Over the next week I hope to get this car finally running. Its a fresh motor.

Whats the recommended way to break it in? I have heard everything from Run it hard from day 1; take it in steps of 1000rpm every 250 miles, to not above 3000 rpm for the first 2000 miles, etc etc....
Whats the opinion here? I would like to be able to run it harder as soon as possible, but I dont want to hurt the engine in any way.

Oil: I have been told to run dino oil for the first ~3000 miles, then switch to the synthetics I want to run (Mobile 1), this right? Run motor without driving for 30-45 minutes, change oil. Change oil at 500 miles and 3000 miles? More, less....?

Also, the motor has been sitting for a while (~2 years) since it was freshly redone, the shop said to prime the oil and change it before I run it, get any small dirt/grime out, other then that it would be fine. Anything else I should do? The assembly lube they used is still there, the manifold has been sitting ontop, the valve covers off, and under a motor bag.. No visible dirt, I "dusted" the heads and intake valley out and got those basically clean.

Anything else anyone can say?

Thanks in advance
Matt

 

The engine sitting for 2 years is kind of a long time. If, however, it's been sealed from the elements and you don't live in a very wet climate, it might be okay. Try it and see. Make sure you very well pre-prime the engine oil before starting it though.

You also want to make sure it's not running lean. That'll quickly wash your cylinder walls and you'll end up losing your hone. So when you start up, look for signs of black smoke. If it's really rich like that, shut her down and lean out the jets.

Oil: Definitely do not run synthetic oil on a new engine unless it's built with tolerances meant for synthetics, as is the case with the new Corvette engines. Synthetic oil is too slippery and will ruin your hone. You want to break in the engine first. 3000 miles is the minimum I'd go before switching, but I'd prefer maybe 5000 miles to be on the safe side.

When you first start it, you need to break in your cam, provided you're not overly rich. Run it at about 2500 rpm for 20 minutes, if it's a solid or hydraulic flat tappet type cam. If it's a roller cam, no cam break in is necessary.

If you want to break in the rings, I believe it's 4000 rpm for a half hour. But in my book, that does not take the place of breaking it in under a normal engine load.

So what I like to do is to drive the car normally...but NOT full throttle... for at least 1000 miles. Make sure to accelerate the engine through it's midrange, like in city traffic. If on the highway, accelerate about every 5 minutes or so.

At 500 miles, change the oil and filter to cleanse out suspended metal particles. Then change the oil at 3000 mile intervals. Every 2000 miles if turbocharged. The heat of the turbo's bearings have the effect of breaking down the oil sooner.

When you're breaking in the engine, use a light weight oil, like 10W30. You can switch to a heavier oil later, but try to avoid very heavy oils, such as 20W50.

Any other strategies out there?

 

There are some of what MoMo said I agree with, and some not. Starting from the bottom?

With bearing clearances in the range listed in oem manuals, (street engine?) I believe too many break in engines with too heavy a oil. As noted, start with 5/10W30, switching to a 5/10W40 if desired, based on operating temps.

Initial break in, as noted, is influenced by the type of lifters used. Lifter/cam break in aside, rings are the priority. Not knowing rings/hone specs, dino oil is preferred for ring break in. Not sure of the hone specs on newer engines that allow synthetic. Run this dyno oil for 500 miles. The rings are either seated, or they aren't gonna be. At this time a change to synthetic can be exercised.

BTW, if concerned about oil now in pan, change B4 initial startup.

The actual breakin process can be accomplished in less than a day. I prescribe to the cycling process. This is definately easier to accomplish on an engine dyno. The next choice, would be with a manual trans. This breakin, as stated, is intended specifically for ring seating. The actual process, (cycling) consists of the following. BTW, I am more concerned with detrimental effects of rpm, not with full throttle/full load.

Starting with 2000 rpm and ending with 6000 rpm in 500 rpm steps. Using 1st to the 1 to 1 gear. (not overdrive) Go thru the gears, shifting at 2000 rpm, letting vacuum build in between gear changes. To go thru the gears once, is 1 cycle. Do this for 10 cycles @ 2000 rpm. Then to 2500, 3000, etc. Doing this from 2000 rpm up to 6000 rpm would be 90 cycles. The rings are being mated to the walls under load, and given lube and cooling under decel/vacuum conditions. Keep an eye on coolant/oil temps and oil pressure while breaking in. This would be my prescription. :) Contradictions anyone?




[Modified by arnold, 5:23 PM 8/23/2002]

 

There are two ways to think when breaking in an engine. I would reccommend breaking it in hard and do not keep it at any of the same rpm's for an extended amount of time becuase it will wear the cam lobes incorrectly. I would still reccommend keeping it under 5,000 rpm for the first few hundread miles. I would def not run syn for at least 4-5,000 miles. If you have moly rings you will def need to break it in hard becuase if you do not the rings will never seat properly. The saying I learned on is break it in like a granny and it will perform like a granny.
Good luck

 

That sorta flys in the face of the cam (flat tappet) breakin I subscribe to. Tune correctly to enable the engine to start upon initial (short duration cranking) and hold at a steady state 2000-2500 rpm for 20 minutes. Cam is either broke in or garbage.

Does miles really have any bearing on ring seating? Do nascar engine builders put X # of miles on an engine B4 they pronounce the engine race ready? Remember, the bearing clearance is set properly at assembly. There is no wear in of bearing clearances. Wear in of bearing clearances to me means metal to metal. A definate no-no. They seat the rings and race.

I would def not run syn for at least 4-5,000 miles. If you have moly rings you will def need to break it in hard becuase if you do not the rings will never seat properly.[/QUOTE]

When breaking in the engine effectively/correctly, if the rings aren't seated by 500 miles, are they ever gonna be?