mebs

Hey gang,

This is my first post, but I've been benefiting from your collective wisdom for years now.

I own a 1968 Cutlass 4dr with a low compression 350 2bbl (122k miles). Since owning (7yrs) I have used 10W40 motor oil as recommended by the owners' manual--my mechanic said that I could use either synthetic or regular. So far so good.
I was buying more oil at the AutoZone last week and the cashier said something about modern engine oil causing premature wear on flat tappet lifters because of reduced levels of zinc (since cat converters were introduced). As such, he recommends either adding zinc additive to my normal oil, or running 15w40 diesel oil instead (as it has higher zinc levels).

Does any of the above make sense to any of you? I'm pretty dubious, given previous experience with part-store advice/knowledge. In the meantime, I can't confirm if my engine has flat tappet or hydraulic lifters; anybody know for sure or how to check (without taking anything apart)?
After that, wondering if I should be concerned about this whatsoever or carry on as normal.

Thanks a bunch!
-M

Charlie Jones

Your car has flat tappet lifters . Yes , some "modern" oils can cause camshaft wear .
Read this , you may find the information useful .
https://540ratblog.wordpress.com/201...-test-ranking/

OLDSter Ralph

Charlie, that is a lengthy article. I figured out how to save it all on my computer. Its a Microsoft Works word processor document. LOTS of info !

442Harv

Yes the guy was correct. I was using Chevron Delo, for years, but they changed it also. I now use Brad Penn, it has what you need foe flat tappet cams, there are also a couple other brands that you can use need to check around, most are racing oils.

Hammerdrop

Have been using Rotella 10w30 and 15w40 for years on all my flat tappet engines. My educated guess is that any diesel rated oil is fine for your flat tappet engine.

Due to a container and UPC code change, a person at Shell recent answered my inquiry if the Rotella formulation has been changed and the answer was that there had been no reduction in the zinc or phosphorus content. If it is good enough for a diesel with 15:1 compression...........you know the rest.

redoldsman

Your car has hydraulic lifters which are flat. You can add ZDDP to your oil or use one that already has zinc in it. A lot of folks (me included( use Valvoline Racing Oil which has a high zinc content. It is also readily available at most places.

Tedd Thompson

The last time I checked Rotella 15- 40 had 1080 ppm of zinc which is good enough and that is what I use but not only for the zinc but for the detergent package it contains. I never have lifter noise anymore sense I switched some 7 years ago.

The oil thing is like the blonds and red head thing you will get as many opinions as people you ask..... Tedd

B964

Reading that will make your head spin.




What oil does Mr. Jones plan on using?

mebs

Hiya all,

Dang.
Thanks for all the helpful information and suggestions so quickly! I really appreciate it.

I think I will change to a diesel oil this weekend, I remember seeing Rotella at the store at least.

Thanks again for all your help!
​​​​​​-M

oldcutlass

You can also use Valvoline Racing Oil (silver bottle for street use ) VR1 which can be had at your local auto parts store. You can use the same oil change intervals as any other oil.

Gascoop

Mebs....This oil thing has been beaten to death by "experts" on all the car/hot rod forums. As said, due to the cat converters AND also the newer diesel engines with the regeneration equipment, YES the oil companys did have to reduce the ppm of zinc and phosphate ..... not eliminate it as some guys will tell you. Shell oil and probably all of the other oil companys did reduce the ppm from "around" 1400 -1600 ppm to again around 1000 - 1200 ppm zinc/phosphate, as mentioned above still plenty. I used Rotella T 15w40 in my '02 Powerstroke for 15 yrs with never a hickup. My newer '16 King Ranch dually uses synthetic so Rotella T-6 is what it gets.

Most engines that are already broken in or high mileage engines I don't think really need the extra protection of the zinc/phos. but I guess it can't hurt. All this voodoo came about a few years ago when guys were wiping out the cam lobes on new engine rebuilds or cam swaps....... and as usual some guys just don't do any research or read anything when starting an engine for the first time ......"well I let it idle for about 20-30 minutes cuzz it started over heating". Anywho, my new 461" Olds will have Valvoline VR-1 in it when we crank it up on the dyno plus maybe a small bottle of ZDDP just for caution. Wow! I'm an "expert" now also!

Koda

VR1 is good stuff, but it is not always easy to find. NAPA seems to have, and there's always Amazon. Flat tappet usually refers to cam shafts, as opposed to roller cams. Solid lifters and hydraulic lifters in our old cars are both with flat tappet cams. Modern engines usually don't have lifters or pushrods as they are overhead cam engines, with the GM LS being a notable exception. The zinc is for the sliding of the cam lobe over the lifter, which does not happen on roller cams.

Edit: As a mechanical engineer, I am ashamed of that guy's bombast, pompousness, and general rambling that comes of being an embattled old man trying to defend a cause. That link needed about three paragraphs of lead in, and a list of data. Let others judge, present your data and move on.

Hammerdrop

Absolutely nothing wrong with Valvoline VR1 but I don't think it is available in a lighter 10W30 for use in cooler climate conditions and I think 20W50 oil is a little slower to get moving than 15W40 on startup. Get one of those magnetic heaters and put it on the bottom of the oil pan before starting the new engine with that 20W50 oil.

Been using the 15W40 in my Dick Miller engine with flat tappets for 20 years.

Now-a-days, I wouldn't have an engine built without a roller cam, but back then, rollers were still in their infancy.

oldcutlass

VR1 10w30 is available, however some national chain auto parts stores have to bring it in from their warehouse.

OLDSter Ralph

That blog by Rat540 is a lot to read !!!!!!! I copy and pasted the whole thing to a Microsoft Works folder on my computer. Then you can sit down and read it more leisurely.


There are several different Rotella's, (Rotella T, T4, T6, and I think T8) so do some research. I think I was studying the Rotella T4 at one time. Amsoil had a good one or two according to his testing. Valvoline VR-1 looked good also. I need to go back and read the blog another time or two.


For me, locally available, reasonable cost and high zinc/phosphate are the considerations. High zinc/phosphate, then local availability, then cost is my selection order. I want one motor oil for my Oldsmobiles and motorcycles.


Most wear is encountered in the first minute of start up. So oil film retention on cams, lifters and rockers is important.
....just my two cents worth

coppercutlass

Just buy VR1 and be done with it. I ran rotella mainly for weight but ALWAYS ! used a ZDDP additive. I went from 20w50 to 10w30 on my last 355 and picked up a little power . The time slip showed it. I could not find 10w30 vr1 so I just bought regular Valvoline and added the lucas zddp additive.


Also for what its worth I would drive my car in 30 degree weather on cold fall mornings to the track and the 20 w50 didn't really make it " noisy or take too long to build oil psi " .

Fun71

I had always wondered about this as well. Sure, a new engine build/cam swap/high spring pressure setup needs a lot of zinc and phosphorus, but does a high mileage, low performance engine really need it?

We've all seen posts about a new cam wiping a lobe, but how many posts have you seen about someone with a high mileage lo-perf engine wiping a lobe?

oldcutlass

I wiped a #6 intake cam lobe a few years ago on an engine that had probably 40k miles on it. It does happen with no apparent reason.

Charlie Jones

Mobil One , European formula . (#3 I believe) Mostly because of it's availability . (Walmart)

cutlassefi

Koda

Reminds me of the Unitarian Jehovah's Witnesses; they knock on your door for no apparent reason.

1967Supreeeme

oldcutlass

Sometimes mixing zddp w/oil actually makes the mixture worse for your car. Why make your own voodoo when there are products on the shelf that already work well.

olds 307 and 403

I actually had a lifter noise with a stock Olds 260 with SN rated 10W40 from the Coop. Even their 5W50 synthetic motorcycle oil is SM rated and claims a special ZDDP package that react with catalytic converters. Emissions are becoming very serious. Unfortunately most diesel oil is CK-4 or SN rated, that means 800 ppm zinc and similar phos. I was surprised there was an issue considering how wimpy the stock 260 cam is. I have used SL or SM rated 4 stroke motorcycle oil without issue. It usually comes in 10W40 or 20W50.