44 year oil QS 10w40, 4.5 years 1811 mi, 1973 240Z

[PimTac]

This has been a great thread down memory lane for me. I remember when Datsun announced the Z car. It was oohs and aahs all over the high school campus then. Just seeing one on the street made hundreds of heads turn.

I may have missed it but are you going to a regular oci now? I would think every two years would work well.

 

[jayg]

Originally Posted By: krismoriah72


However i gotta say that if i were you i would probably try to sell them on ebay to collectors. The oils you have are worth more as a historical reminder and artwork than lubrication. I can see that oil in the trunk of a 1970s car at a car show gathering all kinds of chit chat.

Kudos to you man.


I've had some for sale on here before years ago and besides a few exceptions, it was a giant waste of time. Most people wanted 1 can for $5 shipped to put in their garage. I think 6 pack for $60 plus shipping is VERY fair and more worth my time as I have hundreds of these cans but not as much time to deal with the tire kickers. After a few dozens sales, I decided to use it, test it, and enjoy it for myself rather than deal with broke people who want something for nothing.

Originally Posted By: PimTac
This has been a great thread down memory lane for me. I remember when Datsun announced the Z car. It was oohs and aahs all over the high school campus then. Just seeing one on the street made hundreds of heads turn.

I may have missed it but are you going to a regular oci now? I would think every two years would work well.


Yeah I'm probably going to drop it to 2-3 years regardless of miles since it just doesn't get the miles put on it from a daily commuter. I keep it in the lower 48 and only get to drive it sparingly when I'm in state.

Originally Posted By: SR5
Jayg, thank you for doing this, very interesting.

So 1970's 10w40 had about ~1200 ppm zinc and a Ca detergent package. Good to know.

BTW that picture of all the old oil stacked up looks great.


Well, we can't say all 1970's 10w40 had that but it appears that QS did in detergent oils. Phosphorus too.

Originally Posted By: redbone3
Or, the oil was fine and you had a small leak of coolant getting into the oil.


I'm still interested why you suspect I had coolant leaking in to the oil when zero antifreeze was found and Sodium looks pretty marginal.

 

[bigj_16]

How old is that C16? I use to run that in a ratio of three gallons 91 unleaded to one gallon C16 in my Buell.

 

[redbone3]

I was replying on a coolant leak to this post.



Originally Posted By: tig1
The QS in the caused terrible sludge in my 1964 Valiant. I did 2K OCIs at the time, but after 50K the engine was full of sludge.

 

[DuckRyder]

BTW, are you running 44 year old oil filters too, and are you going to cut that open for our edification? Or would that be too BITOGer like.

Now, since it was below freezing this morning I have to go put 0/20 in my old truck... back later...

 

[jayg]

Originally Posted By: DuckRyder
BTW, are you running 44 year old oil filters too, and are you going to cut that open for our edification? Or would that be too BITOGer like.

Now, since it was below freezing this morning I have to go put 0/20 in my old truck... back later...

Nope just circa 2013 STP spin on. It’s funny that it’s been winter in Atlanta sort of this year. That’s where the z is and I drove it during that snow a little last week.



The C16 wasn’t THAT old but remember this is over 4.5 years and I had other performance cars at the time so it made sense to share it. The last few fill ups have been with pump gas only though with stabil in the tank. If that’s not enough for ethanol issues and I have carb problems or rubber lines swelling, I might go back to the c16.

 

[littleant]

Thank you for the photo of the old oil. Brings back fond memories.

 

[DuckRyder]

Originally Posted By: jayg
... It’s funny that it’s been winter in Atlanta sort of this year. That’s where the z is and I drove it during that snow a little last week. ...


It has sort of been winter. I was in TN during the snow but when I came back Monday it was still on the ground. 24 this morning and supposed to hit mid 60’s later is the week..

This whole post is a blast from the past, I used to get some oil in cans when i was in my teens and early 20’s though some stuff had gone to plastic bottles (pretty sure my then favorite Castol GTX was in bottles by then). I had at one point during that time a 240Z, it was a rust bucket but man was it a blast to drive. I used to head over to Z-Car Corner in Douglasville (I talked to someone a few weeks ago that says it is still there) and in he was telling me that it was one of the very first cars built (like first 250 or first 500 or something) because of the way the hatches opened behind the seat. It is a car I wish I had had the means and wherewithal to keep and tuck away for a later time when I could restore it properly. I also had a 280Z (also a rust bucket) that was used for an autocross car.

Anyway... Thanks for the post and interesting UOA.

 

[fdcg27]

The oil itself looks pretty good.
It didn't shear out of grade nor did it oxidize and TBN remains strong.
How hard was it to break the engine free?
That it needed to be broken free would indicate that the rings were rusted to the bores. That it survived this and still exhibits no observed oil consumption is a tribute to the quality of the parts Datsun used in building these things since you apparently broke no rings in breaking it free.
This engine must have had extensive internal corrosion when you brought it back to life and the metals levels in this UOA probably reflect that more than wear. With all of that free vintage oil, a couple of short drains after getting this old Z running would have been a good idea, but I'll bet that your next UOA will show much lower metals than this one did. These engines are known to be capable of well over 200K, so a little TLC in drain intervals would not be misplaced since the one you have appears to be healthy.
Fuel isn't bad. I saw higher fuel in a UOA from my old 318i, despite FI with stock tune.

 

[jayg]

The rings weren’t that stuck but I suspected the valvetrain was. A valve adjust, broke the engine free by hand with a breaker , another valve adjustment hot and it’s been good for almost 5 years.

I’m very familiar with these cars as I’ve had several over the years. Restored, one was V8 swapped, etc. I’ve done plenty of internal engine work and tear downs on old Datsuns and actual fast nice cars too. I understand the metallurgy and the implications of what each metal could possibly mean in my UOA.

That fact that I have had so much fun with a vehicle I have so little money in is my favorite part of this experiment. I’m not trying to make it live forever but even if I was, I don’t think a modern oil would do better in the use I give it anyway and that’s the only reason I’m sharing this.

 

[jayg]

I'll add this too because I think some of you aren't getting the same takeaways from this as I did.

It's commonly repeated on here that oil "goes bad". It didn't in my case.

"The 70's multigrades sheared down immediately and to a terrible degree" -Mine didn't shear out of grade and I subjected it to nearly 7000 rpms regularly.

Did you know what the additive pack looked like in QS from the 70's? Nope and neither did I. I'll use it and find out.

Did you know what the TBN of a QS 10w40 from 1973 would be after 4.5 years and 1811 miles of hard use before I posted this thread? No you didn't and neither did I. That's why I did this experiment was to learn and see for myself some of the things that get repeated ad naseum by folks that don't have first hand experience with it.



For the folks that look at the wear numbers and just comment "That looks horrible" or "I had a Valiant that sludged up with that stuff". Did you look at the same UOA I did?

Did you learn anything from this? I know I did.

But there are wear metals....well no [censored] there are wear metals. It for 24 years in a non-climate controlled environment then I woke it up and drove it hard for 4.5 years. There would be wear metals in ANY oil I would have put. That's NOT the lesson here. Look at the other pieces of information we can take away from this.

 

[addyguy]

I'm surprised there isn't more Mg detergent in the add-pack - 1970's oils almost always used higher Mg than Ca in the detergent pack.

Thanks for sharing - I agree that any UOA in this scenario would look 'bad' by our standards.

Looking forward to the UOA on the Valvoline!

 

[KL31]

Thanks for sharing. I also don't get the tunnel visions comments. Engine was broken free, sat for so many years, uses leaded fuel, was driven like it should be etc.

UOA makes sense. Old oil is still fine, it's just the other things that bumped some numbers up. I'm assuming you need to use some sort of lead additive in the fuel as leaded fuel is no longer available?

 

[DuckRyder]

Originally Posted By: KL31
... Old oil is still fine, it’s just the other things that bumped some numbers up. ...


Maybe, Maybe even probably.

But we don’t KNOW that. Could be bad oil and no problem from the other stuff. Could be a combination.

 

[jayg]

Originally Posted By: KL31
Thanks for sharing. I also don't get the tunnel visions comments. Engine was broken free, sat for so many years, uses leaded fuel, was driven like it should be etc.

UOA makes sense. Old oil is still fine, it's just the other things that bumped some numbers up. I'm assuming you need to use some sort of lead additive in the fuel as leaded fuel is no longer available?



No I used actual leaded race fuel. It’s still widely available just not at the pump.A lead substitute additive is a much weaker mix that probably wouldn’t have even bumped the lead count up on the UOA.

 

[Patman]

While I totally appreciate the unique UOA here, it would also be good to see this old oil used on a newer car without any "issues" such as the leaded fuel and the hard racing

 

[jayg]

Originally Posted By: Patman
While I totally appreciate the unique UOA here, it would also be good to see this old oil used on a newer car without any "issues" such as the leaded fuel and the hard racing



I wouldn't run this old oil on any modern vehicle at all. I get what you are saying that we would get a more accurate picture of how the oil performed on a vehicle with tame street use and regular unleaded fuel but then again I wouldn't advise anybody run this in modern emissions controlled vehicles anyway. The L24 isn't smart enough to know better.

The next UOA will probably be more tame driving and less leaded fuel anyway and give different numbers. It's still a couple of years off anyway. In the meantime, I'll keep using super old conventional in this thing worry free.

 

[DuckRyder]

I was thinking long the same lines this morning, but realized “newer car” wasn’t the right term.

I think something with a more extensive track record is probably what I’d like to see...

 

[jayg]

Originally Posted By: DuckRyder
I was thinking long the same lines this morning, but realized “newer car” wasn’t the right term.

I think something with a more extensive track record is probably what I’d like to see...


Agreed, but it is what it is. I've still gotten many years and smiles out of this thing without it blowing up. Eventually I suppose I'll have that track record to see how metals progress but it will just take quite a while and that is a great thing. Oil pressure is great and no abnormal noises,burning or smoking.

Some folks on here have unrelated problems they are trying to magically solve with oil choice on their brand new cars and others like myself are interested in completely different aspects of the oil world.

 

[loneryder]

Don't thrash that car. It's a classic with no rust. I remember when they came out. Such demand that you couldn't get them. But they rusted out badly. You have something there that a lot of people would want.