ZDDP oil additives vs. roller lifters - opinions?

**elagache** · 02-06-2011, 04:32 PM

Dear Team Buick engine gurus,

I've been "educated" on more more gotcha associated with rebuilding a classic engine. I was unaware of the Zinc Dialkyl Dithio Phosphate (ZDDP) oil additive used before 1990. Since these products poison catalytic converters, the EPA got them phased out by 1990. Modern engines apparently get along without the stuff through only one recognized change: they use roller lifters to avoid the cam to lifter fiction that ZDDP reduced.

Of course when rebuilding an engine you could upgrade to roller lifters (TA Performance will gladly take your money!

). My question is how confident are Team Buick members that ZDDP only effects lifters and cams in an older engine? What is the majority solution to this problem? Are most folks upgrading to roller lifters (when possible)? Do folks use some of the ZDDP additives to make sure their engine is protected? Do some folks do both?

If you are as new to all this as I was, there is a reasonable summary here: http://www.macysgarage.com/myweb6/ZDDP.htm. If you would like the perspective of someone trying take your money every oil change - here is one of those: http://www.zddplus.com/.

As always, thanks for the informed opinions!

Cheers, Edouard

**carmantx** · 02-06-2011, 04:53 PM

We run Valvoline racing oil. Has the zddp in it. You can also get brad penn oil, and some others.

We use a zddp additive only during initial engine/cam break in. Then the valvoline from then on.

No roller lifters in any of our buicks. Not even our race car.

**elagache** · 02-06-2011, 07:31 PM

Howdy again just a quick footnote,

My nautically-inclined brain remembered something about zinc being used as a sacrificial anode to protect ships from rusting. Therefore zinc should have the same sort of effect when added to oil. This would explain the claim that ZDDP oil additives should provide some additional corrosion protection. That corrosion protection should be throughout the engine, not simply at the lifter-cam surface. So that is one reason to use these products even if you have a modernized roller-lifter. It probably doesn't matter for racing engines that get rebuilt frequently, but could matter for an engine you intend to use for a long time.

Here is the Wikipedia article on sacrificial anodes: http://en.wikipedia.org/wiki/Galvanic_anode.

Cheers, Edouard

**sledhead** · 02-08-2011, 04:20 PM

I to use valvoline have had no wear at all. When i overhauled my engine cam and lifter were replaced. Comp cam also makes a oil additive that works fine all of my freinds with flat tappet cams are using some type of additive. The proof is in the pudding!!!!! I hope this may help you

**elagache** · 02-09-2011, 08:25 AM

Thanks to everyone who has replied,

Checking the cost of going to roller lifters for my 430 rebuild . . . *Ouch*!!

Given that this isn't certain to eliminate all potential ZDDP issues, I'm inclined to make sure my oil ends up with some ZDDP one way or another.

I see that indeed Valvoline makes a synthetic racing oil. Is that the consensus for making sure my "brand new baby engine" is happy?

Thanks to all. Sure are a whole mess of details to resolve when upgrading an engine!!

Cheers, Edouard

**Straight Eight** · 02-28-2011, 02:56 PM

IO understand that roller lifters are not the complete answer, as the roller is wearing a grove in the camshaft in some cases.

I have used Shell Rotella 30, that also contains ZDDP, since the 60's in my straight eight, never a problem.

**elagache** · 02-28-2011, 04:50 PM

Dear Straight Eight,

Thanks for sharing another perspective that reinforces my gut feelings.

Originally Posted by Straight Eight

IO understand that roller lifters are not the complete answer, as the roller is wearing a grove in the camshaft in some cases.

I have used Shell Rotella 30, that also contains ZDDP, since the 60's in my straight eight, never a problem.

Unless the engine was specifically designed for oils without ZDDP, can you be really sure after-market parts will solve all the problems? Roller lifters are a little too rich for my budget and application, but even if I were to go with them - I would continue to provide the engine with ZDDP lubricants. It is a small price to pay for peace of mind!

Cheers, Edouard

**DocModisett** · 03-06-2011, 05:17 AM

Why take a chance????? If a man is wrong, the engine will be lost.... I would rather pay the extra 10 bucks and be sure the engine will live....and yes the cam/lifters is not the only thing that is affected by the removal of zinc from the oil... every part that rubs against another part is affected, because it wears faster.... i dont like having to buy a additive to put into the oil, but the oil companies shafted us and we dont have any other choice....unfortunatly I had to learn the lesson the hard way,,, rebuilt a engine in my truck , fired it up,, it ran great for 3000 miles.... and then lost a cam lobe....

**BornBuick** · 03-28-2011, 10:49 PM

Yeah to that. But be careful, synthetics are not the complete answer either and synthetics do not really have the requisite chemistry to be a proper ZDDP emulsifier and carrier. If you check most if not all do not have the requisite amount ZDDP for old school hard impact parts. Synthetics do two things very well at both ends of the spectrum. Lube and flow in frigid and high heat conditions contributing to lowering the coefficient of friction in those conditions but do not also do the work that ZDDP is doing in an oil admixture design.

With that said however, too much ZDDP can cause problems too. Diesel oil in a gas engine is not a good idea as well. Although averaging higher ZDDP levels than comparative Gas rated motor oils, they are high in ash content and acids not found in levels that are beneficial for gas motors.

The bottom line here is use the ZDDP additives in a good petroleum based oil which is low in ash and acids designed for gas motors but use it sparingly as too much does not work either and contributes it's own problems.

**elagache** · 03-31-2011, 04:50 PM

Dear David and Team Buick members,

Originally Posted by BornBuick

Yeah to that. But be careful, synthetics are not the complete answer either and synthetics do not really have the requisite chemistry to be a proper ZDDP emulsifier and carrier. If you check most if not all do not have the requisite amount ZDDP for old school hard impact parts. Synthetics do two things very well at both ends of the spectrum. Lube and flow in frigid and high heat conditions contributing to lowering the coefficient of friction in those conditions but do not also do the work that ZDDP is doing in an oil admixture design.

With that said however, too much ZDDP can cause problems too. Diesel oil in a gas engine is not a good idea as well. Although averaging higher ZDDP levels than comparative Gas rated motor oils, they are high in ash content and acids not found in levels that are beneficial for gas motors.

The bottom line here is use the ZDDP additives in a good petroleum based oil which is low in ash and acids designed for gas motors but use it sparingly as too much does not work either and contributes it's own problems.

I find your comments very interesting, but I'm not sure what are finally using in your own cars. Do you use any synthetic at all? Are you using a particular sort of refined motor oil and then adding ZDDP? What is your opinion of the Valvoline VR1 Racing Oil? http://www.valvoline.com/products/co...g-motor-oil/6/ Is your point of view that since these engines weren't designed at the time of synthetic oil, synthetic oil isn't as good an overall lubrication choice as oils refined in the same way as oils of 50 years ago?

Thanks for your thoughts,

Cheers, Edouard