recommended oil weight

[jfd3604]

I have recently purchased a 71 C-10 with a 396 with the following options.
396 ci engine, Pro-Form 750 4 bbl, Street Dominator Hi-Rise aluminum intake, roller rockers, Bowtie aluminum heads, Hooker Super Comp big tube headers, HEI distributor. The engine is approaching 500 miles and I think i need to do an oil change since the engine should be broke in by now. I have not been able to locate the original builder to find out more about the cam etc...
My question to all would be
What oil weight should be used in this engine knowing the information above.
Hope to post some pictures later on.

[steelhorse]

10w30 should be fine but I would use an oil made for engines with flat tappet cams(probably have to look at specialty brands) or regular oil plus an additive.

[jfd3604]

Does it say on the oil that its made for flat tappet cams or do i need to check the website of the oil manufacturer?

[steelhorse]

It should say on the oil.

[kwmech]

I have the original 396 in my '68 with 125k and I use 20/50 valvoline

[marvgarr68]

Use rotella or delo diesel oil or you will wipe the cam. The oil for gas engines does not have enough zddp anymore. You get 15/40 in diesel oil which is fine I only use rotella only in everything I drive including my silverado 5.3. Also the diesel oil is detergent so your motor will stay clean. I have pulled down motors with high miles after I have used rotella and they are clean inside.

[bigmac73]

Originally Posted by marvgarr68

Use rotella or delo diesel oil or you will wipe the cam. The oil for gas engines does not have enough zddp anymore. You get 15/40 in diesel oil which is fine I only use rotella only in everything I drive including my silverado 5.3. Also the diesel oil is detergent so your motor will stay clean. I have pulled down motors with high miles after I have used rotella and they are clean inside.

I have to agree with the rotella, I have a new crate engine, I use the 15-40w plus a Lucas break in additive after every oil change, my manufacture recommends not using a synthetic until over 7500 miles, but personally i will just stick to the rotella with an additive

[Ricks1971]

Valvoline VR1

[marvgarr68]

Originally Posted by bigmac73

I have to agree with the rotella, I have a new crate engine, I use the 15-40w plus a Lucas break in additive after every oil change, my manufacture recommends not using a synthetic until over 7500 miles, but personally i will just stick to the rotella with an additive

Now thats what im talking about I too use the lucas breakin additive when I rebuild a engine but not every oil change just the first oil in it. I use a small bottle of stp sometimes just half of it depending on the cap of oil pan to help when they sit and oil drains off. And NEVER anything but rotella

[jfd3604]

Originally Posted by kwmech

I have the original 396 in my '68 with 125k and I use 20/50 valvoline

Which type of valvoline oil?

[KyFarm]

15/40 rotella in my 402

[mmiddle]

Wow, this is one of those questions that gets us all fighting.

If it where my engine I would run Royal Purple 10-30 in the winter and 10-40 in the summer. If you are adverse to synthetics then I would use Valvoline all-climate in the same weights. But that is just me, I'm sure you will get 400 differing suggestions and some serious stone throwing.

I have had exceptionally good results with both brands and some very bad experience from other brands.

[GASoline71]

The diesel oil is no longer the savior of flat tappet cams... It doesn't have high enough ZDDP in it as well. Been that way for almost 10 years. So you need to run an oil made for older rigs with flat tappet cams.

Look into Joe Gibbs Racing oil...

Or run off the shelf 10w30 with a ZDDP additive.

Gary

[marvgarr68]

Originally Posted by GASoline71

The diesel oil is no longer the savior of flat tappet cams... It doesn't have high enough ZDDP in it as well. Been that way for almost 10 years. So you need to run an oil made for older rigs with flat tappet cams.

Look into Joe Gibbs Racing oil...

Or run off the shelf 10w30 with a ZDDP additive.

Gary

Rotella and the others have high zddp in them. If they did not the cams would be toast in a diesel engine there is alot of pressure on the injector lobe of the cam. The cam injector lobe is what injects the fuel some 2000 psi now they are roller cams but the oils still have high zddp. Also they go 20,000 miles on a oil change. I know this because its what I do all day long.

[Ricks1971]

Rotella and the others have high zddp 1,200 parts per million and recommended level for hot rods with flat tappet cams is 1,100 parts per million. The Valvoline VR1 is 1,400 parts per million and can be used in non cat cars and trucks.

[marvgarr68]

Originally Posted by Ricks1971

Rotella and the others have high zddp 1,200 parts per million and recommended level for hot rods with flat tappet cams is 1,100 parts per million. The Valvoline VR1 is 1,400 parts per million and can be used in non cat cars and trucks.

I have used the vr1 oil and I do like it but expensive I only use when I need the heavy weight as they make in 50wt and 60 wt

[bigpaul]

I have an opinion about motor oil, changing it frequently is more important than brand or viscosity. A few years back my employer gave me a 96 jeep with 100,000 miles. I went to my friends place for an oil change. He put in a Napa filter and 10w30 Napa oil. I didn't much like that. At 200,000 miles he was still putting in a Napa filter and Napa oil. When I turned it in, it had 250,000 mile with, you guessed it. I changed oil every 3,000 miles and the valve cover was never off of that engine. The last time I ask one of the company mechanics he said the Jeep now had 350,000. I am not promoting Napa oil or filter, but the concept of regular changes.

['68OrangeSunshine]

I would go with Valvoline Racing, since it has the ZDDP. Or use STP 4 Cylinder Oil Booster [w/ high ZDDP] with other oils. I like 20W-50 weight for a hotter climate -- I live in Tucson. Or straight SAE 30. [My 292 L6 likes that stuff.]
There are also some other ZDDP additives on the market that I haven't used myself.
If you can find new-in-the-box old oil marked series 'SL' or earlier, that's OK. Series 'SM' or later needs more ZDDP for our vintage engines.
Frequent oil changes are also a lot less expensive in overhaul costs, over all. I got 250,000 miles out of a 292 by changing oil every 2000 miles.

[mmiddle]

BigPaul:
Napa oil is private label Valvoline All-Climate (Ashland Oil Co.) and the Napa filters are private label WIX. The same goes for CARQUEST. Both are top shelf stuff.

[Ricks1971]

https://shop.valvolineglobal.com/pro...oil-sae-20w-50

[Rabe]

I use Castrol GTX Classic 20w-50, it’s got the proper zinc additive. My second choice would be Joe Gibbs DRIVEN Hot Rod Oil, it too has the zinc. Both oils have high reviews

['68OrangeSunshine]

I just switched the oil in the 350 in my '71 GMC Jimmy from 20W-50 to SAE 30 Valvoline VR1. Same oil I use in my '68 C/10 Stepside's 292. Logistics, mainly. One oil to rule them all. But also an old school engine works best with old school oil.
Hey, my last comment in this thread was 11 years ago.

[Palf70Step]

I typicallly use the vavoline vr1. Rotella is good. But still needs zddp additives to give it sufficent amounts for the traditional non roller cam lobes

[70cst]

lubriplate super gpo 15w-40

[PbFut]

Everyone is worked up on the zink but does the engine have flat or roller lifters? What about bearing clearance. Thicker oil is great for the looser builds of days past. Go too thick on a modern tight build and you will be sorry. Most above suggestions are not taking into account your engine may be very different than theirs. All the zinc in the world will not help a tight bearing in a cold engine with high viscosity oil. If you can't find the engine specs, I would run high zinc with moderate viscosity. Run a Blackstone report when you change and continue till you find what works best.