My 96 z is in the shop right now, thanks to the man who sold it to me not telling me that it was going to die. He blew the head gasket but kept driving it and now its finally gone. So they are rebuilding the engine as well as a new clutch and radiator. I have heard that I should drive the car for 1000 miles in city or somewhat traffic areas before i can take it over 3k rpms. Is this true, or how long should i take to break it in before i can drive it like a Z should be driven..this is my first posts, thanks in advance
Billy

 

let the cam break in at 2000rpms for 20 min or so

then let all hell break lose for the next 500 miles-
NO CONSTANT RPMS( HIGHWAY)

moly rings like to seat in heat/pressure

 

When your doing a motor with new internals or .040/.030 over bore, use only convertional mineral oil.

They say to do drive the car no more than 30 minutes at a time, let it cool, no more than 50% throttle, but do different RPM ranges. Do this for 500 miles.

Do a oil change + filter, mineral oil. Then repeat, you can go up to 70%, vary the rpms and let to coolat 30-40 min intervals.

At the 2nd 500 miles (1000 total), change the oil, put what ever you want (mineral, syn blend, or full syn) and Beat the ***** off the car.


IF its just a head gasket, it all depends but i know about the complete engine rebuild.

I mean with gasket, jsut that, just do the same but minus the oil changes. Maybe one, vs 2.

 

I was always told when motors are fresh to take it easy and break them in slow. I know a guy that took 2 indentical setups. One he broke in slow , while he beat the crap out of the other one. The one he beat the crap out of made 30 more hp than the one the was broken in slowly. I would recommend using mineral oil for the first 3 oil changes.

 

Well it's been about 65 days but im finally getting my Z back today. Every single thing they mechanic ordered came in late or it was the wrong kind and its been prob after problem. But in about 45 mins im going to get it and he said it was running really good so ill see how it works. Thats a long wait when you have to drive a 4 cylinder in place of a z28!

 

What if your engine is being built for Darg Racing only? My compression will be in the high 13s to low 14s. Dont think I will be driving the car on the street for the first 500 miles when I will be burning Racing fuel all the time. Car will be street driven but not that often.

 

You probobly would want to pull some timing and run a 93/100 octane mix and drive it around for a LITTLE while at least.


in refrance to normal motor-
the rings really like to be heat cycled

 

A couple of guys here are on the correct track. As long as the fuel and timing are reasonable, break it in hard with full throttle with high vacuum breaks in between, preferably using dyno oil. I know, some oem use synthetic on startup. I feel dyno will just give a little extra for ring seating. Ring seating is the primary concern. Cam breakin procedures are intended for flat tappet cams, no need to worry 'bout cam breakin a roller cam. You don't need to wind the sh*t out of it, to break it in hard. This means full throttle, but don't redline the engine. With moly rings and decent wall prep, if the rings aren't seated by 500 miles, they may not ever be seated as well as possible. The 'healthiest' engines are run hard and seated quickly. When was the last time a nascar engine was driven 'easy' on the street B4 goin' racin'?

 

Good point Arnie.

 

On the flip side, a NASCAR engine's rings only have to last to the end of the race.

 

True, but do you think they would do anything to jeopardize power (ring seal), or engine durability/longevity for that matter? Remember, they are making power in an rpm range that is on the ragged edge of durability the way it is. They certainly wouldn't do anything to compromise that fine line of durability that they already walk.

 

Excellent point arnie.

I usually break mine in like so..... 200 rpm per second step increments on up to, and slightly beyond peak power, on the dyno.
Run the same engine after adequate cool down and you'll be up on power.

-Mindgame