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Break in process

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Old May 10, 2020 | 10:20 PM
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Default Break in process

Hi fellas,

I got a 350 C3 which engine was rebuilt and bored to 355 several years ago, but very very little driven after that because was in the middle of a restoration. The previous owner passed away so their family was not able to tell me if the engine was completely broken in. They only knew that the engine was running with high zinc 20w50 and his father drove the car from time to time in the neighborhood just to move it during restoration process for at least 3 years. It has High flow heads and intake manifold, mild cam and Hooker headers.

Should I follow any special process to make sure the engine is fully and properly broken in just in case was not completed? Car is not yet registered so not sure what oil to run and how to do it in the garage without driving the car before going to pass the inspection.

BTW, when I put the car in and out the trailer it fired up really well, even w/o choke and everything seemed to be in order. However that’s all I’ve driven the car since I got it in January, now it’s finally restored and time to move forward.

Thanks for your help.
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Old May 11, 2020 | 12:35 AM
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If the family knows who rebuilt the engine that would probably be helpful. If he had a shop that typically does race engines build the motor then it was most likely at a minimum broken in before it left the shop.

If the guy rebuilt the engine himself or a small shop rebuilt it then most likely it was broken in by the previous owner.

I’m assuming it has hydraulic lifters in it. If that’s the case you’re already well past worrying about the breakin on the cam. If it wasn’t done right the damage was done long ago.

I’d say change the oil and drive it at this junction.
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Old May 11, 2020 | 01:57 AM
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Originally Posted by kossuth
If the family knows who rebuilt the engine that would probably be helpful. If he had a shop that typically does race engines build the motor then it was most likely at a minimum broken in before it left the shop.

If the guy rebuilt the engine himself or a small shop rebuilt it then most likely it was broken in by the previous owner.

I’m assuming it has hydraulic lifters in it. If that’s the case you’re already well past worrying about the breakin on the cam. If it wasn’t done right the damage was done long ago.

I’d say change the oil and drive it at this junction.
Unfortunately they don’t know who rebuild it, and no idea about hydraulic lifters but based on the amount of invoices and money invested by him in the car restoration, around $30k, I assume that he made sure that was taken care about it. As you well said if not done in the past ...in case it was needed, just the time will say it.

I will put some Valvoline VR oil and start enjoying the car after 3 months working on the full interior

Thanks
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Old May 11, 2020 | 08:12 PM
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Originally Posted by corvetero
Should I follow any special process to make sure the engine is fully and properly broken in just in case was not completed?

It shouldn't hurt anything to just assume the engine still needs to be properly broken in. You can get started on the way to inspection.

DC

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Old May 11, 2020 | 09:22 PM
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Just drive it....dont redline nor baby it I bet its fine. Read the internet enough youll be convinced you have to treat it with feather duster or it will blow up.
The days of 500 mi break ins are long gone. 50 mi and go to it!
Long break ins wont make up for bad machine work. If its gonna go it will do it either way. Winced when I ran it up to ea gear til 6800 in 4th but its fine.
(glued to a bumper of a Dinan TT M5F10 clear til 148)!

Last edited by cv67; May 11, 2020 at 09:47 PM.
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Old May 11, 2020 | 09:27 PM
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Totally. If it was built right go out and drive it like you want to. If it was not built correctly no amount of “break in” is going to matter. I’d just fill it with good oil Nd drive it.
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Old May 12, 2020 | 10:36 AM
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An old timer I asked said back in the day (model A's race car guy's) Said they'd fill the case with 5 gal of 30wt,
Start it up.
Make it idle well.
Let it run at idle all day while they kept it full of water. At the end he'd drained the case, filter the oil and put it back in at what ever amount they'd race with.
Said if you had a oil leak you knew it...…….
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Old May 12, 2020 | 11:49 AM
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Originally Posted by corvetero

I will put some Valvoline VR oil and start enjoying the car after 3 months working on the full interior

Thanks
Valvoline VR1 is good. You don't need 50 wt. I use VR1 10w 30 in mine and I beat the crap out of it.
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Old May 12, 2020 | 12:00 PM
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Originally Posted by BKbroiler
Valvoline VR1 is good. You don't need 50 wt. I use VR1 10w 30 in mine and I beat the crap out of it.
That’s the one I just put on it yesterday evening. 20w50 sounded too thick for my taste, wondering if using a 50/50 blend of both in summer in order to get like a 15w40 would be a good idea.

I will first check oil pressure with 10w30 and decide from there.
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Old May 12, 2020 | 12:26 PM
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If you're still considering performing a break-in, the linked instruction is from GM and is for a flat-tappet sbc much like a C3 motor ...
.. it contains a proper but simple break-in procedure

https://www.chevrolet.com/content/da...e-19355658.pdf

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Old May 12, 2020 | 12:53 PM
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Originally Posted by corvetero
That’s the one I just put on it yesterday evening. 20w50 sounded too thick for my taste, wondering if using a 50/50 blend of both in summer in order to get like a 15w40 would be a good idea.

I will first check oil pressure with 10w30 and decide from there.
I know it gets hot in Austin but I have made repeated 1/4 mile runs in 90 degree air at times, using 10w 30, with no problems. Just fyi.
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Old May 13, 2020 | 11:14 AM
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Originally Posted by jackson
If you're still considering performing a break-in, the linked instruction is from GM and is for a flat-tappet sbc much like a C3 motor ...
.. it contains a proper but simple break-in procedure

https://www.chevrolet.com/content/da...e-19355658.pdf

Good info. Every engine I've owned whether rebuilt or in a new car that was broken in with this or a similar procedure ended up being good engines and none had any noticeable oil consumption. Every engine I've had that was not broken in like this had noticeable oil consumption. I know what I would do.

DC
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