Zddp

[enjr44]

ZDDP (Zinc Dialkyl Dithiophosphate)

Does anyone here add this stuff to their flat tappet engines to prevent cam scuffing? My understanding is that the EPA beginning about 10 years ago has essentially had it slowly removed from all current available gasoline motor oils. It is now gone.

Ed

 

[adsm08]

ZDDP (Zinc Dialkyl Dithiophosphate)

Does anyone here add this stuff to their flat tappet engines to prevent cam scuffing? My understanding is that the EPA beginning about 10 years ago has essentially had it slowly removed from all current available gasoline motor oils. It is now gone.

Ed

I don't put any additives in my oil anymore. Found I don't need to. The EPA did have it slowly removed from oils rated for gas engines, roughly in conjunction with the disappearance of the flat-tappet cam. The zinc isn't really needed on a roller cam.

The key word to this whole thing though is highlighted in red and bolded. You can still get out of the bottle oil with ZDDP in it, the bottle just won't say gasoline on it, it will say diesel.

Lots of diesels still have a flat-tappet cam, so the zinc, along with some other heavy duty detergents are still found in diesel oil. It will not do your gas engine one bit of harm to run diesel oil in it either. I put almost 30,000 miles on my one 2.9 running CJ-4 spec 10W-30, and I have almost 15K on it's replacement with the same stuff.

My dad ran cheap bottom shelf store brand oil in the first engine for 150,000 hard miles. I did the same for 25K. The last 30 of that engine's life I ran the CJ-4 because we had it on tap at work. I tore that thing apart after I took it out just to see how much damage I did running it wide open for 8 years. I wanted to see if I had hammered the main bearings at all. No lie dude, I could read the part numbers on the main bearings stuff was that clean inside. The oil I had been draining out was always dark and nasty, but when I tore it down the bottom end was spotless.

 

[dirtcowboy]

I learned to use in the break-in oil. I don't add it after the initial break in which, on a FLAT TAPPET cam, is 20 minutes at 2000 RPM, continuous.

 

[tmcalavy]

man, where did you get a pix of my mo-in-law for your avatar?...that's creepy.

 

[cammeddrz]

Zinc is a huge necessity for flat tappet cams, (and completely pointless on a roller cam) and since near nothing comes with those anymore, and since metallic particles are reactive/damaging catalytic converters the EPA said "yank it out".

Even diesel oils only have 1500ppm of ZDDP, the gas oils of old had 3,000-4,000ppm of ZDDP. so diesel oils are better

I run the redline break in oil additive with every oil change, each bottle treats 12 quarts, so a $20.00 bottle lasts 2 changes, when mixed to their ratio it gives 4,000+ppm of ZDDP, which is the ratio needed to prevent premature cam wear/scarring. I run Mobil Delvac in everything, which being diesel spec already has 1500ppm, so I guess I could cut the amount I add in half, and make a bottle last 4 changes

be wary of zinc "replacement" additives found at parts stores, they don't actually contain zinc, and i'm not sold on them

 

[adsm08]

1500 is still better than the 150 the EPA wants.

 

[LearjetMinako]

API service motor oils "SL" was the last tier to have ZDDP in them. "SM" & "SN" (Current) either has it removed or very little left.

Just a quick question. Are flat tappet cams the same as direct acting bucket cams?

 

[adsm08]

Just a quick question. Are flat tappet cams the same as direct acting bucket cams?

They are similar in action and form, but the buckets are made of different stuff. I don't think DAMB setups need the zinc to not get eaten up.

 

[Road Angels]

zinc

All the race guys running flat tappet engines with high tension valve spring, use a zinc additive, or high zinc oil through some companies, thats for off road only , for classic cars and race cars, hot rod magazines are a good source for suppliers, my buddy that races 2.3 hydro planes swears by it, uses it in his hilborn injected alky 400 hp, 8,000 rpm limas, an he has been national champ a dozen times,

 

[Frank The Tank]

I put ZDDP additive in everything every oil change... I figure if it prevents premature cam wear on flat tappet engines... It probably prevents wear on other moving parts. I've had good luck with this. Maybe it'd just good maintenance/luck? Every vehicle I've had in the last few years has been 200k+ and I'm either still driving it or sold it running strong.

 

[85_Ranger4x4]

It is mainly for cam break ins, after they are broken in it doesn't matter as much.

Pretty much every diesel that comes in here is flat tappet, nobody knows or really cares about the zinc ordeal. Most just use regular diesel 15w-40 be it CIH, John Deere or whatever else they find. The only ones with flat cams are the ones with bukoo hours on them to the point that even 20 years ago it would have been very understandable that the cam needs replaced. Even with some hitting 30-40 even 50 years old it is fairly rare to have a flat cam.

I run regular 10w30 in my flat tappet tractors, they are 60-65 years old and don't complain. The newest one was rebuilt 20 years ago, I think the other two are just rerung originals.