MX-3.com

Ok guys the million dollar question.

the ZE is built finally ( Thanks Mike!!! )



Now Ive heard there are 2 ways of breaking in an engine.

Hard break in for the 1st 20 miles
http://www.mototuneusa.com/break_in_secrets.htm

Or slow breaking in as described in most factory manuals.

Also Ive read this..
"Generally, you shouldn't push a new engine above 4000-4500 rpm. Also try to avoid pushing the gas all the way down, and generally be gentle with your engine. This should be done up to the first oil change, usually around 4-5K km.
This "breaking" procedure helps your engine to smoothen the surfaces and reduce friction.

I've also read that new cars shouldn't be driven at constant speeds for the first 500 miles or so meaning avoiding hgihways if possible or adjusting your speed consistently on highways.
I've never heard of that one, it's probably false.
"


What are your experiences with break in periods and what were your outcomes?

I don't know which is better per se, but after I rebuilt my KLDE, I did the idle for 10 minutes thing, drain oil and new filter first. Then, I TRIED to be somewhat gentle with it, but after 50 miles of driving like a woman, I just couldn't resist to start ripping into it to redline.

standard rebuild Barry or "aftermarket" build ?

Millenia Block and heads.
KLZE pistons, stock rods.
Stock valves.
Everything else is basically new.

So ya a standard rebuild.

I bought a degree wheel and a dial indicator w/ magnetic base this past week. Im gonna find out if KF01 cams are actually more agressive than the KL31 cams. I havent pulled the motor yet, but will test the lift/duration when I pull the motor.

standard rebuild doesnt require much, you can follow standard engine break in guidelines. If it were custom build Id break it in for 20 mins then drive it way youd drive it around, ie race engine Id take it on streets and race it. Change oil and then change oil after another 500 miles. id use rotella diesel oil (assuming engine was hi-po) then after its done breaking in Id use synthetic oil for the rest of oil changes

When I was up at Interprep years back I asked Alistair how he broke in all his race KL engines. He told me with the gas pedal. I'm with the guy on the Mototune site, I'd give her hell the first time out after she's fully warmed up. Plus if you blow the engine you can just blame it on me!

I got a engine rebuilt in a truck before and they told me to run the hell out of it for a few miles to break it in then drive it normally. Cause if it is going to break on you mine as well find out if it is going to break on you now and not a week later.

I seem to be seriously outnumbered here, but I've always heard to avoid constant speeds, don't go over 5k rpm, don't rip into it, and do that for the first 3k miles. The reason for all that is that the block, heads, oil pan and valve covers are straight. The heat will warp them and you want them to warp slowly at lower temps so that the bolts can do thier job and let them warp at the same rate and in the same shape. This will make sure that you get good seals, less leaks and internally less friction. I've only ever had 2 rebuilt motors and neither in the MX, but I seemed to have less than average trouble with both of them. Neither leaked. One got about 50k after the rebuild and was a 2.3L 6cyl Chevy motor which leaked like a sive before. The other was sold shortly after.

I broke in the SRT-4 very hard and it definitely payed off, I have one of the fastest stock SRT-4's in Calgary < I eat stage 1's> Drive it like you stole it!

I also heard both ways.
As far as I'M concerned...After the rebuilt I immediatly gave it 5psi of boost..I guess that's equivalent to a beating. engine runs fine now

Use regular motor oil during the first 1,000 miles, DO NOT use synthetic oil and this I saw it in NOPI TV when the techs rebuilt a turbocharged 1,000 HP Supra.

thats how I did mine, the cheapest regular motor oil in the first 1,000 miles.

Change the filter and oil after the 500 miles break-in.

when i did my break in i changed my oil out every 500 with cheap oil and when i got to 1500 i put in Synthetic( didnt really have to change the oil that many times but i wanted to make sure i flushed everything bad that could have been in there from the motor sitting out). i also ran it in Limp mode for the 1st 500 miles, then pulled it out of limp mode and everything ran great!