engine oil for our old classics

[riverdogs00]

Group,

I've just taken receipt of my 70 SS, and now am in the process of determining what has already been done and what needs to be addressed first.

Engine oil is one of my first priorities, and as mentioned in a pinned thread here for engine break in, the ZDDP (zinc) additive that was prevalent back in the pre cat converter days with pretty much any motor oil has pretty much gone bye bye.  Now days it's high detergent, no /low ZDDP, and a move to synthetic/blends.

 

The newer engines with roller tappets do not need the additive, but our old original flat tappet motors do. The ZDDP creates a sacrificial barrier between the cam and lifter. While it's critical for engine break in, the additive also is being recommended now for every oil change.

 

1 common fix is to go with Delo or Rotella diesel oil as they have that additive. As I'm researching though, I'm finding that those oils are also high in detergent, which washes away the ZDDP. Some simply add a container of cam break in additive to pick up that additive. I'm finding now though, that break in oil additive also was low in detergents, to help rings seat. Great for break in, but I don't know that thats a great idea for every day use.

 

Racing oils tend to have the ZDDP additive, but then they also have a higher viscosity, which can increase oil pressure. I don't know that a significant increase in pressure is good for the older engines, but then again I don't know that it's not. Just thinking oil leaks might become more common.

 

I found an interesting read on a corvette forum ( http://www.corvetteforum.com/forums/c3-tech-performance/2484100-list-of-flat-tappet-oils.html )

 

 

My question to all of you is this:

 

Which oil do you run? weight/brand/name

 

Do you use a ZDDP additive?

 

 

Any other thoughts that I'm missing?

 

 

[Leghome]

I had my 350 rebuilt one year ago and the engine builder recommended Valvolene 10W 30. He has been rebuilding engines for over thirty years, he has 5 or 6 classics and that is what he uses in all of his cars. I had been running Mobil One but developed all kinds of leaks and it started using  about 2 quarts between changes of about every 3,000 miles. That has all been cured and also no leaks now as I had to change out the shifter shaft seal on the side of the 700R4.

[72-CLASSIC_RIDE]

I went with the Valvoline VR1 10-40 weight on my rebuilt 402 CI motor.  Used it during break in and since.  Haven't experienced any issues after 7+ years of use.

I also looked around for recommendations and convenience of availability was my biggest concern on brand chosen. 

 

Doug

[420ponies]

Brad Penn 20w-50 in mine since new. street /strip tolerances on all bearing journals. I had been using Kendall GT,trusted this stuff since 1980, changed to Brad Penn since same company just new technology. Has the zddp in it .They also have different weights like you would use 10w-30 or 40  if you wanted.It's the only thing GREEN in my Blue Monte! Just look up a Brad Penn dealer near you!

[Mike Brichta]

I use either Brad Penn Oil or add Cam-Shield to regular oil.

 

http://www.cam-shield.com/acatalog/Cam-Shield_Oil_Treatment.html

 

Mike

[72jrfan88]

I use Amsoil 10w30 or Quaker State Defy. That Defy is a lot of bang for the buck as it has a zinc additive formulated for older engines!

[cny first gen 71]

I also use the Quaker state defy, my motor has about 50 or 60 k on it. Havent had any problems at all.

[riverdogs00]

I decided on the Amsoil "Z-rod" 10/30.    ( http://www.amsoil.com/shop/by-product/motor-oil/gasoline/z-rod-10w-30-synthetic-motor-oil/?code=ZRTQT-EA )

Not that I will be able to tell any difference or not, but at least I feel better knowing I have some measure of protection.

This car has less than 50k on it and I have no smoke. Cam wear? who knows. 

We will see!

 

 

Mike

[Dans '70 Z20]

The issue is that all standard motor oils (Unless you by racing oil that states "not for street use") have reduced the amount of zinc in their oils a few years back.  They found the zinc was causing premature catalytic converter failure.  Newer cars with their roller cams do not need the added benefit that the zinc provides.  In a standard old V8 with the rods resting right on the cam, the zinc is key ingredient that significantly cut down on the wear/friction between metal on metal surfaces.  With roller cams have a roller tip on the rod it significantly cuts down the need for zinc.  For a few years many hot rodders switched to diesel oils bc the zinc was not reduced in diesel oils.  Since however ..... they have also had their zinc levels reduced.

 

The only way to insure you are providing adequate lubrication to your classic is to use a zinc additive at each oil change, use a aftermarket race oil that is designed with high zinc content or at minimum a quality oil like some of those mentioned above(but it still will not provide the lubrication oil provided when these cars were made).  Here on LI, for those looking for a quality non racing oil many aftermarket parts stores recommend/sell Brad Penn.

 

Anyone rebuilding an engine in there stock classic should consider upgrading to a roller cam for reliability & longevity.   I had three friends experience premature cam failure in one year a few years back. All due to the reduced zinc levels in standard motor oil.  

[MI_Custumz]

I currently run Valvoline conventional 10w30, but come spring I want to use one with more zinc in it. I was looking at Valvoline ZR-1 10w30, but noticed this:

 

"(Dino) Valvoline VR1

Grades: 20W50, 10W30

Claim: "High zinc/phosphorus provides extreme wear protection, including flat tappet applications."

Verification: 1300 - 1400 PPM ZDDP http://www.valvoline.com/pdf/VR-1_Racing_Motor_Oil.pdf

NOTE that there are some concerns with VR1 due to inconsistenttest results. Additionally, racing oils are not intended for extended (3,000+mile) change intervals nor start-and-stop cycles."

 

 

I change the oil in spring when it comes home from the storage unit and in the fall before storage. No way does it get to 3,000 miles in the summer. If I do drive it quite a bit, I may throw in a mid summer oil change. I see someone is using AMSOIL Z-ROD, but that's synthetic. Not sure I want to go from conventional to synthetic. Also, what are considered "start-and-stop cycles"?