Classic/Antique Car Repair: Ford 289 - lifters and ZDDP, Zinc content of oil in flat tappet engines

Question
Dick,

In a recent answer you mentioned using an engine oil w/ZDDP replacement additive. I have a recently restored Ford Country Squire (http://meadowneck.smugmug.com/gallery/3915851_QhtiM#227864296_aTF4h) with a rebuilt 289 v-8. By now, the engine has been broken in. I can't seem to get an answer about whether I should add a ZDDP-replacement additive. I'm told that engines of this era w/solid lifters should use the additive and I'm assuming the engine has solid lifters. What do you think?

Thanks

Rick

Answer
This is another one of those issues where a controversy has stirred up a lot of noise, similar to the scare stories about running our older engines on unleaded gas.

The facts are that the zinc content of oils has been reduced recently, and for engines with flat tappets (not "solid" lifters - that term refers to hydraulic lifters versus mechanical lifters, and your engine has hydraulic lifters anyway) there is a potential for rapid wear of the camshaft during break-in of a freshly rebuilt engine.   Since your car was broken in already, it is beyond that stage, any damage would have been done already if it had been broken in on the oil commonly sold today.   If you wish to be super cautious, you can buy oils with extra zinc in them from various vendors - do a Google search for ZDDP additive and marvel at the prices.   Or, you can use any of the "racing oil" sold by various vendors - it has added anti-wear compounds.  

If you can find Diesel rated oil in stock that was made before about July of last year, (still in stock in some stores), with an API CI-4 specification, that has adequate zddp for all engines (and much better detergent properties than non-Diesel rated oils).   I use Chevron RPM Delo 400 15W40 oil in all my vehicles now - I stocked up on API CI-4 spec cases when the new CJ-4 spec came out with the greatly reduced ZDDP last fall.

I rebuild engines, so I am more concerned with this than most - in your case, I wouldn't lose any sleep over it, but see if you can find some of the older oil around, or stock up on the oils that state they have ZDDP additive.

Dick