What's the best oil for a old tired engine?

[WarBeard]

So I just got this 74 Custom/10 and I want to replace all the fluids and I was wondering what would be the best oil for an old and tired 350?

I don't know how many miles are on this engine and I believe it to be the original 350 2bbl I just want as much life out of it as possible.

I live In eastern Arizona and rarely see outside temps over 90 degrees in the summer and it got to 16 below last winter.

[cjlinkster]

As long as the engine isn't showing signs of excessive blow-by, I would run 10-40w. Some people like to run diesel rated oil like Rotella. I may switch to it at my next oil change. I have been using Rotella in all of my small engines over the last 4 years.

I would not run anything crazy like 20-50w.

[WarBeard]

It fires right up and I don't see any smoke at all. The tailpipe is not oily.

The 10-40 is Rotella? Or is Rotella a different weight?

What does Diesel oil do for old engines?

[85Bowtie]

Rotella is 15w-40. It has more zinc content which is good for flat tappet cams in older engines.

[lilpoindexter]

I use straight 30wt in my '78 straight six. I have no idea how many miles are on the engine. Of course it rarely gets into the high 90's here, and the coldest I've ever seen it in the winter is about 36 for the overnight low.

[78 Big10 454]

I strictly use 30W in my '78.

[S10Fan]

Originally Posted by 85Bowtie

Rotella is 15w-40. It has more zinc content which is good for flat tappet cams in older engines.

From what I've read, zinc has been removed from most all oil, including Rotella. I use regular branded oil and add ZDDP with each oil change.

[Hazieview]

Originally Posted by S10Fan

From what I've read, zinc has been removed from most all oil, including Rotella. I use regular branded oil and add ZDDP with each oil change.

Posted via Mobile Device

[85Bowtie]

Originally Posted by S10Fan

From what I've read, zinc has been removed from most all oil, including Rotella. I use regular branded oil and add ZDDP with each oil change.

No, they just have lower concentrations of zinc. Diesel oil still has higher zinc concentrations even after the use of catalytic converters on diesels.

[S10Fan]

Originally Posted by 85Bowtie

No, they just have lower concentrations of zinc. Diesel oil still has higher zinc concentrations even after the use of catalytic converters on diesels.

Thanks, good information.

[Dunenutt]

10w30, or 30wt. I would'nt do anything weird, like diesel oil, or synthetic to a high mileage motor. The motor has probably collected some gunk over the years, and it's best if it just stays where it is. If you break the gunk loose, you can plug the oil pickup and destroy it.

[WarBeard]

ZDDP....Is this something I can get from Napa or Autozone?

Will 30w work in cold climates...We just got our first snow today

[S10Fan]

Originally Posted by motomech

ZDDP....Is this something I can get from Napa or Autozone?

I haven't seen it at either place. I buy mine in 4oz bottles on eBay. It's not cheap but neither are engine rebuilds.

[kp110477]

If you want to know WAY more than you ever thought you would know about oil, read this article. It's written really really well, as are the rest of his tech articles. It's on Pirate4x4.com, Here's the link for the whole tech articles page

[85Bowtie]

Originally Posted by motomech

ZDDP....Is this something I can get from Napa or Autozone?

Will 30w work in cold climates...We just got our first snow today

Just buy a bottle of Comp Cams 152 break-in lube from Summit or wherever you can find it. STP Oil Treatment also has "some" zinc in it as well.

However, if it's a tired worn out engine....who cares what oil you run in it? Zinc acts as a lubricant to keep your cam lobes from going flat. As far as "breaking of gunk and plugging your pick-up"....what? If the engine is at the point that your worried something might "come loose" and plug your pick-up, you're ready for a rebuild.

Just run whatever you want in it, it's not going to blow up or anything. At the worst you'll wipe a cam lobe and end up with a crappy running engine which you would have to rebuild anyway.

[WarBeard]

I think Im going to get some Rotella and let it ride. I just bought the truck so im not ready to rebuild the engine yet. I still need it to get me a few loads of wood for the winter.

[spudz]

Rotella USED to have zink in it and that was good for keeping things nice and happy. BUT they took most of the zink out of it a couple years ago... Its no more helpfull then some 20w50 now

[ChevyC102007]

I use Castrol Hi-Mileage or Valvoline High Mileage in my wifes 01 'Ram but I think that has a roller cam in it. I used the Castrol in my '71 with no problems (still wiped a cam lobe in a 39+ year old motor. Bound to happen). Just my .02

[85Bowtie]

Originally Posted by spudz

Rotella USED to have zink in it and that was good for keeping things nice and happy. BUT they took most of the zink out of it a couple years ago... Its no more helpfull then some 20w50 now

Another one....

Rotella has MORE "zink" (zinc) than other oils. Actually, ANY diesel oil is going to have more zinc content than other conventional oils, even after they cut back on the zinc content.

The zinc concentration in Rotella is something like 1200-1400 ppm VS. ~600 ppm (or less) for non-diesel oils. So yes, it WAS higher a few years ago, but ~1200ppm is still plenty for an old engine.

Besides, what does zinc content have to do with weight of the oil???

This guy has a worn out old engine. Just run it.

[flamingbig10]

My dads 350 has 270,000 it only burns and leaks a qt every 3,000, still has good oil pressure, and the intake or valve covers never been off, been putting high millage 15w40 since 200,0000

[tucsonjwt]

I would not spend anything but minimum money on good oil for an old engine. I buy name brand oil on sale by the case at the auto parts store. I currently have 2 cases of Valvoline left which were purchased for $1 per quart about 2 years ago. I use 10w40 in my 83 BB - I think that would be best for you also. I buy oil and air filters the same way and stock up. My BB takes 7 quarts.

[Dunenutt]

"As far as "breaking of gunk and plugging your pick-up"....what? If the engine is at the point that your worried something might "come loose" and plug your pick-up, you're ready for a rebuild."

Sorry to offend...

Throw six quarts of Royal purple in a 100,000 mile Penzoil motor, drive it for a couple hundred miles, then get back to me.

I have not seen his motor, but have rebuilt quite a few nasty ones. I have a couple of favorites... Tranny fluid added to remove gunk, and diesel fuel added to do the same! Both engines, the pickup was plugged solid.

It was just a "worst case warning", just to be nice.

[85Bowtie]

Originally Posted by Dunenutt

Throw six quarts of Royal purple in a 100,000 mile Penzoil motor, drive it for a couple hundred miles, then get back to me.

Sure...I'm going to buy $7/qt Royal Purple and put it into a 100,000 mile engine and then report back to you just to prove something I already know.... Or were you foolish enough to actually buy $40 worth of Royal Purple and put it into a worn out engine?

Throwing transmission fluid into the crankcase is a little different than trying a different oil....don't you think? Either way, anything ready to "come loose" will do so without worrying about what type of oil your running through the engine, regardless of the amount of detergent. Heat, pressure and thermal expansion have a little more persuasion in breaking things loose than your oil will.

[Dunenutt]

My original post said " Dont do anything weird", and my point was it may do more harm than good.

I digress reluctantly...

[electrician42]

I run only 5w-30 penzoil with ac filters on my 350 ,5.3 and in the 6.0 i just purschased and never a problem