Technical What oil to use after breaking in a new engine

I have the correct break-in oil(not synthetic) but am concerned about what oil to use after break-in.. They say NOT to use synthetic(and I don't want to) for 3,000 miles, but the Brad-Penn 10W-30 oil I purchased is 10% synthetic.. Will it be OK to use after the initial(30 min.) break-in and as my oil of choice?? I use it in my other cars and like it.. The engine in question is a 350/ 290 HP from Jeg's....

 

Brad Penn would be an excellent choice.

 

Im running Brad Penn 10 40 after my Break in .

 

I broke mine in with Royal Purple's break-in oil, and they say to switch to their synthetic after that, so I did. I guess it could also depend on what time of camshaft you're running, mine is a roller but if you have a flat tappet then the rules may be different.

 

GM Performance says for that motor;
After installing the engine, ensure the crankcase has been filled with 10w30 motor oil (non-synthetic) to the recommended oil fill level on the dipstick.
After approx 1 hour, Change the oil and filter. Replace with 10w30 motor oil (non synthetic) and a PF454 or PF1218 AC Delco oil filter. Inspect the oil and the oil filter for any foreign particles to ensure that the engine is functioning properly.
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.
Change the oil and filter. Again, inspect the oil and oil filter for any foreign particles to ensure that the engine is functioning properly.
Do not use synthetic oil for break-in. It would be suitable to use synthetic 10w30 motor oil after the second recommended oil change and mileage accumulation (500 miles). In colder regions, a lower viscosity oil may be required for better flow characteristics.

Interesting that they say to NOT use the vacuum advance on the supplied HEI Distributor!

 

I don't want to sound like a smartass but why not run Synthetic from the start. All new cars have it in from the factory ,they don't use or reccomend " break in oil"

 

Castro gtx 10w-30

 

Follow GM's directions as posted above for the warranty. If it goes bad, they cannot come back on you for using the wrong oil. After two oil changes, run what ever brand you like. If it has a higher lift cam or heavy valve springs, run a little additive with each oil change.

As for new cars and no break-in, they all run some sort of roller cam, which doesn't require break-in of the cam and lifter surfaces.

Use a good filter, Wix or Napa Gold, Mobil One, Delco and I am sure some others, are all very good filters. Stay away from the cheap store brands unless you are sure who made them.

 

I'm sorry, I should have said it is a flat tappet engine not a roller cam engine.. They don't recommend synthetic oil until the engine has about 3,000 miles on it.. I also don't want to run a full synthetic oil.. But thanks for the comments so far...

 

IMO, yes it will be fine. I'm not sure why they say not to run synthetic anyway, that would be a good conversation to have. If the Brad Penn oil you want to use has 10% synthetic content that is not going to inhibit the complete break in of the engine, go with it.

I do wonder though where you got the 10% figure from, did they tell you that?

 

Thanks for your comment Blues4U.. I thought it would be OK too.. Got the 10% figure from a website.. See post below...

 

Hey Blues4U, The article was "Frequently asked questions about motor oil" at inengineering.com/resources/2014/02.. The section about partially synthetic oils stated that Brad Penn's was 10% synthetic....

 

My New Ford came with a Synth blend 5W20 - Not a full synthetic.

 

Thinking out loud here...
GM built the engine and gave instructions for its use and care. They've got everything to gain by having the engine broken in correctly so they get very specific about what type of oil not to use. You've got everything to lose (warranty wise) by varying from the recipe.
According to what Hotroddon posted, on the third oil change (500 miles completed) you can use anything you like.

 

Sort of, they still call out the weight though .....

 

If you can find Scheaffers oil in your area, they make an outstanding semi-synthetic oil. I used it with a flat tappet cam motor on alcohol. 250 passes on the motor and reused the bearings after inspection.

 

I have a new flat tappet engine I have yet to fire.. I have Brad Penn break in oil(straight weight non synthetic) for initial start up and 30 min. run in.. When I drain that oil out, I want to put in Brad Penn 10W30 oil that happens to be partially synthetic(only 10%).. Will I be OK using it is what I want to know...

 

We only use Brad Penn and Wix filters in all flat tappet engines we build and service.

 

Also keep your receipts for the oil and filters. Document the dates and mileage of your changes. (just in case)

 

Linky no worky....

 

Being in the lubrication business, we deal with OEM's that are pretty clueless about oils and grease all the time. Just cause a guy is a mechanical engineer doesn't mean he's fully up to speed on lubricants, and a lot of times it does come down to 1 guy making the decisions, cause everybody else is clueless as well. I'm not speaking directly about this situation, because I don't know the particulars, I'm just saying, the OEM's don't always know WTF is going on with oils.

 

Better yet, send a sample out for used oil analysis, and keep a history of every sample. If something doesn't look right, send a copy of the sample to the builder/seller and ask them what they're going to do about it.

 

I used to rebuild diesel engines for a living, engines that cost $30k and up. We never used break in oil, we just used the same oil the engine was going to be run on, usually a 15W-40 diesel engine oil, sometimes straight grade 30 or 40 if the owner was old school. The break in procedure was to get the engine fired up, usually re-installed back in the chassis (sending it out to be run on a dyno was very rare), check for leaks or anything out of place, and if all looks well, we'd start loading it down, gradually increasing the load and bringing it up to temperature, after maybe 5 - 10 minutes we'd have it up to full load, turbo chargers glowing, checking & recording high idle speed, low idle speed, convertor stall speed, Full stall speed, intake manifold pressure, oil pressure and fuel pressure. If everything was copacetic we'd shut it down, retorque the head(s), rerun the overhead, recheck for leaks and fix any that we found, and then put everything back together and release it to go back to work, no babying. When it was back to work they expected full load applied, right from the start, there was no taking it easy for any period of time. Let it happen Capn'. We did tell them to change the oil after 100 hours the first time, then go to full drain intervals after that. I always wondered why we are supposed to baby car motors, when it was never a practice in the heavy equipment business.

 

Hey Blues4U, try typing in "Frequently asked questions about motor oil"...

 

I did my flat tappet 355 with Valvoline VR1 10W-30 oil, what the builder recommended. You want that immediate flow that a multi-viscosity oil provides. I used a Comp Cams break in additive with the VR1. My next oil change was VR1 again, the following one was Brad Penn 10W-40 Synthetic blend.