Mike McCoy

The other day I responded to a post about the problems someone was having with a new engine. I mentioned cam wear as a possible problem. I used the word Zmaxx and was corrected to ZMAX, a product for engine systems. I realized later that I had given the wrong name to the product I was refering to.
This product is called ZDDPlus. They have a very interesting and informative web site discussing the changes to modern motor oils. The government has mandated that zinc and sulfur be drastically reduced to extend the life of catalytic converters on modern cars. The problem with this mandate is that flat tappet motors need these chemicals to cushion lifter to cam contact. There are now serious concerns that old flat tappet engines are showing up in repair shops with damaged cams.
Since I own a fairly rare L72 engine, I was concerned about damage to my motor. I had read or heard somewhere about this additive and I found their website. They have a lot of technical studies comparing vitually all modern motors oil's zinc and sulfur contents. They make conclusions about the percentage requirements for zinc needed in earlier flat tappet (hydraulic and solid) engines. Roller cam engines do not need this additive due to the way that the lifter rolls on the cam.
I want to apologize to all for making that mistake. Please look at their website for an eye opening take on modern oils and additives.
I have purchased ZDDPlus on the net (we know where) for about $10.00-11.00 a bottle (in packs of 4).

Donald #31176

Mike,
Using an API rated oil CJ-4 or CI-4 is all that's necessary to protect a flat tappet OEM engine. No additives necessary.

kenmo

I bought four bottles of ZDDPlus from Corvette Central. Price was $9.95 each...

mrruffhouser

I think you are better off and it will cost you less if you use the proper oil. The ZDDplus costs @$10.00 to treat 4-5 quarts of oil. Brad Penn and Amsoil have oils with the right amount of zinc (12-14 parts per million) and in weights that are correct for your application plus (and this is big) no separation problem. Get the right stuff.

Mike McCoy

Diesel motor oils are formulated differently than gas engine oils. They are not recommended for gas engine use. I was unable to find the specs for Brad Penn and Ainsoil to determine the level of zinc and phosphorus in them.
All motor oils (pre 1988) had standard amounts of zinc and phosphorus added to the oil to obtain about .18% zinc, and .15% phosphorus in the oil. If the above oils you are refering to are highway legal, by law, they cannot have the zinc and phosphorus levels near those percentages.
It appears some racing (only) oils may have the above levels, but they also do not contain the detergent level needed for street applications. A high level of detergent is not needed due to their being changed much more frequently than street cars.
For me the $10.00 (one oil change) per year to obtain the old standards is pretty cheap insurance.

devildog

Mike, you are partially correct. Throwing in a $10 bottle of some "zinc" additive will probably not hurt anything (although ZMAX has been sued by the FTC because of increasing corrosion).

However, Diesel motor oils are the preferred motor oil for non-catalytic flat tappet engines (our older Corvette engines). The off the shelf ROTELLA, DELO, etc that meet API CJ or CI have about 1200 ppm of ZDDP (zinc dialkydithiophosphate) which is an extreme pressure additive. This 1200 ppm level is adequate. Using these is a better approach than using non-diesel oil and guessing at the ZDDP level by making your own cocktail with a highly promoted/marketed zinc-phosphate additive.

The biggest reason these flat tappet cams loose lobes is (1) improper cam break-in and (2) these classic engines setting for months (years) without pre-oiling before start-up.

I have 100's of gallons of ZDDP and ZDP at our lube oil additive plant where we make the additive packages for much of the lube oil market. I run diesel motor oil in my flat tappet solid lifter Corvette engines, and have for 40 years and 180,000 miles.

My aircraft engines are flat tappet as well, I use diesel oil in them because it is better... and they cost more than nice big block solid lifter C-2.

Joe

bigearl56

Thanks Joe.

Earl

Mike McCoy

Thanks devildog, I'll look into that.

JohnZ

Not true. The CI-4 and CJ-4 API-rated Rotella 15W40 (the most common Rotella weight at retail) is also rated SH/SJ/SM, which is the OEM gasoline engine test spec. The EPA doesn't want you to use CI-4/CJ-4-rated oil in an engine with a catalytic converter, but functionally there are no issues; we're not talking about catalytic converters on C1's and C2's.

Frankie the Fink

You guys have me paranoid now. Don't know whether to use up my 6 bottle supply of ZDDPPlus (during my routine Mobil-1 oil changes) or trash them and go straight to CJ-4/CI-4 Rotella ?!

Kensmith

EBAY I would do what John says. If the CI-4 and CJ-4 has the correct formula, why mess with trying to mix something up? But I see your point as you have the additive and need to get rid of it. Hate to just dump it. Maybe Craigslist?

1snake

This horse has been beaten to death so many times it's sickening. PLEASE EVERYONE, just use CI-4 or CJ-4 oil and forget everything else. It's as simple as that. The next person that brings this up should be "flogged", put on "the rack" and then have "thumb screws" installed.

Jim

Mike McCoy

Who dat say who dat?

Frankie the Fink

Hey Jim - what's the best oil filter to use ?
That's another thread I'd like to see hung out to dry...


Frank

C66 Racing

That's only applicable to 30 grade oils. 40 and 50 grade oils do not have the same limitations. As I think I mentioned in another thread here, AMSOIL sells these automotive oils (not diesel oils) with zinc on the order of 1375 ppm and phosphorus on the order of 1265 ppm:
AMSOIL SAE Synthetic Premium Protection 10w40
AMSOIL SAE Synthetic Premium Protection 20w50

These oils have the necessary ZDDP for flat tappet cam engines and have the necessary dispersants and detergents for daily drivers. I use the 10w40 in my 02 Z06 on the track because of the high ZDDP.

1snake

I agree. If you want a good laugh, go to the C5 & C6 forums and search
"wax". Those boys take their wax seriously.

Jim

gonefishn

Thanks for the reminder. There's a wax that can ...................

Steve439

I thought the CJ-4 didn't have enough?

Vetterodder

Appearantly it depends on the brand. A guy over on the Chevelle forum had numerous oils tested and there was a big difference between Rotella and Delo. The lab reported CJ-4 Rotella around 800ppm and CJ-4 Delo over 1200ppm.

C66 Racing

Do you know if that was zinc or phosphorus? The CJ-4 limit for phosphorus is 1100 ppm, so if the lab is right, their oil is exceeding the spec.