I was just wondering what oil you all thought would work good in my newly rebuilt 390FE. It's got a Crane hydraulic cam, not roller though, forged pistons, ~10 to 1 compression, and the bearing clearances were slightly toward the looser side of the factory range. Doesn't leak 1 drop.

Right now I'm using Mystik JT-8 10w30, diesel rated. Is this fine or should I go heavier next change? I do notice a little piston slap when it's cold, because of the forged pistons, which run a little more cylinder wall clearance.

I'm thinking I'll probably stay with the 10w30 unless someone says something incredibly bad will happen.

 

Sounds fine. Not synthetic, not too light for that design. =)

On a side note Rusty, you been to the Iowa chapter forum? We're planning a meet for the 19th, and I think it'd be pretty cool if you could make it. We've got 3 people making it from your area already (Nogo73, Truckertaz, and lifted78).

What's the 390 in? What's its hp/tq?

 

We'll have to see. I'll swing by the Iowa forum and see where it is, I dont want to drive too far on this new engine.

The 390 is in my '70 F100. DD2k says 389hp @ 5500rpm, and 441ft-lbs @ 3500rpm. I can tell you it's a blast to drive it.

 

I'm wondering Rusty, does anyone really have even one chance in a million of pursuading you to use something other than a diesel-rated oil?

 

Why would you want to?

 

Flash could probly give the best answer if he is listening, but I would think 10w30 is a good break in weight especially with the cool temps. If clearences are on the loose side I would stay with a diesel 15w40 in the warm months and the 10w30 in the cool ones.
Just my 2cents
Dan

 

15w40 rotella

 

Hey rusty, what are your main and rod bearing clearneces? Im running a hair over .0015 on my mains and rods. Also, whats your oil pressure? Did you do the oil mods to your block?

 

Cold my oil pressure is 75 - 80 psi, depending on rpm. Hot, idle is 10psi, anything above idle is 50 - 75psi, depending on rpm. Clearances range from .0010" to .002" on the mains, and the rods are all around .002". Yes, they're a little loose, but so far no problems. The above pressures are with Mystik JT-8 10w30, diesel rated. Its winter and I dont feel like going any thicker. I need this thing to crank over! Summer I will be running 15w40.

The only oiling mod I did was to restrict oil to the rockers with a #90 holley jet. Oh yeah, and I used a high volume oil pump. All the block passages are stock.

 

Rusty, the Mystic you are running is about as good as you are going to find for your FE. You are going to have be aware that a lot of the dual rated oils are going to disappear when the SM rated oils take over. I doubt that the Mystic will make the transition but as long as they don't change formualtion you should be fine but it won't be an SM oil. When I rebuild my FE this spring, I will most likely be running a combination of Delo 400 CI-4+ and Redline in 10w-30. The Delo has a decent add pack and the Redline for the extra moly. The old FEs are going to be starving for an add package as the SM oils come online. Might want to let your friends that have know they most likely are going to have to blend their own oils. An SM oil with Redline or Amsoil as an additive should work as both of these have a generous add pack. I would suggest 2 qts of either for the additives. You might also want to check some of the auto parts stores for old oil still sitting on the shelf. I found some SJ the other day in a Pep Boys. Just shake it occasionally and it should be fine.

 

Do I sense a little bit of humor there?

I dont think my supply of Mystik will dry up anytime soon. If it does, I'll look into your suggestions. I'd really like to keep it all one thing in the crankcase, if that makes any sense.

I wonder if the oil companies are going to come out with an "Older / Vintage Engine Formula" for older engines like these FE's, with the older API ratings? We already have high mileage oil, but how will SM affect that?

 

SM oils are going to have less ZDDP and Phos which are anti-wear agents. The old engines rely heavily on the add pack as that was the norm when they were made. The high mileage oils, the only difference between them and regular oil is the actual viscosity is on the thick end of the scale and they will have some form of seal swell agent to stop leaks. The HM oils are not going to be of any benefit to the FE as long as they are rated SM. I just changed my 04, 4.6 that had 5000 miles on an SM oil and I am not happy. Wear metals went up so I am running it again to see if that was washout or real. I should know for sure around the end of January or first part of Feb. I will post the data sheet when I get it.

 

Rather than mixing oils, would it be better to use an additive. Flash, you have stated that Valvoline synpower oil treatment has a lot of moly in it. Would adding that do the same thing? Also, is moly going to have the same protection as zinc on the valvetrain? There is also STP, but that is so thick; it probably does nothing but raise the viscosity. I ask this because I have a fresh rebuilt '71 302 with a moderate cam in my mustang and want to have good protection in it. Maybe I better get to Fleet Farm and buy a few jugs of Mystik and be ok for a while. The only problem with that is my F150 4.9L I like 5w30 in the winter. It is going to be around -5 F tonight. 10w30 seems to thick in winter.

 

cmlind, the Valvoline Synpower Oil Treatment could be an alternative. The make up looks something like this:
Moly 3500
Boron 1400
Calcium 1700
Magnesium 2700
Phos. 2100
Zinc 2600

Those are ballpark round numbers in PPMs or Parts Per Million. I would not suggest a full bottle per oil change. The carrier fluid has the viscosity rating of 190 SUS@210F which means it's pretty thick and will alter the original oil viscosity. It also uses a carrier fluid that will breakdown under extreme pressure and high heat which can result in the formation of sludge. I would suggest not using more than 1 oz per quart of oil and a maximum of 1/3 of the bottle. In the case of additives, more is not necessarily better and can be counter- productive. As with all of the oils of today and in the last 25 years, the blending of add packs and basestocks has been a fine balancing act.

 

Flash, why are the SM oils going backwards?

I have been using Mobil1 10w30 in my 99 V6 5speed because I thought that the syn. oil would give me aded protection against the crank hitting the bearings when the motor is lugged (backing a trailer in tight areas). Should I look at a different oil?

Thanks for your great information posted on this site.
Dan