Hey guys finishing my 383 and wanted to know what are the tchniques you guys are using to break in your new motor.

 

Keep the revs over 1500 and less than 3000 for the first 500. Varying your RPMs. I.e. don't put it on 2 grnd and leave it for 500 miles straight.JMHO

 

I know he aint the only one knows how to break in a motor.

 

He basically got it. Make sure you have cast iron exhaust manifolds on there. I heard that breaking in an engine could mess up ceramic coated headers and warp non-coated headers. I could be wrong...but hey, couldn't hurt to try

 

Forget what he just said, and do what the other guy said. Just drive it around varying the rpms, and don't baby/lug the motor. for the first 500 miles.

 

WHAT???????? Screw up headers? Where did you hear that?

 

Before 500 miles:

Try not to exceed 55 mph for extended periods of time
Do not go on long trips and keep the car running at the same RPM, try to vary your RPMs
Do not do any hard launches on your car
Do not let the car sit idling for long periods of time
When starting the car cold, let it warm up a minute or so before accelerating hard
When you car hits 500 miles, you should probably change your oil. Most people stick with regular "dino" oil for the first oil change, but you want to change your oil very early to get the metal shavings out of your oil. If you're going to be doing this relatively quickly, putting in synthetic is a waste of money since it costs significantly more.

Once you hit the 500 mile marker, it's pretty safe to say your engine is as broken in as its going to get. The engine normally takes anywhere from 2000-6000 miles to fully break in, and thus give its best performance. People who test their engines with only a couple hundred of a thousand miles on it are often disappointed at their car's performance. If you vary your driving habits within the first few thousand miles, your car's engine will liven up relatively quickly.

 

chasman has it right

 

Historically break in periods and techniques were driven by camshafts (flat tappets need adaquate oiling achieved by higher than idel speeds for propper break-in) and rings (to ensure good seal), since our engines have roller lifters and most current rings are already borken in or "pre-lapped" to provide a good seal right out of the box the break-in requirements are not quite as critical.

Dino oil (historically non-detergent prefered) is better for the initial breakin period and avoiding idle for the first 15-20 minutes will ensure that enough oil is spread around.

One of the best things you can do however is to ensure everything is liberally coated with assembly lube during assembly,
If there is a way you should prelube your engine by driving the oil pump with a primer shaft driven by a drill motor (our engines don't have conventional distributors so I'm not sure how this can be accomplished)
Also I use a bottle of GM lubricating modifyer (AKA Whale Oil) and poor it all over the lifters, rockers and valves)

Check with your cam manufacturer for there recomendations
And the Header issue usualy has to do with not brreaking in coated headers on a new engine.

 

Thanks for the detailed posts guys. Hey I heard a lot about oils and grades. I'm already convinced that I'm going with dino oil and not synthetic. But as far as weight. I live in a warm climate and heard a lot of people just go with straight 30w oil. What do you guys think?

 

I used straight 30w to break in my cam/valvetrain. Just passed 300miles and going to get the oil changed to Mobil 10w-40syn.

With the 30w in 100* temps the Oil pressure never fell below 20psi at idle I think. Cant be sure on the accuracy of the stock gauge.

 

Never have I heard of anyone putting limited slip additive (whale oil) into the engine.
Not saying you can't do it, just that I have never heard of it.

 

This debate is a wonderful one. There is not a right and a wrong to this, it comes down to the hone used, rings etc. etc.

I put a motor in, and beat the hell out of it. Simple reason - back in the good ol' days when you rebuilt a motor you would use a very course hone. Today the hones are significatly finer thus leaving less abrasive surfaces to help seal the rings. If I would rebuilding a motor in 1974, I would give it 500 miles but now in days there isn't much, if any abrasive proporties left in the cylinder bore after 100 miles. Its like using 80 grit sand paper vs. 800. Some rings are softer than others, and this should also be taken into consideration when dealing with the break in peroid. With the stuff I use, you only have one chance.

This works wonderful on race motors, on a street motor you may not choose to use this method. To me its all personal preferance. Above is the reason why I do it the way that I do.

 

whats the deal with breaking in an engine with coated headers? never heard of anything like that before!

 

The main reason for a break in I have always considered...rings. If your rings to not seat correctly, the car will burn more oil and not run to its potential.

SO, what rings did you use. Chromoly and tool steel need no break in because they don't wear. Cast iron rings(which I used for the seal) you should get some good miles or hours of idling.

Something else not mentioned...header bolts..be on those things like flies on ****.

After about the first oil change, go over every bolt, within reason. Just looked the other day, 2 on my tranny pan bolts are MIA.