Engine Oil Recommendations

[byates2]

Got a 67 C10. A 350 block bored about 33 over with a racing cam. It is a new engine, hasnt been broken in yet, been sitting for a year but started periodically and driven a little.

What oil weight should i use? Conventional or Synthetic?

[Rufas]

Everything I've heard is NOT to use synthetic oil for a new engine break in. Get your self some convention break in oil with zinc in it. I assume you have a flat tappet cam, zinc additive is needed during break in. Synthetics don't have enough zinc and could cause you cam to go 'flat'.

In this motor


I used this break in oil

https://www.summitracing.com/parts/edl-1070

[byates2]

Now that is gorgeous. I will look into that then. Just got done with a new Ididit column so its just about road worthy. 7 years in the making so want everything done right

['68OrangeSunshine]

Non-Detergent SAE 30 weight [non-synthetic] with a bottle of GM EOS engine oil suppliment for the first 500 miles. Keep the RPMs low.

[Step'67]

Originally Posted by '68OrangeSunshine

Non-Detergent SAE 30 weight [non-synthetic] with a bottle of GM EOS engine oil suppliment for the first 500 miles. Keep the RPMs low.

This. The non-synthetic oil recommendation generally isn't due to lack of zinc/phosphorus (which most oils today, including conventional, do indeed lack and is necessary in flat-tappet engines), but the detergents in synthetic oil are supposed to cause issues with the rings seating and other mating surfaces getting to know one another.

Just a couple weeks ago, my cam wiped a lobe after several years of zero issues despite running one of Amzoil's high-zinc formulations. For the new cam and lifters break-in, I ran Valvoline VR1 SAE 30 which is a non-street legal, high-zinc race oil, plus some zinc additive. Brad Penn's break-in oil also carries a high recommendation. A dedicated break-in oil like Penn's or Amzoil's (what I used for the first build) in my mind would be better as break-in additives can degrade/interfere with the base oil's additive package. Though I do know people have had good luck with GM's EOS as '68OS recommended.

I will be stepping up to Amzoil's ZRod formulation that has a higher zinc content for the remainder of my engine's life instead of their standard high-zinc line. Just be sure to run a high-quality, high zinc/phosphorus oil for the engine's life, not just during break-in.

[Rufas]

Originally Posted by Step'67

This. The non-synthetic oil recommendation generally isn't due to lack of zinc/phosphorus (which most oils today, including conventional, do indeed lack and is necessary in flat-tappet engines), but the detergents in synthetic oil are supposed to cause issues with the rings seating and other mating surfaces getting to know one another.

Just a couple weeks ago, my cam wiped a lobe after several years of zero issues despite running one of Amzoil's high-zinc formulations. For the new cam and lifters break-in, I ran Valvoline VR1 SAE 30 which is a non-street legal, high-zinc race oil, plus some zinc additive. Brad Penn's break-in oil also carries a high recommendation. A dedicated break-in oil like Penn's or Amzoil's (what I used for the first build) in my mind would be better as break-in additives can degrade/interfere with the base oil's additive package. Though I do know people have had good luck with GM's EOS as '68OS recommended.

I will be stepping up to Amzoil's ZRod formulation that has a higher zinc content for the remainder of my engine's life instead of their standard high-zinc line. Just be sure to run a high-quality, high zinc/phosphorus oil for the engine's life, not just during break-in.

Very good advise.

['68OrangeSunshine]

Originally Posted by Step'67

This. The non-synthetic oil recommendation generally isn't due to lack of zinc/phosphorus (which most oils today, including conventional, do indeed lack and is necessary in flat-tappet engines), but the detergents in synthetic oil are supposed to cause issues with the rings seating and other mating surfaces getting to know one another.

Just a couple weeks ago, my cam wiped a lobe after several years of zero issues despite running one of Amzoil's high-zinc formulations. For the new cam and lifters break-in, I ran Valvoline VR1 SAE 30 which is a non-street legal, high-zinc race oil, plus some zinc additive. Brad Penn's break-in oil also carries a high recommendation. A dedicated break-in oil like Penn's or Amzoil's (what I used for the first build) in my mind would be better as break-in additives can degrade/interfere with the base oil's additive package. Though I do know people have had good luck with GM's EOS as '68OS recommended.

I will be stepping up to Amzoil's ZRod formulation that has a higher zinc content for the remainder of my engine's life instead of their standard high-zinc line. Just be sure to run a high-quality, high zinc/phosphorus oil for the engine's life, not just during break-in.

Forty years ago, that was the break-in formula for the first 500 miles. It worked then. These engines are the same, so it should work now. That engine ran 250,000 miles from 1977 to 2002. At which time I rebuilt another one using the same kinda stuff. I also ran it on Valvoline SAE 30 Racing oil, gradually going to 40 weight, 50 weight, by that time it was time to rebuild. I changed oil at 2000 mile intervals.
The ''new'' engine I run on Valvoline VR1 SAE 30 Weight Racing Oil, as well, but sometimes 20W-50 in the winter. I live in Arizona.

Step'67: what caused the lobe wiping of your cam?

[Step'67]

Originally Posted by '68OrangeSunshine

Step'67: what caused the lobe wiping of your cam?

The #8 exhaust lifter began chattering. Upon disassembly, the lifter was dished while the cam lobe had rounded and began to grind off. From other's experience, it doesn't seem typical that a cam lobe fails a couple years after initial break-in due to material defects. After digging into Amzoil's product data sheets, and user posted Blackstone lab reports, I'm leaning towards it being caused by my oil choice. According to the lab analysis, the Amzoil Premium Protection line I was using carries a zinc concentration of approximately 1000ppm (around 200ppm more than the current oils on the market). However, for a hotter than stock cam with fast lift rates and high lift/duration, an oil with 1200-1400ppm is recommended by Amzoil. This is where their ZRod and higher race oils fall, and why I'm switching to it to hopefully prevent it from happening again.

['68OrangeSunshine]

I had an exhaust valve spring break on #4 cylinder in 2015, we figured it was a fluke and my machinist gave me a used replacement. Then early this year, another one broke on #1. This time we replaced all the valve springs with new Sealed Power springs. Running better than before. Have not noticed cam problems, Vacuum gauge reads 17 - 17.5'' Hg, steady and normal. This is a '68 L6 292, bored .030 over.

[toolboxchev]

Originally Posted by Step'67

This. The non-synthetic oil recommendation generally isn't due to lack of zinc/phosphorus (which most oils today, including conventional, do indeed lack and is necessary in flat-tappet engines), but the detergents in synthetic oil are supposed to cause issues with the rings seating and other mating surfaces getting to know one another.

Just a couple weeks ago, my cam wiped a lobe after several years of zero issues despite running one of Amzoil's high-zinc formulations. For the new cam and lifters break-in, I ran Valvoline VR1 SAE 30 which is a non-street legal, high-zinc race oil, plus some zinc additive. Brad Penn's break-in oil also carries a high recommendation. A dedicated break-in oil like Penn's or Amzoil's (what I used for the first build) in my mind would be better as break-in additives can degrade/interfere with the base oil's additive package. Though I do know people have had good luck with GM's EOS as '68OS recommended.

I will be stepping up to Amzoil's ZRod formulation that has a higher zinc content for the remainder of my engine's life instead of their standard high-zinc line. Just be sure to run a high-quality, high zinc/phosphorus oil for the engine's life, not just during break-in.

If look thoroughly thru the 540 rat blog you will see he comes to one conclusion while downplaying the ZDDP additives.

Film Strength. I have been running VR1 for over 70k now on a top end rebuild with a very mild Comp Cam. So far so good!

[s10mk]

I didn't see it in the thread, but is the OP running a flat tappet or a roller cam?

[71CHEVYSHORTBED402]

While I'd be tempted to run with some of these recommendations, there's always this. Unless I'm missing the point (it's a little long), the guy's test results do not support zinc or break in oil. https://540ratblog.wordpress.com/201...-test-ranking/

Beautiful engine.

[truckster]

My machine shop guy says no synthetics for the first 3 to 5 thousand miles. He says the rings won't seat properly.

[Rufas]

Originally Posted by 71CHEVYSHORTBED402

While I'd be tempted to run with some of these recommendations, there's always this. Unless I'm missing the point (it's a little long), the guy's test results do not support zinc or break in oil. https://540ratblog.wordpress.com/201...-test-ranking/

Beautiful engine.

I think you will find most cam manufactures recommend a zinc conventional oil for flat tappet cam break in. Zinc is not required on most of today's engines that are roller type tappets.

http://www.cranecams.com/whats_newview.php?s_id=36

http://howardscams.com/i-24078662-ho...-additive.html

http://www.hotrod.com/articles/ccrp-...ak-in-new-cam/

I didn't run oil with enough zinc additive in this 468 BBC with flat tappets. Cam went flat in less then 6,000 miles. It now has a roller cam in it.

[71CHEVYSHORTBED402]

Originally Posted by Rufas

I think you will find most cam manufactures recommend a zinc conventional oil for flat tappet cam break in. Zinc is not required on most of today's engines that are roller type tappets.

http://www.cranecams.com/whats_newview.php?s_id=36

http://howardscams.com/i-24078662-ho...-additive.html

http://www.hotrod.com/articles/ccrp-...ak-in-new-cam/

I didn't run oil with enough zinc additive in this 468 BBC with flat tappets. Cam went flat in less then 6,000 miles. It now has a roller cam in it.

When you say not enough Zinc, do you mean for the break-in period and/or ongoing? I used Zinc additive once. That link scared me off and I couldn't change the oil fast enough. Differences of opinions, and personally, I'm not settled on anything.

I can only speak for my 71 402 with 396 heads (larger ports). The engine was rebuilt in 93. I don't remember what oil we used, but I do recall changing it after say 500 miles. Soon after I used Valvoline Durablend only. Usually 10-40, but it really hummed on 20-50. I recently switched to Mobil 1 synthetic 5-30. Only tangible noticeable difference is the oil leaks nearly stopped. My engine sure liked that Durablend, but the gaskets didn't.

After we installed the motor we realized we didn't have a tach. "Too far" to any store, we took a dead highway on a straight line (beauty of Dayton Nevada) with steady acceleration, and guessed at the RPMs. Really, my bud and I were pretty comfortable with the situation.

There's now 40K on the engine. Purrs like a kitten, great response and power. The oil on the dipstick is always clear.

[Rufas]

Originally Posted by 71CHEVYSHORTBED402

When you say not enough Zinc, do you mean for the break-in period and/or ongoing? I used Zinc additive once. That link scared me off and I couldn't change the oil fast enough. Differences of opinions, and personally, I'm not settled on anything.

I can only speak for my 71 402 with 396 heads (larger ports). The engine was rebuilt in 93. I don't remember what oil we used, but I do recall changing it after say 500 miles. Soon after I used Valvoline Durablend only. Usually 10-40, but it really hummed on 20-50. I recently switched to Mobil 1 synthetic 5-30. Only tangible noticeable difference is the oil leaks nearly stopped. My engine sure liked that Durablend, but the gaskets didn't.

After we installed the motor we realized we didn't have a tach. "Too far" to any store, we took a dead highway on a straight line (beauty of Dayton Nevada) with steady acceleration, and guessed at the RPMs. Really, my bud and I were pretty comfortable with the situation.

There's now 40K on the engine. Purrs like a kitten, great response and power. The oil on the dipstick is always clear.

On going. I was using Valvoline VR1 SAE 30 and an ounce of zinc additive. I don't remember the additive name, that was four years ago. But that didn't work out so good.

[saxart]

Is this the proper GM zinc additive to use in our flat-tappet engines?

http://www.jegs.com/i/Chevrolet-Perf...62587/10002/-1

It says "use as assembly lube only, not as oil additive", but I'm wondering if maybe that is just to keep things legal? I know there are a million threads on this stuff, but the part numbers have changed, so I just want to make sure I'm getting the right stuff.

Thoughts?

['68OrangeSunshine]

Originally Posted by saxart

Is this the proper GM zinc additive to use in our flat-tappet engines?

http://www.jegs.com/i/Chevrolet-Perf...62587/10002/-1

It says "use as assembly lube only, not as oil additive", but I'm wondering if maybe that is just to keep things legal? I know there are a million threads on this stuff, but the part numbers have changed, so I just want to make sure I'm getting the right stuff.

Thoughts?

Can't say for sure, by I'll buy your legality theory. If they flat-out stated it was for break-in, then guys with catalytic converters might use it too, waste their cats and wanna sue GM.
Why do they still call it EOS?

[Step'67]

Glad nothing else got damaged and that you got it sorted! You're running the VR1 on a regular basis? I know it is supposed to be a good high-zinc oil for flat tappets, and it is literally half the cost of the Amzoil. If you are, do you run the conventional or the full synthetic version?

[TBohne]

I am breaking in a 383, have about 300 miles on it, what oil should I run after the first 500 mile break in?

['68OrangeSunshine]

Originally Posted by TBohne

I am breaking in a 383, have about 300 miles on it, what oil should I run after the first 500 mile break in?

I like Valvoline 30 Weight Racing [VR1]. I live in a climate similar to yours, [Tucson, AZ].

[engineer_gregh]

I only use Comp Cams break in oil, 10W-30. I have about 8K miles on my rebuilt 1971 402 with 1966 396 heads. I called and spoke to Comp Cams tech department. The only difference in their break-in oil and their regular oil is the amount of zinc. I don't run a catylatic converter so no issues there. Just my .02 cents

[GRX]

At this point it should be mentioned that ZDDP is acidic and adding too much will turn the oil corrosive. This is cause of many new cam failures when people add more than recommended amount of Zinc additive thinking more is better.