Just picked up my rebuilt 4.2 from the engine shop. Head rebuilt all new valves guides, cam bearings and 12 new valves. Block got the full meal deal also, hot tanked then re-bored, decked, new conrod and mains bearings, timing chain, oil pump, etc, etc. No expense spared… don’t tell the missus.
After loading the engine on my F-150, discussions with the shop tech revolved around break in and which oil to use for the first 500. Having been a 20-50 man since buying the car in 1985, I was surprised that he suggested an oil I have never heard of. Hot Rod 20 / 40, available from most quality parts stores.
He is a long time engine builder with a stellar reputation and has built everything from mega racing engines to screaming rice rockets but the reason for his recommendation is that it contains zinc which is beneficial for the cam lobes and buckets. I intend to follow his advice when I fire up the boiler in a week or two, but has anyone come across this? best regards Brian / Mytype
Sounds like BS to me but I’d use it simply because he said to and if your engine craps itself it’s one less thing he can use to wriggle out of the warrantee.
2 Likes
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
4
Never heard of hot rod oil, but he’s right about the zinc – or more properly, ZDDP (I hope I got that right). I think there are some who advocate using oil intended for diesel engines because it has more ZDDP. Modern engines are designed not to require as much ZDDP, so modern oils have less and less of it. Our flat tappet engines need it.
I too have heard that you need oil with ZDDP (zinc) on fresh flat tappet engines. My memory is that ZDDP was common in most oils years ago but was gradually phased out of the more common grades. I have 4 flat tappet engines of various designs but last one I did any internal work on was in 1997 . I have been using Castrol 20-50 in all of them and have had very good success but if I have to do any valve work on them going forward I will be studying up on the ZDDP topic again. Years ago when I first heard about this I think Shell Rotella T was one oil that at least back then still had good ZDDP content. My 2 cents.
Zinc content in today’s oils can be found in product specifications. For example, here is a sheet with Mobil oil specifications. The wide range of zinc concentrations available in modern oils have served my old-car engine break-in and regular use well. You can see the wide range available from Mobil, small brands may also have suitable zinc levels.
The other relatively widely-available oil in this category is PennGrade (fka Brad Penn), which has 1500 ppm zinc. This is the oil that Terry Lippincott has recommended that I use (he did my motor rebuild in 1996 - still running great).
Dave
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
9
A Lucas product? Well, that changes things! Lucas is known for really good products. Sounds like good advice.
Zinc is incompatible with catalytic converters, hence in theory, normal oil doesn’t have any. It’s been banned for a number of years. On the back of oil containers there is a small circle - if the circumference of the circle is jagged it has zinc, if smooth it doesn’t. All today are smooth. I’m surprised at the Mobil specs - are they for the US and Canada?
Anyway Brian you need zinc, and not just for break in. I have direct experience about this - that is the surface of lifters on XK engines breaking up. Additives are available for this at most jobbers. I’ve used the Lucas hot rod oil - available at Lordco, but it is expensive.
Though the levels of Zinc and Phosphorous are declining in modern oils, it is wrong to say they don’t have any. Here is an up to date document of the level of each in current Mobil 1 oils, and the API, ILSAC specs that they meet. Zinc levels of 750-900ppm are the norm, but some are as high as 1300 and still meet API SN.
Unfortunately there is so much conflicting information out there on this topic that I really don’t know what to believe apart from manufacturer’s specs.
The Mobil oil product sheets from my post are 2014 data and David Langley’s post are 2019 data. Both data sets cover ZDDP zinc levels ranging from 750 - 1850 ppm and list no oils without zinc. Separately at Mobil website shows the Mobil 1 FS European Car Formula 0W-40, which Porsche specify for my new Porsche, as having 1,000 ppm of ZDDP zinc. My cars are in California which must have among the most stringent catalytic converter and smog regulations.
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
18
That’s a different Lucas.
1 Like
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
19
IIRC, the heavier grades of oil – 20W-50 and whatnot – tend to have higher levels of ZDDP than lighter grades like 5W-20. That probably simply reflects the fact that it’s our old Jags with tappets that call for the heavy oils while my more recent vintage Honda Civic calls for the 5W-20.
The market situation is as Terry said. Zinc and phosphorous levels have been reduced because they “foul” catalytic converters and are not needed with modern engine strategies to minimize friction. Diesel oil once high in zinc, has also been reduced. No free lunch there.
The question is how much ZDDP do I need in my Jag? No one except us…cares.
So its all hearsay and individual opinion. My number is 2000 ppm. So I use Mobil One 15w-50 and add 4oz of Lucas break in oil. Probably wasting my time and money, but I do the same in my BMW oilhead. Mainly because I can buy Mobil One at Walmart on the cheap.
Interesting to see the varying levels in ZDDP in the chart below.
