Brake in oil question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**7D2N** · 08-31-2021, 08:32 PM

I had the engine for my Blazer rebuilt and was broke in on a stand. I still have the brake-in oil engine and start it regularly. Should I drain it and add new oil or keep running because it's not road-ready.

**AussieinNC** · 08-31-2021, 09:06 PM

I would leave it in there...

If the rebuilt engine is a flat tappet cam, any replacement oil MUST contain a ZDDP oil additive, as modern oil do not have Zinc content due to it causing catalytic convertor failures.

If the engine has a roller cam and lifters you would be fine with a modern oil...

Have fun!

**truckster** · 08-31-2021, 11:38 PM

Generally you'll run 500 miles before the first oil change. Unless you're running it for a long time each time you start it, it's going to take a while to equal as many running hours. Plus, putting a load on the engine helps break it in. I'm with Aussie; leave it in there until you get the engine in the truck and then make sure you use the proper oil when you do change it.

geezer#99 · 09-01-2021, 11:33 AM

Compared to a lot of other things, Oil is cheap!
I’ve always changed it after break in. Partly from piece of mind. Mostly to look for metal in the oil and filter.

GASoline71 · 09-02-2021, 04:55 PM

Quote:

Originally Posted by geezer#99

Compared to a lot of other things, Oil is cheap!
I’ve always changed it after break in. Partly from piece of mind. Mostly to look for metal in the oil and filter.

Me too. Since this oil ZDDP fiasco started, I now break in a flat tappet engine with break-in oil, drain it, change oil and filter and use ZDDP additive, and then change oil and filter and add ZDDP again after 500 miles.

Gary

**7D2N** · 09-02-2021, 09:51 PM

It was broke in with good grade oil and the motor is now in the blazer. I start it fairly regular and I move it around some, but it's not ready for the road yet.
new oil can't hurt too much.
Thanks guys.

**7D2N** · 10-09-2021, 04:47 PM

Okay, guys. I drained the original break-in oil (mainly to see if I had metal stuff) and it showed to be really clean. My question If it was broken in with 30wt and because they sent me 20-50wt instead can I run it.
Did I mention it was in the Blazer.

Thanks for any info.

geezer#99 · 10-09-2021, 05:15 PM

You live in cold country.
No need for heavy oil.
I’d run 10w30.

**7D2N** · 10-09-2021, 05:24 PM

Thanks geezer. I'll have to send the Lucus 20-50 back and get the 30wt.

**The Rocknrod** · 10-10-2021, 05:57 AM

10W30 is suitable for varying temperature ranges and also works well in cold weather. Not SAE 30 or 30W.

toolboxchev · 10-12-2021, 11:14 PM

Valvoline VR1, hands down a great oil in my book. 100k on my rebuilt engine with it. Flat tappet cam.

GASoline71 · 10-14-2021, 11:15 AM

I used to run straight SAE 30wt in all my rigs until about the mid 1990's. Now I run 10w30wt in all my rigs.

30wt for one is hard to find. It is also specified for break-in oil because it used to be a non-detergent oil. Not so much anymore. Don't run 30wt in your rig. Your lifters and bearings will thank you for using 10w30 in cold weather.

Gary

08-31-2021, 08:32 PM	#1
7D2N Senior Member Join Date: Aug 2007 Location: Morgan County Utah Posts: 645	Brake in oil question I had the engine for my Blazer rebuilt and was broke in on a stand. I still have the brake-in oil engine and start it regularly. Should I drain it and add new oil or keep running because it's not road-ready. __________________ Just for the fun of it

08-31-2021, 09:06 PM	#2
AussieinNC Moderator Join Date: Jun 2017 Location: Cherryville, NC Posts: 2,155	Re: Brake in oil question I would leave it in there... If the rebuilt engine is a flat tappet cam, any replacement oil MUST contain a ZDDP oil additive, as modern oil do not have Zinc content due to it causing catalytic convertor failures. If the engine has a roller cam and lifters you would be fine with a modern oil... Have fun! __________________ Family and country before all others... 2006 Chevy Silverado (Daily Driver) 2012 Chevy Equinox

08-31-2021, 11:38 PM	#3
truckster Senior Member Join Date: Jan 2001 Location: Orem, Utah Posts: 7,794	Re: Brake in oil question Generally you'll run 500 miles before the first oil change. Unless you're running it for a long time each time you start it, it's going to take a while to equal as many running hours. Plus, putting a load on the engine helps break it in. I'm with Aussie; leave it in there until you get the engine in the truck and then make sure you use the proper oil when you do change it. __________________ I have sworn upon the altar of God, eternal hostility against every form of tyranny over the mind of man. - Thomas Jefferson

09-01-2021, 11:33 AM	#4
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,512	Re: Brake in oil question Compared to a lot of other things, Oil is cheap! I’ve always changed it after break in. Partly from piece of mind. Mostly to look for metal in the oil and filter.

09-02-2021, 09:51 PM	#6
7D2N Senior Member Join Date: Aug 2007 Location: Morgan County Utah Posts: 645	Re: Brake in oil question It was broke in with good grade oil and the motor is now in the blazer. I start it fairly regular and I move it around some, but it's not ready for the road yet. new oil can't hurt too much. Thanks guys. __________________ Just for the fun of it

10-09-2021, 04:47 PM	#7
7D2N Senior Member Join Date: Aug 2007 Location: Morgan County Utah Posts: 645	Re: Brake in oil question Okay, guys. I drained the original break-in oil (mainly to see if I had metal stuff) and it showed to be really clean. My question If it was broken in with 30wt and because they sent me 20-50wt instead can I run it. Did I mention it was in the Blazer. Thanks for any info. Attached Images __________________ Just for the fun of it

10-09-2021, 05:15 PM	#8
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,512	Re: Brake in oil question You live in cold country. No need for heavy oil. I’d run 10w30.

10-09-2021, 05:24 PM	#9
7D2N Senior Member Join Date: Aug 2007 Location: Morgan County Utah Posts: 645	Re: Brake in oil question Thanks geezer. I'll have to send the Lucus 20-50 back and get the 30wt. __________________ Just for the fun of it

10-10-2021, 05:57 AM	#10
The Rocknrod Moderator Join Date: Aug 2011 Location: China Spring, TX Posts: 7,280	Re: Brake in oil question 10W30 is suitable for varying temperature ranges and also works well in cold weather. Not SAE 30 or 30W. __________________ Master Chief, US Navy, Retired 1964 C10 Step-side Short Bed - In Progress 2009 2500HD Duramax LTZ 1948 GMC Panel 1956 Big Window Stepside 1953 5 Window Chevy Stepside 1932 Coupe New Seat Foam for Bench Seats?

10-12-2021, 11:14 PM	#11
toolboxchev Registered User Join Date: Jul 2015 Location: 2nd left past the stump on a dirt road. Posts: 2,629	Re: Brake in oil question Valvoline VR1, hands down a great oil in my book. 100k on my rebuilt engine with it. Flat tappet cam.



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