Yeah, so my rebuilt LT-1 is almost ready for prime-time. A few more bolts then it will be time to add fluids and start her up.

So there's the rub. What's the proper procedure for starting and conditioning a new engine? I've heard everything from "vary the RPM but don't do anything crazy for 500 miles" to "take it to an autocross to break it in".

 

I always broke them in hard but not like I hated them. It seats the rings better IMO.

 

because you have an LT1, which I'm assuming you kept the optispark, I'd pull the coil wire and turn the engine over a good 30 seconds. Make sure the battery is well charged. I also removed the valve covers and oiled the hell out of the rockers. If the camshaft was lubed properly, keep the car at 2000 rpms for another 20-30 minutes. Take it easy the first couple 1000 miles or so.

 

Check this out
http://www.mototuneusa.com/break_in_secrets.htm

 

First thing I'd do is use some 'regular' oil in it for the iniotial startup.
Yeah, I KNOW I'm going to hear all kinds of 'GUFF" over that.
You guys do it your way, I'll do it mine, thank you very much.

The most critical part of starting up new engines with new camshaft and lifters was to not let the engine idle or run below 1500 RPM for the first 15~30 minutes.
You won't have to worry about that because you have a roller cam/lifters on yout LT1 engine.

Pour oil over the rockers if you have the stock rocker arms/*****.
If you assembled those with assembly lube don't worry about oiling them down before start.

Have a buddy there with you if you can to help look for leaks, anything going wrong, ect.
Have all the fluids topped off and ready to go when you bring her to life.

About the only thing you'll be breaking in is the ring seal.
If you used 'Moly' faced rings they will seat v-e-r-y quickly in about the first 30 minutes of running (or sooner).
Molybdenum is very soft material. You can scratch it with your fingernail.
Cast iron rings take a bit longer.

The purpose of using regular oil is to allow the rings to have some friction so they will 'normalize' to the cylinders.
The rings have to scrub off the little peaks and valleys that were created when the cylinders were honed.
Until that happens they cannot seal as effectively.
THe oil control rings are very thin and will seat quickly.
It's not logical to add friction modifiers or synthetic oil to make this take longer to accomplish.

Plan on changing the oil and filter after it's been run a couple of hours.
Synthetic oil will be ok at this time.
After then run it however to want.

Good luck with it!!

Edit: If you have already filled the crakncase with systhetic oil.... drain it out into a clean bucket or something.
You can use it immediately after the 'breakin'.
DO NOT FORGET to fill the OIL FILTER with oil before starting. Fill it, let it soak then fill it, let it soak until it's totally FULL before you install it.
The reason for this is the filter has to get full before the oil system will pressurize.
The engine essentially runs without oil pressure for those seconds before the filter is full.
This is a good reason to do the same when changing the oil.

 

Thanks for all the replies, we started the car up and ran it for several minutes at a time, cycled it one more time and it took an idle.

Now I'm having clutch problems, but it's not a big deal because replacing the entire clutch hydraulic system is << than what I've already done (and I won't replace the entire system unless it's necessary).