Engine break-in help
 

Alright, With in the next 2-3 weeks I should have my car running. The engine has about 40k mi on it except for the housings, they are new. The guy that ported it put an agressive street port and 2mm apex seals. I am also running a GT35R kit with all the proper mods. I am wondering what to be measures need to be taken while breaking this motor in?

Dont boost, keep RPM's around 4k. And do that for about 700- 1000 KM

Or about the same amount of Miles!

What kind of oil should I use? I heard some people say synthetic and others say mineral oil.

hope this helps: http://www.rotaryresurrection.com/3r...p_breakin.html

^^^^ Awesome link man thank you.

Thanks guys!

no prob! good luck with it!

how necessary is a break in with new rotor housings? Need some input?

Is it worth risking it to you? I know its not for me. It doesnt take that long to do a proper break in, why potentialy pop the motor or no reason...

And do you really think your the first person to have this question over all the years the forum has been around? You could find 100 threads that cover this.

What I tought. No its not work risking it. I just had some local FC guy tell me how unnecissary it was to break in an engine. You just proved my point, thanks. Anyone else?

Id say its pretty important. I stayed under 4k and no boost. I also changed my oil often 250,500,1000 (really about 850-900). I used mineral oil for break in.

Sounds like this local FC guy was feeding you bad info.

I've posted what I use for engine breakin about 75 times, if you search you'll find it :)

Thats really just a matter of opinion Rich. There are a lot of people including myself who do not do break ins. I've personally opened several engines with just dyno time only to inspect too.

Hey Elliott,

yeah, i've seen people 'break in' their motors at WOT :D

I think part of it has to do with clearancing of seals and new/used bearings. What kind of breakin do you stipulate for warrantied motors you build through your shop?

Never use synthetic when breaking in an engine

I was told 1000 miles by my rebuilder with changes in RPM and no boost. I drove one road every day after work and would go through the gears but no speed over 70 mph. Just geared down to change RPM's. It worked for me. Took me about a month to get the miles. I have never used synthetic.

Fire up motor, check for leaks, bring up to to operating temp, shut down and cool off, check fluids, start tuning and boosting.

i guess it really is just a matter of opinion. If people are having good results either way, then no one is wrong.

Yeah, it is.

Just an example for you though. I installed my 1/2 bridge last winter, had about 350-400 miles on it of just driving around, getting the idle and driveability tuned out, bolted up to the dyno and made 512 to the wheels on pump, i would have done it sooner, just had to wait on steve kan to get to st louis. Hit up the drag strip shortly after and ran some low 11s passes with probably around 600-700 miles on the motor. Ran multiple 10s passes during the summer and many more low 11s. Motor runs great, no smoke, idles great (for a 1/2 bridge), pulls like a raped ape.

The one thing that I'd be careful of.....if you have brand new rotor and stationary gear bearings, it makes sense to me to take it easy on them for a while.

I can tell ya that for motors we port/build/warranty, we absolutely require a break-in interval. Better safe than sorry :)

Whys that? Whats going to change if it is babied for the first 1-2k or if its hammered right away. If its going to fail, its either going to be right at startup or the first time its fully boosted.

I have never broken in an engine with new bearings either. The last motor I build I got 60 yards, yes 60 yards and the throttle cable stuck on me and the motor saw 8500rpms and 15psi. After that I did another 3-4 miles of WOT street tuning, and headed to the dyno. Again several more 7500rpm pulls. Tore the engine down, bearings looked as new as the day I put them in.

Pretty crazy stuff, to say the least. Good to know, but I'm sticking to my break-in schedule, at least for warrantied customer motors. Maybe on my next personal motor I'll give your method a shot :D

I'm with the "no break-in required" guys