What oil for 1968 Mopar?

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Just buy a motor oil with lots of ZDDP already blended and avoid the additives.

AMSOIL Synthetic 10W-30/SAE 30 Diesel Oil (ACD)... Lots of ZDDP, shear resistant, made with quality PAO synthetic base oils, and not as pricy as the Amsoil 10W-30 Dominator Racing Oil.

Also, try a 30 grade motor oil first. People like to go overboard with 40 and 50 grade oils in the older muscle cars. Usually don’t need them unless you’re racing a lot and generating lots of heat. Remember, you only need 10psi of oil pressure per 1000rpm.

I've got a 1969 Plymouth Road Runner myself... Gotta love the Mopars!
 
Originally Posted By: NHHEMI
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Well, I have run 20W-50 in the following MOPAR engines from 65-76 wiith no issues...

318
340( actually my brother ran it in his 3 Darts - I never had a 340 )
360
383
440


Well, you can't really kill a Mopar with your choice of oil :-D

But the times I've tried 20w50, they just didn't respond well. Noise went up, oil *consumption* went up, and even though I only tried it on pretty tired engines, blow-by accumulation in the air cleaner went *up*. In other words, it did just the opposite of what I wanted to do with a heavier oil. Plus there's the 430,000 miles my 318 ran on 10w30 and nothing else. Just my experience

By the way- I've got a Royal Purple experiment going on. My "new" (30,000 miles since rebuild) 1966 440 is running RP 0w40 for this next interval (but the numbers-matching, never rebuilt 440 in the '69 Coronet R/T still gets Rotella 5w40!) Engine noises are a little quieter in the '66 than on Rotella 5w40, believe it or not (this engine has loose-ish HE pistons and a good bit of piston slap when cold). Oil pressure is great, although it still spikes over 90 psi if I get the revs up too much before its warmed up a little. It settles down to 80 PSI cruising and 40 psi at idle when fully hot. Probably didn't really need to build this engine with an HV oil pump, may even pull it for a standard pump at some point.

Obviously I'm not scared of the SM rating for the '66. The cam's fully broken in and will be fine. Its just the Magnum/Roadrunner repro cam, not anything really aggressive with monster spring pressures.
 
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Originally Posted By: 440Magnum
Originally Posted By: NHHEMI
\

Well, I have run 20W-50 in the following MOPAR engines from 65-76 wiith no issues...

318
340( actually my brother ran it in his 3 Darts - I never had a 340 )
360
383
440


Well, you can't really kill a Mopar with your choice of oil :-D

But the times I've tried 20w50, they just didn't respond well. Noise went up, oil *consumption* went up, and even though I only tried it on pretty tired engines, blow-by accumulation in the air cleaner went *up*. In other words, it did just the opposite of what I wanted to do with a heavier oil. Plus there's the 430,000 miles my 318 ran on 10w30 and nothing else. Just my experience

By the way- I've got a Royal Purple experiment going on. My "new" (30,000 miles since rebuild) 1966 440 is running RP 0w40 for this next interval (but the numbers-matching, never rebuilt 440 in the '69 Coronet R/T still gets Rotella 5w40!) Engine noises are a little quieter in the '66 than on Rotella 5w40, believe it or not (this engine has loose-ish HE pistons and a good bit of piston slap when cold). Oil pressure is great, although it still spikes over 90 psi if I get the revs up too much before its warmed up a little. It settles down to 80 PSI cruising and 40 psi at idle when fully hot. Probably didn't really need to build this engine with an HV oil pump, may even pull it for a standard pump at some point.

Obviously I'm not scared of the SM rating for the '66. The cam's fully broken in and will be fine. Its just the Magnum/Roadrunner repro cam, not anything really aggressive with monster spring pressures.


I always ran the 20W-50 from early July through early September during the hottest part of the year. I did a lot of drag racing with most of the engines too. Never had noise or consumption issues. I ran 10W-40 the rest of the year when the vehicles saw the road.

You know, you kill me on here with all of your MOPAR stories!
crazy2.gif
Been a long time since I had an old MOPAR muscle car. I miss those days!
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At least my Ram has the HEMI and I can play with that ssome.
 
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Had a 67 Monaco in H.S. w/383ci and afterward, a 73 NewPort Custom w/400ci and both used anything 10W40 then. I would think that the same would be true today. Dad had Mopars most of his life and I beleive he did the same. All of the advice above sounds good to me.
 
One thing people tend to forget is that 20w20 was factory fill in all Chrysler engines (except maybe the 426 Hemi and 426 wedge) right up until the early 60s when they switched to 10w30.

Unless you've rebuilt the engine and put a hotter than stock cam in it, I would think any modern 10w30 would provide more than adequate lubrication, and one of the "high mileage" type oils would be the best choice.
 
Below are the motor oil recommendations copied out of the 1969 Plymouth Service Manual. 50 grade motor oils are not recommended even in the production 426 Hemi, at least in 1969.

In the case of all factory production Mopar engines in 1969, there are a couple areas where I could see justifying the use of a 50 grade motor oil – where bearing clearances are modified greater than factory specs, or for sustained high temperature use in endurance racing. In a healthy street or street/strip Mopar why add the extra drag to the engines reciprocating assembly with 50 grade oil?

*** 1969 Plymouth Service Manual ***

Oil Viscosity Recommendations (All engines except 426 Hemi)

Multigrades

SAE 20W-40 or SAE 10W-40 -
Where temperatures are consistently above + 32F

-OR-

SAE 10W-30 or SAE 10W40 -
Suitable for year long operation in many parts of the U.S.; may be used where temperatures occasionally drop as low as -10F.

-OR-

SAE 5W-30 or SAE 5W-20 -
Recommended where minimum temperatures are consistently below +10F.

Single Grades

SAE 30 -
Where temperatures are consistently above +32F.

SAE 10W –
Where temperatures range between + 32F and -10F

Oil Viscosity Recommendations (426 Hemi Engines)

Multigrades

SAE 20W-40 -
Where temperatures are consistently above + 32F

SAE 10W-30 or SAE 10W40 –
Where temperatures are consistently below +32F.

Single Grades

SAE 30 or SAE 40 -
Where temperatures are consistently above +32.
 
A lot of my engines were modified and they were driven HARD! At the time 20W-50 was what my circle of people used. We all ran it in our hi-perf vehicles. I/we never had problems with it. I did run 10W-40 if the vehicles saw the road other than those 3 months in the midddle of summer. A lot of my cars were only out from May-Sept.
 
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