Break in oil......how long??
 

327/300 with OEM style cam. Did the 20 minute run at 2000 rpm etc. and several ten minute idle runs after that. Using Brad Penn 1500 zinc content break in oil. The builder I used said to run the car 75 miles at various speeds up to 60mph and then change the oil. A well known local builder of race engines that built an engine for a friend at the same time I was having mine done said he changes the oil after the first 20 minute run. Any thoughts on these two options??

If you wanted a perfectly clean engine, devoid of all contaminants, you would change it every 10 minutes................

Changing after the first 20 minutes is overkill. Even changing after 75 miles borders on overkill.

Changing after the first 500 miles would be ideal (to me).

That is assuming I built it, and know that I didn't leave crap, lint, metal chips, etc. inside.

Note that if you are using an engine oil supplement such as GM EOS (or most cam lube) that has Moly Disulphide, it can lead to contaminants that (when they migrate to the combustion chamber) cause knock. Not saying you should not use it, just beware and change oil as soon as any knock appears (assuming timing and fuel curves are correct) to eliminate that possible reason. And it will take time to get rid of those deposits out of the combustion chamber. In other words, that can be a good reason for changing to oil earlier.

Everybody will have an opinion on this, so it will be interesting to see the answers you get!

Plasticman

I followed comp cams reccomendations. 2000 rpm @ 20 mins. Varying the speed slightly during that time.The cam needs this because it doesn't get suffcient oil at idle to break in. The splashing oil at 2k rpm keeps the cam wet during break in.
Then changed the oil and filter which also had comp cams break in additive. I will run the additive through one more oil change. Then I will use an oil with proper zddp levels. I refrain from naming the brand. To keep the chemist nerds "you know who you are" :rofl: from chiming in with their opinion..
I also use a magnetic drain plug. I was amazed how many graphite fine shavings it collected from the break in. I will use magentic drain plugs from now on.
I will go easy the first 2k miles. Making sure I run the motor through the rev range on a regular basis. Vary speed, load etc..
My 2 cents worth. I am sure the obvious characters will tell me how wrong I am. It's worked on my last 3 motors. One with over 100k miles. So I guess I was doing something right. :cheers:

I change oil and filter after cam break in, then change again after 300 miles, then one regular interval, then onto synthetic.

:iagree: Come to think of it. I did do a second change shortly after the break in change.

you running a flat-tappet cam or roller?? And what weight synthetic ?

Flat tappet

Comp cams recommended a cam lube when I built my motor for my old 32 Ford 3 window. Then per above, run the motor 20 minutes and change the oil to get rid of the cam lube. Then vary speeds and RPM the next 300 to 500 miles which may be overkill. Change again and you are done. With my 65 corvette, it has a 383 stroker with roller cam and lifters and no break-in needed. :thumbs:

Change the filter immediately after cam run-in, AND DISSECT IT. Change the oil and filter after the first 200 miles.

"Using Brad Penn 1500 zinc content break in oil........."
All of Brad Penn Grade 1 racing "green oil" has 1500 ppm ZDDP.
The break in oil has MORE than 1500 ppm.........proprietary formula and you will NOT find the ZDDP content published anywhere!!
I called, and wrote to The American Refining Group, makers of Brad Penn motor oil and THEY WOULD NOT TELL ME THE ACTUAL ZDDP CONTENT OF THEIR BREAK IN OIL.

Gm recommends for their crate motors that you run the break-in oil for 500 miles before changing it.

Actually, (at least for the ZZ454) they recommend TWO changes before 500 miles. From the ZZ454 paperwork...

Start-up and Break-in Procedures

4. Start the engine and adjust the initial timing. If using the HEI distributor P/N 93440806, set the ignition timing to 4º before top dead center (BTDC) at 650 rpm with the vacuum advance line to the distributor disconnected and plugged. This setting will produce 26º of total advance at wide-open throttle (WOT) when using the HEI
distributor P/N 93440806. The HEI vacuum advance canister should remain disconnected. This engine is designed to operate using only the internal centrifugal advance to achieve the correct timing curve. Rotate
the distributor counterclockwise to advance the timing. Rotate the distributor clockwise to retard the timing.

5. When possible, you should always allow the engine to warm up prior to driving. It is a good practice to allow the oil sump and water temperature to reach 180°F before towing heavy loads or performing
hard acceleration runs.

6. Once the engine is warm, Double check the total advance timing is 26° at 4000 RPM if using the HEI distributor P/N 93440806.

7. The engine should be driven at varying loads and conditions for the first 30 miles or one hour without wide open throttle (WOT) or sustained high RPM accelerations.

8. Run five or six medium throttle (50%) accelerations to about 4000 RPM and back to idle (0% throttle) in gear.

9. Run two or three hard throttle (WOT 100%) accelerations to about 4000 RPM and back to idle (0% throttle) in gear.

10. Change the oil and filter. Replace with 5W30 motor oil (not synthetic) and a PF1218 AC Delco oil filter. Inspect the oil and the oil filter for any foreign particles to ensure that the engine is functioning
properly.

11. Drive the next 500 miles under normal conditions or 12 to 15 engine hours. Do not run the engine at its maximum rated engine speed. Also, do not expose the engine to extended periods of high load.

12. Change the oil and filter. Again, inspect the oil and oil filter for any foreign particles to ensure that the engine is functioning properly.

13. Do not use synthetic oil for break-in. It would be suitable to use synthetic motor oil after the second recommended oil change and mileage accumulation. In colder regions, a lower viscosity oil may be
required for better flow characteristics.

I dump it after initial start up and run in...especially after a flat tappet cam break in. The filter will be full of moly lube and will have all the lint and fuzz that will amaze you trapped too. I like to get it out of there.

Then I go to whatever oil I'm going to run in it...usually going to a dyno if it's a completely new build. So the break in is done on the dyno and it's hammered pretty hard! With good machining techniques and today's parts...it's pretty much broken in in the first few minutes. You want to put some load on it early in its life to get rings truly seated.

JIM

Thank you for the info guys. I really appreciate the time spent ...and detail given to help me out. Since I really can't drive the car yet due to salty roads, slop, etc. would you suggest I start and run to operating temp every few days or just let it sit a few months until I can actually take it out and do the varying speed thing. Maybe this is another thread?? :thumbs: Dave

I would not idle the new engine at all wait for nice day and get a load on it, you could fogg it if worried with a marine agent