Break in oil - what say ye?

[opus]

Getting a GM crate engine. I'm told my an engine shop to run 15w40 Delo or Rotella diesel oil for the break in period. I asked why and he said the due to this particular engine being a flat tappet type, the added zinc is needed. He also said I'd be better off running a diesel oil always, due to that fact.

Thoughts?

 

[Mackelroy]

id run the 5w40 or 10w30 diesil, no less the zinc, and quicker flowing for a new motor.

 

[Killer223]

what engine? they are broke in from the factory if it a true GM crate engine. And not someone elses crate engine that just happens to be a GM.
15/40 is kinda heavy for a brake in. i'm more the 10/30 for the first 500 miles then do what ever oil you want. i run Valvoline Premium Blue 5/40 in EVERYTHING and it's never let me down.

 

[andyd]

Do what the builder says.

 

[goodtimes]

GM built the new engine, I would use what they recommend. 5w-30, 0w-20? You want fast and good oil flow at startup in Montana I would think. Flat tappets as opposed to what kind, roller? Many cars have flat tappets, which are actually slightly domed not flat. Nothing unusual about that.

 

[opus]

Word is, they have removed zinc from all but diesel oils. Flat tappets [as opposed to roller] need zinc. I've heard this from multiple people recently.

 

[SR5]

I would use a high zinc, API approved, racing oil like valvoline VR1 for break in. Then switch to the HDEO on the first oil change.

My reason, is that I have read in a few places here, that the ZDDP in HDEO becomes active at higher temperatures than the ZDDP in a PCMO. So on your first run you want the zinc to kick in ASAP. Once broken in, I would just switch to the cheaper HDEO for regular oil changes.

We call it Running-In oil in Australia. Penrite make a nice one with 1600 ppm Zinc. They say to change it out after 500 KM.

https://www.penriteoil.com.au/products.php?id_categ=1&id_products=397

I've also heard not to let the car idle when breaking in, but go straight to higher revs (but not redline). I'm sure there are a few experts here who can offer more advice.

 

[bunnspecial]

I'd go with a dedicated break-in oil. GM(AC-Delco) used to make one, although I'm not sure. A quick google search led to a handful of specialty suppliers that still make one. The important thing in these is the ZDDP content.

The conventional advice with a new flat tappets and camshaft is to "prime" the engine by manually rotating the oil pump to build some pressure, and then doing whatever you need to do to get the engine to start as soon as possible after cranking. The engine should then be run 20-30 minutes at 2K-3K rpms with the absolute bear minimum amount of time idling. After this initial break-in, it's a good idea to drain the oil and then fill with the a more typical(but still high ZDDP) oil.

There's a lot of information out there on the internet, as well as from racing shops, about breaking in overhead valve flat tappet engines. These type of engines do need a legitimate break-in to "mate" the camshaft to the tappets. Of course, overhead valve flat tappet engines are not that common on "normal" cars anymore but there's still a big knowledge base about them out there.

 

[opus]

Oh yeah, I'm good with break ins, just was curious about the oil thing.

 

[donnyj08]

Originally Posted By: opus
Oh yeah, I'm good with break ins, just was curious about the oil thing.



Amsoil break in oil!

 

[BrocLuno]

None of the current crop of break-in oils that I'm aware of are any good. Best to use a premium street oil. The VR-1 Silver Bottle would be my preferred, but you could use a number of others... Chevron Supreme comes to mind - 10W-30 at Costco. I've had good luck breaking in GM motors on that

Many will say to put a can of GM EOS in the first batch of oil. If it's handy, maybe... But, likely it will fight with the oils built-in add pak ...

The big deal is to dump that first oil and change filter at 500 miles. Cut the filter open and see what you got?

Run a magnetic drain plug. If you have any concerns with this engine builder, run a BIG magnet on the outside of the pan bottom near the drain plug. On the first OCI, put a dowel in there with grease on it and see what you get? The magnetic drain plug will likely have shown you what's happening...

If you get shavings or bits of metal - stop and call your engine builder. Something is wrong and it needs to be on their dime... A little silver flash in the oil is normal at startup/break-in ...

Any bigger bits go through the oil pump, they will take their toll on that pump sooner than later ...

Do you have the oil filter by-pass blocked so that 100% of the oil goes through the filter at all times?

Run the biggest WIX filter (Napa Gold same) that you can fit. The additional media area reduces filter back pressure, easier to pump through

 

[Doog]

VR1 for 500 then again until 2000. Then 15w40 Delo for then next 3 OCIs then do a UOA and see what you get. If you're really anal tape a big magnet on the oil filter for the first two changes.

 

[CT8]

I gave up on blocking the oil filter housing bypass . as dirty oil is better than no oil ,though I stretched the spring. I never had an engine fail .

 

[Garak]

Originally Posted By: opus
Word is, they have removed zinc from all but diesel oils.

That is false.

 

[bvance554]

Either oil you mentioned should be good. For break in, and forever. Some people have really gotten sensitive about this 'start up flow' and what parallel you live at. Its either too much marketing, or too much BITOG gone to their head.

 

[bigt61]

Listen to the engine shop or see what GM recommends for that particular crate motor. I'd prime the oil pump before initial start - spin with old distributor shaft & a drill until you get oil pressure ......or spin with starter with plugs removed. Pre-warm oil & engine if possible - don't make your first start outside in 20 degree weather.