the most HP out of a combo but is short lived some times.
other way is to baby them for about 500 miles doing as you stated above. this usually sees a few hp less and longer life

 

Good luck getting a solid answer. Go with what your engine builder recomends. You ask this question here (which has been done a few times) and every time there's 15 different ways to break in your engine.

 

Do what you like, it all works. The manufacturers blast them on an engine dyno once and they're broken in. I've had two 436 strokers, one I babied for 1,000 miles and the other I went all out right after the first dyno run to tune it. There was absolutely NO difference in anything at all. Engines are broken in after there dyno runs. You're just seating the rings, nothing else matters.

I'm thinking there is no such thing as breaking in an engine. Build it, start it and drive it, thats all there is to it.

I would however do the oil changes at 100, 200, 500 and 1,000 miles. Just because there's gonnab e some metal shavings floating around in a new engine for the first 1,000 or so miles. And even after that.


.

 

What I've done is run for about half an hour steady get it up to a good operating temperature. Shut her down change the oil and filter. Put regular old dyno oil in it and drive it around for a bit. Bring it back change it again. Then new filter and refill with whatever your engine manufacture says. Like mentioned above motor is gonna have filings in it the first few times you run it. Gotta do your best to get most of it out.

 

Thanks to those who replied, the more opinions and educated advice the better.

 

Funny, I just read a Motor Trend article on this very subject about an hour ago.
According to MT the ***** to the walls method was from small motor low tolorence guys that had some good results by high ring pressures early on in the engine's life. MT talked to engine guys at GM and Ford and they said that in modern engines the tolorences are much tighter and the cylinder walls finished better. They do not recommend the B to W method and stated that any measureable gains would be argueable at best.

 

Well I have built some engines in my time and for some reason I always seem to have a leg up on the other guy. What do I do? I drive it easy for a little while.....not lugging it around everywhere but just not free revving it or getting it up very high in the rpms at all. I like to give it several heat cycles as well. Driving it a little bit the first day and then a complete cool down over nite is good.

For a LSX based engine I would keep it below 3k for a few hundred miles, short bursts of throttle around 50% or less will be ok. After the first few hundred miles progressively begin to let it rev out further, faster, and with more throttle. Around 500 miles or so you should have worked your way up to giving it full throttle and taking it though the entire operating range.

I feel that being easy on it during it's early stages of life will make it run stronger LONGER. I look at it like this. Every engine starts out tight, and making x amount of hp/tq. After it loosens up it will make more than before. It will continue to build power to a certain point, level off for a while, and then start to drop off. Sort of how a dyno chart looks. So to the people that say they make more power from the ***** out from the getgo.....maybe they reach that "peak" faster....but I bet it doesn't stay there as long as an engine done with my method or one similiar.

I also agree with the others about changing the fluids very often to remove the debris. That magnet on the drain plug will prolly need some cleaning as well.

Disclaimer: This is my .02, and I have had great results doing so, some people swear by the "break it in like your gonna drive it" method, others more so along the lines I have posted. It will be forever debated and to each his own. But there are my reasons supporting my belief. Good luck!

 

Thanks a lot for your post, i think this is definitley how I am going to approach the motor break in, i guess my next thing to decide is how long i will wait till i spray it.

 

I've always took it relatively easy and varied the rpms alot the first 500 miles. Get the oil to operating temp and go thru the gears from 2K to 5K rpms and let the engine rpms fall in each gear after reaching 5K rpms. I've found hilly terrain works best as you throttle up one side and let the engine hold you back down the other. My main experience is with Marine motors as my Dad used to build 392 Hemi's, Forged and non SBC and BBC's for watercraft. We used the same principles on the water as I said above except for the hills and we never had any problems. HTH

 

No problem at all, glad to help. If it were me I would wait at least 1k before I sprayed. N2O adds alot of extra heat and cylinder pressure. You can never be too safe. Good luck

 

Here's another opinion for ya. http://www.mototuneusa.com/break_in_secrets.htm

 

I followed the above post. Time will tell, 2500 on the motor now.

 

I've been told the same logic by a couple of engine builders as well
("soft" break-in)
No more than 3000 RPM's for the 1st 1000 miles
No more than 4000 RPM's for the next 1000 miles
Can be agressive but within reason for the next 1000
......have fun after that.

With the break-in miles, try to get in more city miles than highway.
If you're ****, change the oil right after your start up run/test.
Next, after 500, then 1000 and another 1000 - after that go to standard
durations.
Point of contrast - some suggest regular "dino" oil for break-in period while others say synthetic is fine......best to take the suggestion of the builder here, in case of any issue that may later "crop up".

*Keep an eye on oil pressure durring break-in period*

Good luck !

 

I have had no problems with mine. And I am about 600 miles in.

Ran to temp. Drained oil. AutoZone dino.
Drove car 50 miles. Drained oil. AutoZone dino.
Drove another 300 miles or so. Drained oil. AutoZone dino.
I figure I will change it again in about 500 more miles. This time I will switch over to Mobil 1.

I kept it REAL light on the first 300 miles.
Since then, slowly been giving it more abuse.
Up to WOT runs to close to redline. Haven't taken it all the way yet though.

 

thanks a lot for the replies.

this dino oil, is that the name brand of it? or are u all just refereing to really generic oil?

 

Cheapest regular you can find. I use the Wallmart SuperTech brand as it meets all API requirements and is only $1.08 or $5 for 5 qt jugs.

 

i always been told castrol

 

the link above is likely to be the best way to do it.

The way you SHOULD do it is how your motor builder says to do it, because they have your warranty

IMO, 3000 miles is excessive. In my SBC days, I drive it easy for 500 miles (dyno oil, not synthetic, that same stuff that prevents wear in your engine so well also prevents the piston rings from wearing to the cylinder walls properly). My next motor i'm doing as the link says (unless the builder doesn't like that!)

The machine shop that did my motor broke in his personal motor by planting the car against a tree and burning the back tires off

 

Fill it up with Regular oil, it helps the motor wear properly. Run it up to operating temp, change the oil and filter, get the shavings out. Run it up to operating temp again and blast it. Drive it for 300-500 miles with that oil and change it to synthetic...