<VV> Oil... Put the ZDDP Back In

[Tony Underwood]

At 11:00 PM 9/29/2007, BobHelt at aol.com wrote:
>
>In a message dated 9/29/2007 3:31:24 PM US Mountain Standard Time,
>Mikeamauro at aol.com writes:
>
>Has  anyone else been doing similar research on ZDDP-containing   products?
>
>Mike Mauro
>
>
>
>Hi Mike,
>How much ZDDP are you wanting to have in your oils? Or is it like the old
>saying...if a little is good, more is better and too much is just right?
>Frankly, the amount required for our Corvairs has never been 
>determined. How  much
>do you want? How much ZDDP do you think was in the oils available in the
>1960s? Corvairs ran pretty good back then. You can still get Shell Rotella T
>(CJ-4) which has 0.12%. That's as much as was in the early 1990s SH 
>oil. Isn't
>that enough? Why are you so concerned with getting more ZDDP? The 
>API had  GM run
>tests on engines with sliding lifters when they approved GF-4 oils. Isn't
>that some evidence that current oils work pretty good in our Corvairs?




The zinc issues arise when a new camshaft is installed, or a 
performance engine has some serious valve springs that put a lot of 
load on cam lobes.    This has been a topic to watch for some years 
now as ZDDP additives have been reduced (for whatever reason) as time 
passes.   Some of the newer "serious" engines in vehicles expected to 
be run hard are being delivered with roller-lifter camshafts to deal 
with these scuffing issues since roller cams present much lower 
sliding friction on the cam, and of course roller lifters don't slide 
at all, or shouldn't :).   They also use no taper profile on the 
lobes which offers up more surface area to deal with the loading 
presented by stiff springs etc.


But as time passes and engine oils continue to reduce these 
anti-scuff friction additives (which may well be OK for today's 
engines across the board) those older engines with flat-tappet OHV 
gear are gonna be at risk, particularly the performance engines of 
yesterday which depended on those anti-scuffing high performance oils 
to keep the cam and lifters and valve stems and rocker arms alive.


Again, this topic has been popular among the musclecar gang for some 
time now, and some of those guys are concerned about being able to 
safely run these older cars safely if they can't get an oil that's 
able to keep the lifters from wiping a cam lobe on something like one 
guy who owns a mint condition Desoto Adventurer with a Hemi engine 
fitted with some serious valve springs and a fairly radical factory 
cam which *nobody* seems to offer anymore.

He's been concerned about eventually not being able to get an oil 
capable of adequately protecting the cam and lifters in this engine.


...the musclecar forum offered up hints, such as the Brad Penn race 
oil, the earlier SL Rotella oil, and the additive that Hughes Engines 
sells, as well as the additive that GM used to sell (but evidently 
has been discontinued) which at least does keep things above-board 
for now... but if even these sources for anti-scuff protection go 
away, what's left for older performance engines with radical cams and 
stiff valve springs?     Even Corvair engines have been having issues 
with cam lobes getting wiped and lifters scuffing if they end up with 
stiffer springs installed to compliment the camshaft.


I don't have anything along Corvair lines with stiff valve springs 
since I'm not gonna ever be running anything more radical than an 
Isky 280...  which will do OK with factory springs on the street.


However, a Mopar 383 Super-Commando engine with a couple of "extras" 
will sure appreciate an engine oil with anti-scuff additives.    I'd 
not wanna wipe a cam lobe in that engine, even if the 284-292/480 cam 
*is* still available, as are the factory springs.  They aren't that 
cheap... and I'd as soon not have to buy another or do the work 
changing it all out if I could help it.

Are modern SM oils up to doing the job in an engine like that with a 
flat tappet cam and some heavy springs and valves to deal 
with?   Also, are these same modern oils good enough to keep a 'Vair 
engine's cam/lifters from galling and scuffing if the oil is kinda 
hot on that warm summer afternoon and it's been just a bit too long 
between oil changes which otherwise wouldn't have been a problem...?