Oil for 1985 Nissan Pickup. Is high ZDDP required?

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Getting read to change oil on a 1985 Nissan Pickup (2.4, automatic) with 99K miles. I have some conventional Pennzoil High Mileage 10w-30 that has been sitting in the garage for around 3 years or so. I was going to use that and a Fram Tough Guard (what Walmart had).

Googling around the internet I see some people saying that an older flat tappet engine like this should have an oil higher in ZDDP. And, there's no better place on the internet than here to ask an oil-related questions.
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Is the Pennzoil High Mileage 10w-30 fine? I definitely want to keep the truck for many years, so if it's not I'd certainly be willing to go buy something else.

And, out of curiosity, oil sitting for 3 years in a bottle should still be good, right?

Thanks.
 
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KA24E.

Use that three year old oil on that 34 year old Datsun/Nissan and enjoy it.

Back To The Future truck was a Toyota 4x4. Similar but different look than yours.
 
I'm sure that oil is fine. I think that engine is a SOHC and therefore not really a flat tappet design. I owned one back then and going by memory about the SOHC thing.

By the way, mine lasted a very long time and the subsequent owner had a couple hundred thousand miles on it.

But like all engines with a timing chain, it's good to use a quality oil and change it frequently.
 
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Originally Posted by 92saturnsl2
Nissan pickup engines were all OHC, so no flat tappet concerns with these engines.



So maybe not flat tappet, but if a flat rocker acts on a cam, is that not the same thing?
 
Originally Posted by Hal9000
Getting read to change oil on a 1985 Nissan Pickup (2.4, automatic) with 99K miles. I have some conventional Pennzoil High Mileage 10w-30 that has been sitting in the garage for around 3 years or so. I was going to use that and a Fram Tough Guard (what Walmart had).

Googling around the internet I see some people saying that an older flat tappet engine like this should have an oil higher in ZDDP. And, there's no better place on the internet than here to ask an oil-related questions.
smile.gif


Is the Pennzoil High Mileage 10w-30 fine? I definitely want to keep the truck for many years, so if it's not I'd certainly be willing to go buy something else.

And, out of curiosity, oil sitting for 3 years in a bottle should still be good, right?

Thanks.

No, you do not need higher ZDDP for flat tappets with today's modern oils.

However, you do need a thicker base oil for flat tappets. The viscosity your valvetrain experiences is the base-oil viscosity at the given oil temperature because of the ultrahigh shear rates in the valvetrain, not the kinematic or HTHS viscosities. A 15W-40 HDEO is by far the best choice, especially in your climate. The base oil will not get much thicker than that.

10W-30, especially a high-mileage one or an HDEO 10W-30 is OK if your climate does not allow a 15W-40. There is no HTHS viscosity data on Pennzoil HM 10W-30 but it's probably around 3.4 cP and the base oil should be moderately thick as well, although not nearly as thick as that of a 15W-40.

Avoid 5W-30, as the base oil will be too thin for flat tappets. Valvoline Advanced Synthetic 5W-30 could be an exception.

Oils have at least five or more years of shelf life. Shake the bottle before use.

If anyone asks the flat-tappet question again, the answer is any modern 15W-40 HDEO and the ZDDP level does not matter.

There is also Amsoil ACD 10W-30/SAE 30, which is perfect for flat tappets, as it has a very thick base oil because it is a monograde, but it's expensive.
 
Originally Posted by dave1251
Pennzoil HM is a good fit for your truck enjoy!



I agree with dave1251... Pennzoil HM.
 
SOHC doesn't mean it's not flat tappet.... i haveppen to have a SOHC flat tappet engine in my Escort.

The camshaft is in the head, and the hydraulic flat tappet lifters ride on the cam, which push up directly on the rocker.
 
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Originally Posted by Cujet
I'm sure that oil is fine. I think that engine is a SOHC and therefore not really a flat tappet design. I owned one back then and going by memory about the SOHC thing.

By the way, mine lasted a very long time and the subsequent owner had a couple hundred thousand miles on it.

But like all engines with a timing chain, it's good to use a quality oil and change it frequently.


There are various designs of SOHC valvetrains, some do actually have lifters like the ones you would find in a pushrod engine.
 
Originally Posted by Hal9000

And, out of curiosity, oil sitting for 3 years in a bottle should still be good, right?


Yes, I still have oil in the bottle left over from the 1990's - it's perfectly fine and never goes bad if stored properly.
 
KA24E - that's the head and cam used for seq. IVA valvetrain wear tests.

It's like a Honda Civic SOHC design without the VTEC.

Remember too High ZDDP = Cam and follower wear.
 
Thank you for all the responses thus far. Here are a few pics of the vehicle.

She's an ideal runabout/Home Depot vehicle. These older trucks that are low to the ground are so easy to load/unload. It's also extremely easy to park, and has power steering even. Now, obviously it's not going to pull a huge trailer or boat, and with the three speed automatic it isn't going to win the Cannonball Run. It's the 'Sport Truck' trim level, which I presume got you bucket seats in blue plaid and a snazzy ST decal. However, it apparently didn't include AC.

[Linked Image]


[Linked Image]
 
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Does this truck have the engine with two spark plugs per cylinder?

I almost bought a Datsun 4x4 with that motor. Really nice truck. I wish I had.
 
Originally Posted by FordCapriDriver
SOHC doesn't mean it's not flat tappet.... i haveppen to have a SOHC flat tappet engine in my Escort.

The camshaft is in the head, and the hydraulic flat tappet lifters ride on the cam, which push up directly on the rocker.


Correct, those are flat tappet engines. Always liked the design. For a 2 valve engine, they seemed to run really well when properly tuned too.
 
Is that the KA24 ?

If so, you've got good reason...

https://www.swri.org/sites/default/files/sequence-iva-test.pdf

The KA24 was the engine chosen for the sequence IVA camshaft wear (warmup) test because it's wear could be accelerated and predictable.

bobbydavro, an oil formulator who used to post here (worked on Edge) said that Castrol had a target of 30% of the allowable in the test. Most of the majors seem to have similar targets .

So the good news is that every oil on the shelf has been designed specifically to protect YOUR engine..(if it's the KA24)
 
Originally Posted by ARCOgraphite

Remember too High ZDDP = Cam and follower wear.


I heard this but never seen any real evidence to support it, M1 V-Twin has 1750 ppm Zinc while penrite HPR 30 has 1530 ppm zinc, and both have been heavily used for many years without issue.


Originally Posted by Gokhan


No, you do not need higher ZDDP for flat tappets with today's modern oils.

However, you do need a thicker base oil for flat tappets.....

Oils have at least five or more years of shelf life. Shake the bottle before use.

If anyone asks the flat-tappet question again, the answer is any modern 15W-40 HDEO and the ZDDP level does not matter.
.

OP, this is the most recent pet theory from Gokhan, if you asked him a year ago he was all TGMO 0W20 and a year before that it was all M1 0W40 with PAO & Ester and tri- nuclear moly. Still a HDEO 10W30 or 15W40 is good advice.

I think Shannow hit the nail on the head and any modern oil should work for you, and give the vehicles age it has probably seen a few different oils already. I think your conventional Pennzoil High Mileage 10w-30 will be fine.
 
So much for the flat tappet.

It appears to be Z24, which has a standard overhead-camshaft valvetrain with sliding rocker arms. It's not flat-tappet.

Therefore, any modern oil from 0W-20 to 25W-60 would work in this engine. Dictate the oil choice by the oil consumption. It probably consumes oil and 15W-40 would be a good choice in California to control the oil consumption.
 
Originally Posted by SR5
[I heard this but never seen any real evidence to support it, M1 V-Twin has 1750 ppm Zinc while penrite HPR 30 has 1530 ppm zinc, and both have been heavily used for many years without issue.


Penrite V Twin 20-50 has 1800...currently back in my Airhead after a year on 30.

It's not so much flat tappet, as 2 valve. 2 valve engines put much more load on a valve train than 4 valve.
 
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