You hurt your what?

 

I am going to breaking in my new motor soon so this is of intrest to me. I am going to do quite a bit of it on the dyno I think. However, generally I have seen two methods:

1) Conservative driving for 1000miles
2) Varrying semi-aggressive driving for 100-300 miles.

From what I have read, the first one will give you a longer lasting motor but may not seat the rings in as good as the second. The second one may give you a negligible power increase over the first one due to better seating of the rings at the expense of a shorter life. Of course this is all therotical. I plan on varrying the throttle and rpm's a great deal on the dyno.

 

Another question, What weigh oil you guys recommend I use (im in miami, so cold weather is no issue), I had seen a thread with built guys using like 15w50 or real thick oils, im wondering why, perhaps their builds have loose clearances? loose bearings, pistons perhaps.

I basically have ACL standard size bearings, and not 100% sure what clearance the block was bored too for the Wiseco's I have. right now im using 10w40, is that fine? what u guys think?

 

did you do anything to the tranny to handle the new power coming up? 97 Auto right?

 

For the tranny, what keeps it alive is a big cooler I have for it, fully synthetic ATF (mobil 1), the rest is electrical. I have a WOT switch that activates full line pressure for instant non slipping shifts (basically like a VB upgrade). This is what has proven to be the best way to keep the auto on the Maxima healthy. The fastest maxima right now (runs high 10's) has exactly the same thing on his auto.

 

who Jime? not too sure what his mods are.. you might be running a whole lot more power than Jime though.. depending on what you do with this built motor.. but the maxima VQ's and trans on the 4th gen were always stronger than the 350z DE motors.. so a VB Upgrade and Cooler might be enough for you

 

Well his spraying a good amount through his vq35, I believe his making about ~500wtq range with a 150-200 shot. as for tranny he has same things i do (I basically go by what he does)

 

oh ok

 

From my experience of building up high output engines both japanese and american v8's, the technique I and a couple other engine builder friends of mine use is this:

1.) Use regular oil, make sure the coolant is topped off, disable the cooling fans.
2.) Start the engine for the first time and let it high idle so that the temperature gets very close to overheating then turn off the engine.
3.) Let the motor cool down just a bit and re-enable the cooling fans during the cool down.
4.) Start the engine again, drive it out of your garage and run the car like a race engine to redline full throttle and allow the engine to decelerate.
5.) Repeat this full throttle / deceleration for about 20 minutes and the rings will be sealed extremely well.

The slow break in specified in manuals doesn't work... it causes oil blowby for the rest of the life of the engine... guaranteed. The easier you were on the breakin, the more oil you burn later on (many of you that burn a quart of oil in between oil changes is because most of you did the factory recommended break in...) Also, for break in you need to very low 2-3psi boost. If you're boosting over 7 it's way too much for initial break in of that 20 minutes. There is a difference between breaking in and just out right scouring the piston walls from too much boosting. We tried breaking in at 28psi on a 2jz fresh built engine.... and we won't be doing that ever again.

Truly this site does explain it best:

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

 

Thanx for your advices..

So far I have 1,300 miles on the motor right now (in my opinion i think this **** is broken in already), it has been at 5psi, the first 500ish miles i drove it normal(not baby, but not beat on it either), then as I got closer to 1k i would do WOT runs on highway and let decelerate, and repeat. at 1k miles I changed oil again, and then started abusing it a little more, been doing alot of higher gear WOT (still at 5psi).

 

I have always lived by motomans theory of break in on all of my vehicles, from my bikes to my cars to my trucks. since day one when i bought my z brand new i ran it very hard!!! maybe this is why my rev-up engine never burnt any oil unlike many of the others out there....... i installed the vortech after only 500 miles on the odometer as well.....