The Stovebolt Site Forums The Shop Area Engine Shop Motor Oil And ZDDP - How Important Is It?

I rebuilt the 1958 261CID engine I have in my 54 3100 last July. Since then I have only put Valvoline VR1 10w30 oil in it. The machine shop that did the machine work insisted on it or the warranty on their work was immediately void. Valvoline VR1 oil is "said" to be the only motor oil to still have the VDDP additive in it. My machine shop tells me that if I stop using the VR1 my cam and lifters will be ruined.

My questions are:
Are there other oils with ZDDP in them (in proper amounts)?
If synthetic motor oils lubricate and protect so well why can't I use a good brand of one of those?


My engine is nicely broke in now and has 13K miles on it, and runs very smoothly. I have been using it to get back and forth to my college classes.



Any pointer will be very much appreciated
Walt Williams
La Verkin, UT

VR1 oil is good oil. ZDDP is important for initial breakin, but afterwards, dubious. I think you will be fine without the ZDDP. But, you have to convince yourself.

Lots of opinions on this. I use VR-1 in my flat tappet cam motors and have never used ZDDP additives.

I initially used Mobil One. But a couple years ago I read some articles that stated it had been reformulated and no longer was adequate for flat tappet cam motors.

Thing is, when you buy oil, you have to be diligent and read the bottle every time you buy it. They change the formulas but don't waive a flag in your face when they do so.

I've also heard that if you are running a stock cam and stock valve train the pressure loading on the cam lobes is so low that once the the motor is broken in you can run any oil you like and it will be just fine.

For me, the VR-1 works so I'll stick with it.

Hope that helps

John

The opinions are all across the board on this issue. You have to research the information and then decide. As long as you properly maintain your truck and don't abuse anything it will live a long life on whatever oil you use.

The current SN grade oil has about the same amount of ZDDP that the oil that was around when these trucks were new. If you're running a stock grind cam with stock valve springs, regular oil will be fine, synthetic would be even better. There's plenty of false information out there regarding oil and cam failures, most of it either from someone who doesn't really know what they are talking about, someone who had a bad experience with improper break in/improperly rebuilt engines, or someone who is trying to sell some sort of "miracle old car" oil by playing on the fears spread around.
Just for the record, I do run VR-1 in mine, as it does have a performance cam in it. However, the choice had more to do with the viscosity I'm running than any ZDDP fear. I run all of my other flat tappet vehicles on SN grade regular oil, and also put it in all of my customers vehicles with NO cam failures.

I am running a stock cam grind with stock valve springs. I also have 3.54:1 rear gearing and generally don't run my cool old truck faster than 70 MPH (2500 RPM). I mainly NEED this engine to last a while.

Walt

well, it's valvoline oil, so whatta ya worrying about?


some other oils that I've read have zddp in 'em, but check their sites to be sure :


brad penn oil

royal purple (synthetic)


-W

All oils have ZDDP in them. For all but the most high performance motors its a complete non-issue. Plus at ZDDP levels over 2000ppm the ZDDP starts eating metal.

There is a letter you can google from a GM lubrication engineer regarding the ZDDP issue, and it quite a good read. Its in the December 2007(!) issue of the GM Tech and Service bulletins or HERE

You can use it if you like. The big points are:

All motor oils are backwards compatible so current SJ oil will perform the same/better as older API specs.

There IS a specific lifter wear test in the API specs that must be passed... so again, all oil TODAY is as good as or better than old API specs.

Flat tappet cams are made today... they are called 'inverted bucket' design... so its not like modern cars have all switched to roller rockers.

ZDDP has been LOWERED because it will damage catalytic converters (a cam is cheap compared to a new catalytic converter) BUT while ZDDP HAS BEEN REDUCED other additives have been added to provide the same protection.. just with a different additive.

You do not need a special break in oil. You can use it, but unless you have a very high performance motor it does nothing so make the break in 'easier'. Just look at modern engines. They are simply started up and driven away from mile #1. Nothing special is done to them at all.

Maybe all oils have ZDDP in them, but if they do, the level is too low for break-in protection. Modern engines do not need the ZDDP because roller tappets are used, so low friction on the cam and no risk of damage. This is he main reason ZDDP has been significantly reduced from oil...it is no longer necessary.

I went to the local engine builder who does all the racing engines for around here and I was buying a couple cans of some specialty stuff w/ZDDP and got into conversation with them. They were of the opinion while it might be good for break-in, once a motor is ran in, it's not necessary. I was buying some to run in my flat tappet 327 and a 390 car I have (both well broken in) and he talked me out of giving him money.
Also talked to him about hardened valve seats and he was of opinion unless I was using as a daily driver, it would take decades before I'd encounter any harm running unleaded on old stock valves. I was surprised he had no interest in helping relieve me of some of my cash.

The current grade is SN, but yes, they are backwards compatible.
Also of note, the cam/lifter wear test specifies using a 3.8 Buick V6 engines with a flat tappet hydraulic cam.

If you are concerned about it, just use normal name brand oil with half a bottle of additive at each oil change. GM EOS is a good one, a long with Comp Cams additives.

I run my 250 on Mobil 1 10W30 and no additive.

What really needs the most are the extreme energy type camshafts with the radical lobe designs which throw the valve open extremely quick, then hold and drop it. It takes a ton of spring pressure to keep the lifter on the lobe so there is a tremendous amount of pressure on the lobe ramp.

Our stock engines with hardly any spring pressure put very little load on the cams, so I don't worry about it at all.

Joe

After installing a new cam and lifters in my 1957 322 V8 my engine builder asked me to run Shell Rotella T 15w40 with Erson Cam ZDDP. He says it's cheap insurance and since I'm not an oil chemist and don't want to have issues I'll follow his advise. He's been re-building antique car, truck and tractor motors for over 40 years. I've put almost 9,000 miles on the new cam, so far so good!

Mike B

Well that settles it!

When was it he told you that? My understanding is Shell Rotella changed their formula too.

Again, do your own due diligence and check the oil each time you buy it. If it doesn't state that it is compatible with flat tappet cams, proceed at your own risk.

If it has the starburst symbol on it and says "API grade SN' on it, it's ok for use with any gas engine, flat tappet or roller cam, excluding engines with the high lift aggressive profile camshafts and high pressure springs.

Could you give a definitive step-by- step "how to" for a novice to follow to determine if their motor indeed has a "high lift aggressive profile camshaft and high pressure springs" so they don't use the wrong oil and wipe a camshaft lobe?

That would be most helpful.

I had the engine work done 2 years ago.

I looked on line at Rotella T and it lists "SM". Regardless of the oil brand I'm still going to use ZDDP in every oil change in my old flat lifter engines, right or wrong it make me feel better using it...

Mike B

If your motor goes 'whumpa-whumpa' at idle... that's what the mechanic who restores old engines told me.

As much as I would like to discuss ZDDP and the reasons why you DO NOT NEED to be adding it.. for some reason 'feelings' always degenerate the discussion into third hand rumors from mysterious 'old mechanics' that know more than actual engineers.

Its not a black and white 'you DON'T NEED TO add it' answer, but the short version of a very long story is no, unless you have things like double valve springs and cam lobes that look like squares and not eggs you don't need it to add anything to the oil.

What I would like to compile is a list of all the 'feelings' why people add it... and then destroy each one with quantitative scientific research that disproves it.

Short story: I was in a 'discussion' that GL-5 gear oil should not be used in M35A2 drive lines.. I said it most certainly SHOULD (the popular 'opinion' was that GL-1 aka mineral oil! was the right lube). It was a blood bath... till I was able to prove that the MILSPEC oil in the driveline since the mid-1980's was in fact, GL-5 gear oil and none of the horrors like 'yellow metal getting eaten' or 'incompatible seals' and every horror story of 'I knew a guy' COULD NOT HAVE POSSIBLY BEEN TRUE. The trucks had GL-5 gear oil in them for 20+ years and none of the stories could ever had been true... yet everyone with an account was posting that GL-5 would 'rot the yellow metal'. 20+_ years later still waiting for that rot to happen

Delo400 and valvoline blue heavy duty work fine.
My engine goes whumpa whumpa at idle.

My confusion is why anyone would suggest to a novice that they should use regular oil if the novice isn't sure what cam or valve springs they have. And there are a lot of folks in this hobby that don't know.

The "whumpa - whumpa" theory isn't definitive. Unique, yes, but not definitive. Lots of roller cams out their going whumpa whumpa...

There really is no dis-advantage to running an oil formulated for "flat tappet cam motors" like Valvoline VR-1, as long as the vehicle that doesn't have catalytic converters. So just use VR-1 and have the added confidence that whatever the cam and valve springs are they'll have the added protection.

Seems like this debate almost always becomes overly complicated for no apparent reason.

I don't think VR-1 oil will hurt catalytic converters. If so, someone needs to tell that to my '98 BMW 740il that has been running VR-1 for 11 years now with nary a cat problem.

That is correct. Valvoline has a proprietary ZDDP formula that prevents the phosphorus from burning off. That's what actually fouls the converters.

I see where you're going with this. I won't disagree that if you don't know, better safe that sorry. I don't know about anyone else, but around here, conventional VR-1 is about the same price as regular Valvoline, so the cost isn't too much more. However, my suggestion was based on what OP stating that his engine was freshly rebuilt with a known stock grind cam. In that case, regular oil will be fine.

the latest i've read was an article by Ed Preston, he sez the new SN oils can actually wash off any "zinc" on the cam and lifter and wear lobes on broken-in cams in 5-15k miles.
The API test engine is a 3.8 Buick V6 with less than .375 cam lift and 215 spring pressure.

Snake oil salesman. He's trying to sell you his product.

Been using 10W30 in everything I drive and my weed wacker. Almost a half million miles on the Malibu and only rebuilt the carb and changed valve stem seals. I also change all oils often.

Seems like every other month this topic comes up. I agree with Hotrod John, if it will help you sleep better run the additive. I run Lucas or power service with every tank of diesel, does it help? How would I know? But I know my injectors are still working after 200k miles, hauling lumber, towing dump trailers and a mini excavator/bobcat once a week. I do it for piece of mind. Run the additive! It's like over building something. People go, "isn't that over doing it?" You'll never know if it's over done, but you always know when it's not. Go the extra mile, can't hurt.