72 Plymouth Duster with a 318. Need oil advice!

[Arnoldr45]

Originally Posted By: 440Magnum
FWIW... as a long-time Mopar guy, I really don't think there's a sound reason for using 15wXX HDEO oils for a 318.

NO, it absolutely WON'T hurt. But all its going to do is slow oil flow on startup, jack the oil pressure up silly-high, put some (probably not measurable) extra wear on the oil pump drive, and make the lifters tick longer on startup (if they tick, not all do). Go ahead if you want to, but it just isn't needed. It sure isn't worse in that regard than the old straight 30 weights back in the day and these engines did fine on them. But in today's world of very high VI oils (even budget oils)... for anything in the continental US, a good 10w40 or 5w40 is absolutely the thickest thing that engine needs. And if cost isn't an option, 0w40 is just about ideal.



Alright I'll look into the 0w40 than, I'm really a fan of using the best. My dad wasn't and his vehicles really paid for it, it seems it costs a lot more in the long run.

edit: or 15w40 lol you guys

 

[440Magnum]

Originally Posted By: Arnoldr45
Originally Posted By: 440Magnum
FWIW... as a long-time Mopar guy, I really don't think there's a sound reason for using 15wXX HDEO oils for a 318.

NO, it absolutely WON'T hurt. But all its going to do is slow oil flow on startup, jack the oil pressure up silly-high, put some (probably not measurable) extra wear on the oil pump drive, and make the lifters tick longer on startup (if they tick, not all do). Go ahead if you want to, but it just isn't needed. It sure isn't worse in that regard than the old straight 30 weights back in the day and these engines did fine on them. But in today's world of very high VI oils (even budget oils)... for anything in the continental US, a good 10w40 or 5w40 is absolutely the thickest thing that engine needs. And if cost isn't an option, 0w40 is just about ideal.



Alright I'll look into the 0w40 than, I'm really a fan of using the best. My dad wasn't and his vehicles really paid for it, it seems it costs a lot more in the long run.

edit: or 15w40 lol you guys

Don't sweat it too much... for a 318 I'd say oil quality is more important than grade (within limits of course).

And I'll warn you that M1 0w40 can be hard to find. Around here its easier to find RP 0w40 than M1 0w40 on store shelves...

 

[Rock_Hudstone]

Originally Posted By: Arnoldr45
I've heard from various people that adding an additive to oil messes up the levels of the oil and in effect degrading it since it's no longer a fine balance done by the manufacturer, any truth to that?

Yes, there is such a thing as too much ZDDP. That why its better to stick with a manufacturer formulated additive like GM E.O.S. which is about 6000ppm zinc along with a high dose of calcium.

Whereas, aftermarket additives like ZDDP-plus are something on the order of 30,000 ppm zinc.

 

[Rock_Hudstone]

Originally Posted By: Arnoldr45
Alright I'll look into the 0w40 than, I'm really a fan of using the best. My dad wasn't and his vehicles really paid for it, it seems it costs a lot more in the long run.

edit: or 15w40 lol you guys

0w-40 or 5w-40 is overkill on a 318 stocker in the Arizona climate.

If you want something a step up from conventional 15w-40 use the Rotella semi-syn 10w-30 at Walmart.

 

[dakota99]

So do the newer 318's (1990-2000) have a nylon timing gear as well? Or did they change this later on?

Strangely curious now.

 

[NHHEMI]

Originally Posted By: 440Magnum
FWIW... as a long-time Mopar guy, I really don't think there's a sound reason for using 15wXX or 20wXX oils for a 318. (sorry, NHHEMI, we usually agree on stuff like that)

It's ok. No one agrees on everything all the time. I too am a long time MOPAR guy and I ran my A & F bodies HARD. I ran 10W40 and 20W50 regularly in them and the results were very good. Seeing as the OP is in AZ he can see temps of 110-120 often in the summer. A 20W50 is not going to be an issue then at all.

 

[Kuato]

Our family had several Mopars of that vintage, many with the 318, and I recall that 10w40 was the original spec.

In AZ it's probably hot enough to run the 10w all year long. You could also go with 5w40 or even 0w40. If you go with synthetic, be sure to use an oil that has a good amount of ZDDP, as those years did not have roller cams.


And +1 on the timing chain. We used to replace ours about every 70k along with the alternator. A modern timing chain will likely be better than original, and last longer.

 

[440Magnum]

Originally Posted By: dakota99
So do the newer 318's (1990-2000) have a nylon timing gear as well? Or did they change this later on?

Strangely curious now.


No, the Magnum 5.2 and 5.9 have a steel gear (not a roller though). My father put ~250k on one of those without ever opening it up. In fact, I think they ditched the nylon gear a long time before that, maybe by 1980? I'm pretty sure Dad's 83 M-body didn't have a nylon gear, because he put over 200k on it also.

 

[SS1970chrysler]

My '86 5th Avenue still had nylon gear.

 

[440Magnum]

Originally Posted By: SS1970chrysler
My '86 5th Avenue still had nylon gear.


Could have been, I've never had one of that era apart. I've heard that some engines used a nylon coated metal gear. The nylon could still wear away and shed chips that could potentially restrict the oil pickup strainer, but the metal would prevent it from actually jumping out of time.

Kinda makes you wonder about the nylon padded tensioners in modern engines... except the type of stress is a bit different. Still, theres lots of sliding across that nylon facing...

 

[ranger99]

Growing up I had a 78 Newport with a 400, my brother had a 72 Newport 440, 10-30 in both, and in all the chrysler small and big blocks that friends and family had. I personally don't see where a 40 weight is necessary for your car. 10-30 is a great blend that would suit you well. Pennzoil would be my first choice for that car, they have a bit of ZDDP.

 

[motorguy222]

SN oils that have the API certification Donut are limited in the amount of zinc they can have in them.Oils used to have 1000-1200 ppm of zinc in basic oils,that is no longer allowed if an oil is API SN certified.

Pennzoil and any other API SN Certified oil has less zinc than they used to have,most oils now have around 800 +/- ppm
of zinc.Some have gotten to the 770 range.

Phosphorus is also limited to 800 ppm in API Certified oils.

Some companies are now using titanium as an additive to make up for less zinc.Mobil,Conoco-Phillips/Kendall and Castrol are using titanium in some or all of their oils.

 

[Norm Olt]

Personally I'd go with an HDEO but there are a lot of deals on less than $10 for 5 QTs. "conventional" + filter out there.

Changing the oil & filter a couple times should get you a pretty good idea as to how this engine will use oil. Based upon your description (80K miles?) it ought to be good for another 40 years, or so...

A 3-speed automatic, I presume?

Just change out all the fluids, and drive it and enjoy, although the timing gear info seems relevant.

Cheers!

 

[ted s]

any 15w40 has more tham enough zddp for a stock 318 valve spring

 

[440Magnum]

Originally Posted By: ted s
any 15w40 has more tham enough zddp for a stock 318 valve spring


So does any brand-name SN 10w30. Really. All the hoopla about SM and SN oils not having enough for any flat-tappet engine is just wrong. For a plain vanilla engine like a Mopar 318, Ford 302, or Chevy 350 (not hi-po versions) that has already been broken in, then its just fine.