I've heard so many, and I'm not sure which is right, some people say...

1) Don't redline in any gear for 1000miles, no matter what.
2) Don't drive in rain no matter what for 500 miles
3) Drive 250miles with no redlining, then redline a little bit to get the engine used to it.


ect ect..

What is the real NNA suggested break in, and what break in methods have you all used???

 

Never heard anything about no rain driving before, I dont think that hads anything to do with anything. Your option #1 is probably the best one, although it seems to be generally accepted to keep it under 4000 rpms for the first thousand miles, then you can start getting the revs higher until 1200 miles or so, and then you are good to go.

 

The one thing that has been the same for all the different procedures I have heard is: do not drive constant speed for a long period of time. I do fluctuate my speed if at all possible between 45-85. If I am in an area where the higher speeds are not possible (>70) i just shift between 5th and 6th every mile or so. This helps seat the rings, which has been a minor issue with the VQ motors.

About the redline . . . well sometimes I shift at 3K sometimes I shift at 4K and I have shifted at 5K a couple times. My rev light is set to 5K, I would not reline any new car, but there is no way I can always keep this baby under 4K for 1000-1200 miles. The one thing that make shifting early hard to do is the sound of that sweet note that fills the cabin as your RPM's grow.

Have fun and good luck!

 

this how we do race engines : run em up and down on the track from 3000 rpm to 5000 to 6000 rpm for about 30 minutes that seats the rings in , seating the rings in is really all you can do. The stuff about the bearings braking in and the valves is like this if the valve did not seal in the first place they are not going to seal afterwards , and you damn sure don't want your crank bearings or rod bearings to be scuffing the crank shaft so there is really no break in for the crank shaft stuff.

 

I say, go easy on the car for 500, no above 4000, no constant speeds. Then, next 500, introduce her gently to the top end. Then after about 1200 miles, really drive it like you normally would. No expert but seems right to ease her into place, and these engines are built in "one of the most advaned engine factories in the world" -(lust then love book) so they should be pretty resiliant to break-in procedures.

 

from all the posts Ive read, this procedure is not "general".

The only really procedure I trust is from raceboy, simply because of his proclaimed experience with his car and other cars at the track. But, I cant find what he said exactly anywhere...

jist: easy till 400 miles (under 4k rpm) then periodically inch towards higher rpms and redline maybe a couple times. Heat fluctuation being the most important and getting the pistons moving fast every once and while being second.

But...man...I wish we had an expert!

 

Well, I'l be dynoing on Friday and I used my tried and true 100 mile at a time heat cycle break in. That means I drove the car in 100 mile stints with each stint seeing a few trip to redline(no trip to redline in the first stint. Then the car was parked and allowed to completely cool and this was reapeated 10 times.

I have built racing kart motors for a few years and this type of a procedure always worked best in race kart motors and my track driven street cars. My street cars have consistantly been faster than their "manufacturer's suggestion break in brothers."

 

BREAK-IN SCHEDULE
During the first 1,200 miles (2,000 km), follow
these recommendations to obtain maximum engine
performance and ensure the future reliability
and economy of your new vehicle. Failure to
follow these recommendations may result in
shortened engine life and reduced engine performance.
I Avoid driving for long periods at constant
speed, either fast or slow. Do not run the
engine over 4,000 rpm.
I Do not accelerate at full throttle in any gear.
I Avoid quick starts.
I Avoid hard braking as much as possible.
I Do not tow a trailer for the first 500 miles
(800 km).

 

Follow this procedure to have a slow *** car.

 

Sounds to me like Raceboy knows his sh*t, but it's kinda hard to ignore the Official Nissan Stance. So........I'm going to compromise, personally. Sorta. I'm going to keep it under 4000 for the first 500 miles, then bring it up to 5000 for the next 250, and then 6000 for the next 250. 6600 (which I believe is the actual redline?) OCCASIONALLY for the next 200. After that, I'll be driving like I stole it, to steal someone's signature... (Apologies in advance!)

 

When I purchaed my new 260Z back in 1974, I asked the dealer the same questions.. He said, get in the car and drive it the way you want.. Don't be afraid.. I took it up to 90 MPH on the way home.. After 168,000 miles, The car ran perfectly.. I had the original clutch, it never burned a drop of oil and the compression was the same in all cylinders.. I realize it was a very simple 2.6 litre single overhead cam engine.. The 3.5 litre is a much more complex engine with so many computer controlled functions.. I think I'll take it a bit easier but if it goes over 4K RPM, I really don't think it's gonna hurt the engine..

Picking up mu 6MT Touring model in 5 hours..

Steve (k2we) Dobbs Ferry, NY

 

Somehow I don't even think experts would agree which break-in method is "best."

 

I broke my car in using raceboys advice. I slowly redlined 4 times. once in each of gears first through fourth, and cooling the engine after each time. I have 1600 miles on it now and it runs sweet. No lag, just raw power whenever I want it.

 

The fact that there is not standard procedure leads me to belive that breaking in probably isn't that important. If it made such a big deal in how the car performed or how long it lasted, somebody would have figured out the one absolute best way. Engines are different, but inherently, they're mechanically the same, whether they're made by Nissan, BMW, Ford, anybody.

I personally am trying to follow the Nissan suggestions, though keeping it below 4000 is tough. Also, what exactly is considered a "fast start?"

 

raceboy-

The interesting thing about your assertion that your method being correct for the Z because it worked on your racing kart motors is that last time I checked shifterkarts use two cycle motors. They also don’t use continuously variable valve timing.

You have mentioned that you believe your method to be the only way to produce high power, high performance motors. Yet, I have seen vehicles that were meticulously broken in following the manufacturers recommendations put down hp/tq numbers in the upper range for the specific models. So, I would say that your proclamation of your method as the only proper way to break-in ANY motor is a little premature. From your success with other motors I would say that your procedure may not be the worst way to break in a motor, but it definitely not the only way to get an engine to perform at its best. I do think the heat cycling aspect of your procedure may be a valid part of an engine break in, I would just do it within the limitation of the 4000rpm restriction. Obviously, the temperature will not be _quite_ as extreme. Actually that would be an interesting piece of data; the temperature differential between revving the motor to a max of 4000rpm vs. 6000rpm.

Here’s a link from a gentleman with whom you are very familiar, and I would imagine you respect his knowledge of engines, Stephen Gunter.

http://www.geocities.com/MotorCity/7177/trdbreakin.html

Obviously, this is not for a new car, but I do find the part about not revving over 4000rpm before 500 miles interesting. I guess you could say that if you look for something to back up your belief for the proper way to break in a motor you will find something to back up any method.

I really wish we could get an explanation from Nissan as to why they recommend this specific procedure.

JD

 

I searched the net for the words 'break in engine' and google gave me a few hundered hits.

After reading quite a few, I have determined that the FIRST 500 miles is the most important and most of the experts seem to agree that this is for the rings to seat correctly!

I have owned 20+ cars and broke all of them in about the same. No high loads on the engine for 500 miles, easy shifting and normal braking (not excessive nor overly gentle).

After that I slowly increase everything (rpm, loading, speeds, g-forces etc.) and about a 1000 miles, I let her rip.

I intend to break in my Z this way too.