Hey guys!
Just had my motor rebuilt in my 92 Z, relatively stock rebuild with intake ported a bit.
Just wondering, the shop I got it done at said to drive it VERY soft for about 800 km's (around 500 miles) then bring it in to get oil changed, get them check it over, the I have to baby it AGAIN for around 3 000 km's (2 000 miles) then change over to synthetic, THEN I can stomp on it.
I don't know if I can do this! LOL. Is it really this long to breakin? it's a rollercam etc. it's 350 TPI. 700R4 with 2400rpm stall torque converter **** kit etc. car has a couple mods exhaust, intake, intake-ported, free mods.

what do you guys think? could I do 300 miles, change oil, then baby it for another 1000 miles and change it again? can I shorten this at all?!

thanks
garett

 

Well since you have a roller cam, then it must be the rings that they are concerned about.

Did they use moly piston rings? Those take a little longer to seat onto the cylinder walls.

Or even if they used cast rings, if they didn't use a torque plate when they honed out the cylinders, then it'll take a little longer for them to seat.

Sounds like they may just be playing it safe to. If they warranty their work, then they are just covering their asses.

AJ

 

The rings should "MATE/SEAT" fairly quick....if they don't somethings wrong. I know your motor is in your car but you can extrapolate.
Our genral break-in proceedure goes like this: flat tappet motors remove inner spring or use lower rate, rollerized no changes. Add warmed oil/water (110-120) to motor, prime oil pump. Advance timing (a little, keeps ex temps down). Run for 20 minutes (steady, no vaccum pumps) just above intake standoff and below cam's pwr range.
Install springs set lash (hot). let set over night (rings will loose tension first heat cycle). Next day, step 2. Connect vaccum pump (crankcase). Run set timing. 8-10 quick pulls 1/2 way up pwr curve. Full pulls until TQ/HP stops increasing...rings are mated...put syn oil in, put motor in car or trailer (back up).
We've been doing this for fifteen years in our late model and street motors and have no problems due to break-in.

 

Hit the freeway and can it, that should break it in! Or check this link, it explains step by step how to break in your engine:
http://www.gmgoodwrench.com/crate_eng/startup.shtml

 

I just read that link and that sounds similar to what they told you Garett92Z, doesn't it? Which would make sense since GM only uses cast rings in a majority of their GoodWrench crate motors. Cast rings seat faster to cylinder wall imperfections. So what they told you sounds right.

But if they used moly rings, they take a lot longer to wear into any 'out-of-round' cylinder walls because they have harder metal in them. It usually takes about 5000 miles for a moly ring to wear into a wall that was not honed with a torque plate installed. A lot less time if one was used. And usually the crosshatch is different for moly rings.

Does that mean the the rings will fly apart? NO. But the actual seal that they provide will not be as effective until they seat properly. That's all.

AJ

 

thanks for all the help/info guys
Looks like i'm going to have to get my girlfriend to drive the car and I'll have to ride passenger... because I KNOW I couldn't drive it grandma for that long, lol.

the girlfriend and I are going on a bit of a road trip next weekend so that'll put some good km's on it... she'll drive, then I'll change oil when I get home.

Looks like I'm going to have to wait a few weeks til I go rice killing

Garett

 

Look at drag cars, they break in the cam, maybe to a half throttle run, and then get on it. The engine will last seasons.

After the cam is broke it, break it in like your gonna drive it. But take it easy the first 100 miles.


Heated engine oil, that is a new one.....