What Type of Oil To Use

[rdhowe2006@yahoo.com]

I have a 1970 Chevy C-10 LWB Step Side Pick Up. It has a 250 straight six. What type and grade of motor oil should I put in it? Also any idea of how many quarts it holds with filter? Any help would be appreciated.

[Alex V.]

If it's a healthy engine with decent oil pressure (at least 10-15 pounds at idle, 35-40 in the highway) I'd run 10w40 synthetic blend. If oil pressure is lower or it gets used hard much, bump up to 15w40. I really like Valvoline MaxLife and prefer Wix filters. I believe it'll hold 5 qts. with filter.

[71CHEVYSHORTBED402]

Mobile 1 5W30 Full Synthetic

[1968aj]

If it is older engine it is not a good idea to switch over to synthetic.

[rdhowe2006@yahoo.com]

Yes it is the original engine. 122,000 miles on the engine.

[mike16]

Originally Posted by 1968aj

If it is older engine it is not a good idea to switch over to synthetic.

back in the 80's that may have been the case. now, I dont think its a problem currently. I use mobile one beginning 6 years ago in my 72 when it had only 71K miles on it. No problems at all.

[Grumpy old man]

Castrol 20-50 classic xl made for these engines and has never given me any problems

[1968aj]

I know of one guy who switched over to synthetic in a well used motor it began to leak at several gaskets. he had to pull the motor and install new gaskets.

[Custom/20]

I use Joe Gibbs HR2 10w30 with a six filter. 4 quarts in the pan and 1 in the filter.

[Sicklajoie]

I've always run Kendall 10w-40. It's all but impossible to find in stores now so I buy it online.

[TheFix]

Originally Posted by Grumpy old man

Castrol 20-50 classic xl made for these engines and has never given me any problems

Where do you get that stuff at? I can only find it on Castrols website. No distributors.

[fwayne]

I've switched countless engines from traditional to full synthetic and blends and NEVER had problems with leaks. In fact the opposite was true. I've had small leaks go away after using synthetics. Leaks happen because the seals are bad. The truth and science is that synthetics are superb in every regard over traditional oil. The only issue is the lack of zinc and lead which protected the camshaft and lifters. But thats gone form traditional oils too. In fact you may hasten the wear on your old engine by continuing to use traditional oils, which lack protections the original engine oils had due to the lead in the fuel. There is a reason modern engines do so well with synthetics, its far and away a superior lubricant, wear prevention, stable viscosity, and resistance to build-up. You can also drop from the heavy viscosity as rdhowe stated. Just watch the pressures, you want at least 10 PSI for every 1000 RPM, that ole six will feel spirited due to friction loss if you can get away with say 5w-30 or 10w-40

[davepl]

Follow the manual. It was right then for these motors, and it's right now for these motors. Oil has improved (and devolved in some ways too), but viscosity is viscosity.

[Ironangel]

Whatever oil you use, it needs to have "Zinc" in it! Also known as (ZDDP) "Zinc Phosphate" or "Zinc Dithiophosphate"...Google those names and do your own research. I will say this, any flat tappet motor using alloys and tolerances from yesteryear needs a certain degree of zinc (ZDDP) to survive...

[71CHEVYSHORTBED402]

Originally Posted by Ironangel

Whatever oil you use, it needs to have "Zinc" in it! Also known as (ZDDP) "Zinc Phosphate" or "Zinc Dithiophosphate"...Google those names and do your own research. I will say this, any flat tappet motor using alloys and tolerances from yesteryear needs a certain degree of zinc (ZDDP) to survive...

Well, I used a ZDDP additive for about 500 miles. After reading the following provided by another poster, I changed my oil the very next day. I now run Mobile 1 5W30. https://540ratblog.wordpress.com/

As far as leaks go, I used Durablend from 1993-2015. The engine was rebuilt in 1993. Yeah it leaks, but never enough to have to add oil. I would imagine it's the rear main, but I'm no expert. The valve covers are fine. It started leaking almost right away following the rebuild. Oil related? I'm guessing not.

[1968aj]

believe what you want. I have seen motors that have been run on standard oil that were switched to synthetic. it will find leaks that were no visible because of sludge build up around gaskets .it has a higher detergent content or less viscosity or some reason that causes this. maybe not in every case but I have seen it happen.

[71CHEVYSHORTBED402]

Originally Posted by 1968aj

believe what you want. I have seen motors that have been run on standard oil that were switched to synthetic. it will find leaks that were no visible because of sludge build up around gaskets .it has a higher detergent content or less viscosity or some reason that causes this. maybe not in every case but I have seen it happen.

I gots to thinking about it and suspected you're right. I'm replacing my rear main with the rebuild, hopefully that stops the leak. Other than that and the valve covers, I'm not aware of any additional gaskets with my current edgukation. At any rate, check this out: http://auto.howstuffworks.com/switch...hetic-oil1.htm

[RickDeVon]

Valvoline 10w30...

[Alex V.]

I've done a respectable amount of reading on ZDDP, and here's what I'm currently doing with my old Chevy V8's that has worked thus far:

During break-in, conventional oil with a full dose of ZDDP additive or ZDDP-rich break-in lube. Afterward, syn blend (Schaeffer's 10w30 in my truck's 120,000 mi. 454, Valvoline 10w40 in my 'Burb's history-unknown 350) with no, or only a half bottle, of ZDDP additive.

My dad's '86 K20 racked up 361,000 mi. before he quit driving it in about '08 - it always had conventional 10w40 (20w50 in hot weather, IIRC) with no zinc added and it never showed noticeable cam problems, so for our stock, low-perf (aka, low valve spring pressure) truck engines I think ZDDP is as unnecessary as it would be in any old engine, and if they can do what some of them did on conventional oils back then today's synthetics (a superlube in comparison) are overkill any way you slice it.

[70cst]

Here is my choice


https://www.lubriplate.com/Products/...otor-Oils.aspx

[cdowns]

a used engine eith 125000 miles the damage is already done no amt of zinc or kryptonite will do anything to magigicly save it

[toolboxchev]

52 k on top end rebuild, Valvoline VR-1 the whole time. And headed out to work this morning.

[trac209]

Originally Posted by 71CHEVYSHORTBED402

Well, I used a ZDDP additive for about 500 miles. After reading the following provided by another poster, I changed my oil the very next day. I now run Mobile 1 5W30. https://540ratblog.wordpress.com/

As far as leaks go, I used Durablend from 1993-2015. The engine was rebuilt in 1993. Yeah it leaks, but never enough to have to add oil. I would imagine it's the rear main, but I'm no expert. The valve covers are fine. It started leaking almost right away following the rebuild. Oil related? I'm guessing not.

That high zinc thing people were saying you needed in flat tapped cams was nothing more than marketing snake "oil" created to sell a product. I've run flat tapped cams from old to new installs and have never used a zinc oil and haven't had one issue.

[Grumpy old man]

This debate has gone on forever , use whatever oil makes you happy and toss in some stp oil treatment , the young guys don't understand the old engines and the old guys the same for new , so rather than play mines better be happy with what your using .

[Alex V.]

The link 71chevyshortbed402 posted is interesting. I didn't read every word, but from scanning it I don't see any holes in his logic and, coupled with what I've seen with my own eyes, am persuaded to put some stock in his findings. Interesting that several weights of Valvoline MaxLife make it into the top 25? on the EP protection list.

Here's what I know - Valvoline is, and has been for along time, regarded as a high-quality oil. I've seen two different 350's, designed in the same era as your inline six, go past 350,000 miles without indications there was anything lacking in the oil used in them, and countless other cars with all kinds of different engines run many, many wear-free miles with 10w30 or 10w40 Valvoline products. I'm not going to stand on my soap box (like, say, the ZDDP preachers) and say it's obviously and indisputably the best, but I have enough "real world R&D" with it that I trust it as much as any widely available lubricant. Use what your conscience, influenced by our opinions and your own research, will be most at rest with, but for me it's Valvoline MaxLife.