Classic cars classic oils?

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So iv seen many sites selling whats called classic car oil. Usually its 20w50.
If you own an older car made in the 1960s does that mean you have to use oil technology from that period?
 
Alot of cars from the '60's used 10w40 wt. Today's oils are worlds better then what was available then. The only thing to watch for is oils that can cause excessive cam lobe wear. I forget which ingredient you want it to be high in, I'm thinking moly. A motorcycle rated oil might cover that issue.,,,
 
Originally Posted by slybunda
If you own an older car made in the 1960s does that mean you have to use oil technology from that period?

no.

Most oils are backward compatible. Meaning you can use newer oil on older machines.
That being said, there's a few additives you can purchase for older engines which benefit from anti-wear additives such as Moly or Zinc that are not required for newer engines.
Most anti-wear additives are found in many diesel motor oils, Rotella T4 being one of them.
Downside to diesel oils is they tend to have a detergent package that some believe is too harsh on gasoline engines.
 
Engines of 50s era had larger tolerances. For that reason alone, I'd use 20w50 or at least a 10w30 or a 30 or 40w HD. Checking the oil at every fillup was a good practice in those days
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I have several late 40's flat heads and run 10w-30 HDEO in them. Most are dual rated (CK-4, SN).

If you have a worn engine with low oil pressure would be the only reason to jump up to heavier oil.
 
Oils marked "Classic" or green metal cans for 60's & 70's cars are normally group 1 oils with old tech additives that generate a lot of profit for the brand owners. If you have an old car using oil or very low oil pressure, fix it?
Some say different.
 
There is no reason to use anything fancier than Rotella, Valvoline Premium Blue, Delo or Valvoline VR-1 in 10w-30 or 15w-40 in older engines unless you have a specific goal to achieve or a problem to work around. Or because you simply want something "special".

Lots of guys I know with the local antique machinery club run Delo or Rotella 15w-40 in their antique tractors no matter if they are show rigs or working tractors.
 
I've had excellent oil analysis results running Amsoil's 10w30 ZRT in 60's big block Chryslers.
 
Originally Posted by ofelas
I've had excellent oil analysis results running Amsoil's 10w30 ZRT in 60's big block Chryslers.

I'll be using that or Dominator 10w-30 in the FE for the Torino when it's done. Was using VR-1. Sometimes even Valvoline white jug.

Using Valvoline Premium Blue in the ‘47 Ford tractor at the moment but going to Valvoline white jug 10w-40 for a few years since I picked it up super cheap.
 
The muscle cars with the high performance cams and stiffer valve springs like the 375 hp 396, boss 302,426 hemi may eat the cam if todays SN oils are used. Those cars need more ZDDP to protect their cams and lifters.

The regular run of the mill engines should be fine on the SN oil.
 
Not just engines with higher spring rates, while that certainly does exacerbate the cam lobe wear issue. Anything using rocker arms can be very hard on cam lobes because of the pressure multiplying effects of the rocker arm ratio.
 
This really depends on the particular engine in question. If it's a stock engine with a stock cam, any API SN/SN+ oil will be fine. If it has an aftermarket cam with flat tappet lifters, you'll want a cam with more ZDDP (>1,000 ppm Zn).

I ran Amsoil Z-Rod 10w-30 when I had my '66 Mustang. If I still had it, I'd probably be using Driven GP-1 10w-30. The bearing clearances from that era weren't really wider, but had a wider tolerance. I've seen them be as tight as .0010" and as wide as .0026" from OEM. I would use a 30 grade so long as you have sufficient oil pressure. If the oil pressure is wanting to fall below 15 psi or so at hot idle, I'd go to a 40 grade.
 
Originally Posted by andyd
Engines of 50s era had larger tolerances. For that reason alone, I'd use 20w50 or at least a 10w30 or a 30 or 40w HD. Checking the oil at every fillup was a good practice in those days
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Funny I just re-maned a 67 buick 340-4 block and the crank pins checked out at 0.0022 > .0.0023 which is a one-thousandth running clearance. I did clean up some pins on a ford 351 and that had a wide tolerance of almost a thou instead of a 1/2 thou or less.

That's about the best you can do given block distortion and crank harmonics.

I think I've seen some honda's running under a thou, I have never measured the bearing width or dia on those.
I might guess they need to be a tad wider and possibly fatter to work with the 20 grade low HTHS oil


Piston tech has moved a bit with the silicon hypereutectec and plasma moly short skirts but I'm hearing more noise with them.

Oh and I forgot , we tore into this "low mileage" engine to check out an odd noise.

It had two wiped cam lobes. Car had under 70K on it.

That's with high ZDDP oil and over the nose of under 160 lbs!

So after its broken in I'd go for the moly.

Race cam you should have roller followers. But.

"Motorcycle" and ATV 4T oil has HIgh ZDDP and is a light 40 grade.

its usually API S- rated in to the (now obsolete) high zinc period of pre SL

Perfect !
 
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The main issue is flat tappet camshafts with higher than stock valve spring pressure and/or higher lift ratios.
Shell Rorella T 15w40 used to do the trick, but I would not trust it any longer.
I have 2 classics with original engines; they need about 1200 ppm Zinc.

I recommend reviewing this analysis:
Flat tappet oils

If I ever pull apart one of these engines again I will stab a hydralic roller and be done with it.
And run 10w30.


68_Vette back.jpg
 
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I have Valvoline VR1 in my 355 with a big cam and flat tappets. 4 qts of 10w30 and 1 qt of 20w50. I could only find 4 qts of the 10w30 locally. Seems like everyone goes straight to the 20w50 around here in the classics.
 
I run a 10W-40 with a zinc additive in the 396 BB that is in my 70 Monte. I tried running a 10W-30 in it after the rebuild but the oil pressure was lower than I liked at a hot in gear idle.
 
Use this:
Red Line Engine Break-In Additive provides conventional motor oils with anti-wear additives like zinc and phosphorus (ZDDP) that are necessary to protect against premature camshaft and valvetrain wear. While designed for optimal engine break-in, this formula is ideal for extra anti-wear protection at any time. 1/2 bottle each oil change should do the trick. Part # 81403

Half Bottle (8oz.) when treating adds the following;

Capacity - Phosphorus - Zinc
12 quarts - 382 ppm - 460 ppm
10 quarts - 458 ppm - 552 ppm
8 quarts - 572 ppm - 690 ppm
6 quarts - 763 ppm - 920 ppm
5 quarts - 915 ppm - 1104 ppm
4 quarts - 1145 ppm - 1380 ppm

1 bottle (16oz) when treating adds the following;

Capacity - Phosphorus - Zinc
15 quarts - 610 ppm - 736 ppm
12 quarts - 763 ppm - 920 ppm
10 quarts - 915 ppm - 1104 ppm
8 quarts - 1145 ppm - 1380 ppm
7 quarts - 1307 ppm - 1577 ppm
6 quarts - 1525 ppm - 1840 ppm
5 quarts - 1830 ppm - 2208 ppm
4 quarts - 2288 ppm - 2760 ppm
1 quart - 9160 ppm - 11040 ppm
 
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Are new synthetic oils harsh(er) on seals especially for older cars?
Also aren't API SL (or lower?) easier on seals than SM/N?
 
Originally Posted by OilUzer
Are new synthetic oils harsh(er) on seals especially for older cars?
Also aren't API SL (or lower?) easier on seals than SM/N?


No. PAO can be harsh to seals (any elastomer seals), but there's few oils out there where PAO is the primary base oil. The ones that are, they usually have a good bit of ester which is an excellent seal conditioner. Group III synthetics are not a concern for seals.
 
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