Oil viscosity

[661buster1963]

As I close in on what seems like a 20 year rebuild some things I used to do are a little foggy. I have had a bronco, mustang, falcon, or fairlane (at times 2 or 3) my whole life. I have some break in oil for the virgin 71 351w I rebuilt by punching 20 over. A torquey voodoo cam carb and electronic ignition v8 with a planned nv3550 trans. I have Joe Gibbs break in oil in it now. Back in the day I almost always ran 10w-30 in every small block ford I ever had. My dad has always recommended I go to 10w-40 for a little higher hot end viscosity. I might be a mechanical engineer with masters degree from cal
Poly but still not sure why a guy would move to 10w-40. I plan to run 1200 Ddp oil forever, change it twice a year regardless of miles. I got too
Much money in this toy to NOT maintain it. Am I sweating a detail that really doesn’t matter or is 10w-40 the elusive unicorn set up that everyone else in the free world has evolved too? Real world input vs theoretical is what I am after. I live near Myrtle beach now and it gets hot and sticky here but still want to get to CO or UT for some generally east trail rides.

 

[cldonley]

I would go with what the camshaft manufacturer recommends. Lunati website has 1-800 tech line, maybe give 'em a shout.

 

[DirtDonk]

Is this engine going to be a little more highly strung? Are you going to drive it harder than before, when you do drive it? Heavier bronco? Big tires with perhaps taller gearing? Any reason there’s gonna be much more load on the engine that might indicate that a 40 weight would be an improvement in the protection department?

Overall I don’t think you’re gonna be truly satisfied with the real world answers. Any more than with the theoretical, that is.
That’s because there are as many stories of people running different viscosities than yours, as there are running the same.
And I bet none of them have had an oil related engine failure. or had any real notable problems from running a too-thin winter, versus a too-thick summer rating.
I’m sure there are some out there, but can they be directly tied to the oil choice? Probably very hard to say.
So from the real world, there’s no reason not to use 10W/40, any more than there is a reason to only use 10W/30.
I used 20w/50 in my 71 302 for well over 100,000 miles (total of 175k) and the engine ran as good as (actually better than) the day I bought it.
And most Bronco owners these days are probably like you. Driving less than 5000 miles a year. Probably way less!
And to double down, there’s no way I would change my engine engine oil twice a year. Even though sitting is arguably worse than daily driving.
It’s overkill and a waste of oil, in my opinion. But it’s yours to choose, and nobody can argue that you’re hurting anything by changing it more often!

Now, if you’re looking for dyno proven horsepower improvements, that’s different. But engine longevity? I don’t know that there are/is any real pertinent data on that for us.

Of course, along with all of this, I always say to make sure you have a good properly functioning PCV system.
With your choice of changing the oil twice a year though, even if you don’t drive it, I’m not sure the PCV even matters at that point. But I’ve always felt it still a good system to keep intact.

No matter what you choose, ultimately, can’t wait to hear how your long-term project comes together and runs!

 

[pcf_mark]

Regardless of viscosity (10W-30W is my go to) I would recommend Valvoline VR1 oil. It is very high quality race/off road oil with a really good additive package to help your cam survive.

 

[LUBr LuvR]

This ^^^. Started using 10W-30 VR1 years ago after coming across this info. Bit of a long read, but worth it. Especially what can happen when adding ZDDP.

https://www.sccoa.com/forums/threads/what-oil-brands-offer-the-best-protection-good-read.136304/

 

[DirtDonk]

Interesting read! Thanks for the link.
I’ve used the VR1, Amsoil Z-Rod, and the Red Line. Not always the same viscosity, but hopefully they would have similar results.
Nice to know they’re high on the list, but disappointed in the Mobile-1, which is popular and readily available. And often reasonably priced as well.

Interesting that one of them (was at the VR1?) was better in conventional than it was in synthetic. Very interesting indeed!

I didn’t check the guy’s bona fides, or test methods, but it’s nice to see a clear easy to read list.
Did it say anywhere, or link to the test methodology? If so, I didn’t note it.
Since I still have flat tappet cams, and even two new ones to break in still, it’s good to bring the subject to the fore again.
Rollers are so easy!

 

[cldonley]

Just re-read the initial post. I thought he was looking for break-in oil. My bad. Based on that article, (thanks for posting), VR1 is the obvious choice. In airplanes we often use a product called CamGuard that is supposed to cling to the cam in engines that are infrequently operated to avoid cold start damage to the cam, among other things. Wonder if there's such a product for automotive engines? When I have to crank an airplane that's been sitting, I remove spark plugs, use a start cart, and crank it til I get oil pressure. I've seen aircraft cams literally turn to shavings from sitting a long time then getting a cold start. Not good to let engines sit.

 

[pcf_mark]

This ^^^. Started using 10W-30 VR1 years ago after coming across this info. Bit of a long read, but worth it. Especially what can happen when adding ZDDP.

https://www.sccoa.com/forums/threads/what-oil-brands-offer-the-best-protection-good-read.136304/

Fantastic article! Thanks for sharing. I used to run 600 lb open spring pressure on the street and w/o VR1 and running the engine frequently I would lose roller needles. Switched to VR1 and never had a problem again. I would never run a flat tappet w/o it anymore after the flat cam horror that have been going on for years.

 

[LUBr LuvR]

Fantastic article! Thanks for sharing. I used to run 600 lb open spring pressure on the street and w/o VR1 and running the engine frequently I would lose roller needles. Switched to VR1 and never had a problem again. I would never run a flat tappet w/o it anymore after the flat cam horror that have been going on for years.

You’re welcome. It was the most concise explanation I had found, and came across is when researching ZDDP additives. Was not expecting the results they found to say the least.....

@cldonley, checked out CamGuard and there is a formula for automotive use. Wonder if that would play nice with the VR1?

https://aslcamguard.com/product/camguard-oil-additive-automotive-8oz-single-bottle/

 

[DirtDonk]

Not good to let engines sit.

That's for sure!
And why, on my only remaining long-term sitting engine with a flat-tappet cam, I'm going to pull the intake and pour oil down right on top of the cam lobes (hopefully "reactivating" the assembly lube) and prime the engine again. Before cranking.

With all the bad press about poor cam quality, I'm really looking forward to getting this one over and done with.

Paul

 

[gnsteam]

Very helpful article. Coming up to a first start up this summer.

 

[Tiko433]

Sorry if I’m derailing this thread guys …
Obviously Valvoline VR1 tops the list . How would it handle a Diesel motor ?
I have always used diesel oil for my diesel truck

 

[LUBr LuvR]

Been using Rotella T-6 in my 2006 F250 for years. Was recommended by a mechanic friend. Since the first use, the motor seemed to run smoother.

 

[LUBr LuvR]

Sorry if I’m derailing this thread guys …
Obviously Valvoline VR1 tops the list . How would it handle a Diesel motor ?
I have always used diesel oil for my diesel truck

Well, since the topic is oil viscosity, and many of us use our trucks for hauling Broncos and other reasons….sounds like fair game.

Been using Rotella T-6 in my 2006 F250 for years. Was recommended by a mechanic friend. Since the first use, the motor seemed to run smoother. Yeah, it’s a bit pricy for the 4 jugs it takes (w 1 qt left over), but so is rebuilding a diesel engine.

Be interesting to hear what others are using.

 

[cldonley]

You’re welcome. It was the most concise explanation I had found, and came across is when researching ZDDP additives. Was not expecting the results they found to say the least.....

@cldonley, checked out CamGuard and there is a formula for automotive use. Wonder if that would play nice with the VR1?

https://aslcamguard.com/product/camguard-oil-additive-automotive-8oz-single-bottle/

That's a cool find. Gotta check into that!