I have read several threads here about proper break-in techniques for newly rebuilt motors. I am nearing completion on the rebuild and wanted to make sure I have my ducks in a row.

It's basically a zz4 engine build. I am using GM's roller lifters, Comp Cams Pro Magnum roller rockers 1.52 ratio, ZZ4 aluminum heads, and flat top hypereutectic pistons.

I have read where some say to use straight 30 weight oil during the break-in but you don't have to if you are using a roller cam.

Prime the engine first although some say not to worry about it. I would rather prime it first even though I am using a little assembly lube during the build process.

Seating the rings. Two sides to the story here too. Some say for the first 500 miles to vary your speed so the rings seat better. Others say to not worry about it and just take it easy for the first 500 miles.

Change the oil after the first 500 miles. Use a full synthetic 10w-30 at this point. Unless you want to use it from the get go and not use straight 30w oil.

Obviously, need to make final adjustments and such after its in the car and running.

I think that what I am going to do is use 10w-30 from the start since I am using a roller cam. I plan to vary my speed to help seat the rings better and change the oil after 500. Is there anything I am leaving out? What else would anyone recommend?

I have one other question. I am to the point where I am about ready to install the hydraulic roller lifters made by GM. Should I soak these in oil so that they are filled with oil before assembly? What do you all recommend?

Thanks in advance for any thoughts, suggestions, and answers. I'm open to hear any and all advice.

Thanks,

Pat Rogers

 

You should go more then 500 miles before going switching synthetic. You want your whole engine to "break in" or "wear in" (like cylinders, chains, gears...) first. Could be a myth...but stuff like factory Vette engines get synthetic when they are born, but during machine they do something different to accomodate the synthetic.

 

I have heard to start driving the car like you are always going to be driving it after the first 500 miles.

Whatever engine oil you are going to use you should start using it initially!

I recommend retightening head bolts after 500 miles also! My dad and I did built an engine and he told me to go ahead and retighten them, yeah they were all way off (that is of course if you are using new head bolts)

 

Roller cam, take it out and do some nice gradual pulls with it to seat the rings. Don't let it just sit there and idle, you run the risk of screwing up the cross-hatch on the cylinder walls. You want to get some pressure in there and make them rings expand against the cylinder walls.

I normally start it, vary RPM, get it up to operating temp, check timing, leaks, etc. etc., overall inspection; drain the oil (get all that assy and moly lube and whatever else might be in the oil out of there), fill it back up, take it out, and "seat the rings".

 

Dave88 has the method i'd use.

You want cylinder pressure to seat the rings. Moderate throttle acceleration runs, engine braking, etc. Get it up to temp and check timing and fuel and whatnot. Don't idle it, don't baby it.
As long as you're ok with your fueling and timing, ratbag it. Run it pretty hard, that'll seat your rings very nicely. Then you can dump out your cheap 10W30 and put in some nice 10W30 synthetic after 500 miles or so.

 

Thanks everyone for all the advice! I really appreciate it a lot! It sounds like I am pretty close to having the right combination for the break-in.

What should I do about the roller lifters? Do I need to soak them in oil and "prime" them before I install them?

Thanks again,

Pat

 

No, the roller lifters do not require pre-oiling internally no lifters do. Flat tappet setups require lube on the cam lobes roller cams do not.

 

If the lifters are new you should soak them in mineral spirits over night
to get all the anti rust stuff that is put in the bearings at Assembly out.
Then soak over night in oil.

 

Hey all, Digging up an older post here but its along the same lines but I have a few more questions.

We've got a crate ZZ4 just about to be started up within the next few days (i hope) which seems its been ran at the factory before being shipped.

We have changed the Distributor to a different one as supplied (Changed to a MSD one) which says that it must be lubed up, ran on mineral oil and brought upto temp and working conditions for a run in period. It doesnt say how long this is. Can I assume its similar as cam shafts, 20mins at 2000 rpm? Is it safe to do this as soon as the engine starts up? Well I mean within the first few mins of it starting up. Will the cam in the new engine have been brought upto temp at the factory?

Cheers

 

check this out
http://www.mototuneusa.com/break_in_secrets.htm
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You meant take out the cam ???

 

No, I don't think he meant take out the cam... He meant seat the rings. ??

That mototune site has very good info on break in.

 

In the gm tech flyer we get at work gm says you can break in a motor with synthetic motor oil.

 

mobil1 or castrol gtx



when i started up the LG4 in the 85 elky after totally having it rebuilt and assembling it myself with brand new .030 over pistons and 350 replacement cam i didnt use EOs from the dealer because they had none anymore



it is doing great


no problem at all runs so smooth and perfect


keep the rpm up pretty good for as long as you can, change the rpm a little a few times to change the oil splash on the cam and such


breaking in the flat tappet cams is the most risky part of it all

roller cam engines are the simple ones to break in really no worry at all with them

flat tappet ones are a gamble

sometimes they can wipe but usually they wont wipe

good luck

 

Just take it out and beat on it.