• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

Very interesting very long blog posting - racing oil and zinc

Share this page

steveg

steveg

Yoda
Gold
Country flag
Offline
Last edited:
Steve, you beat me to it! I was going to post a link myself. I haven't yet read it all but it seems to confirm what we had discussed in the previous thread but with the added information that the ZDDP level itself is not important. If so then we have a much wider choice of fully synthetics to use and can experiment with some of the lower weights such as 5W-30 to see if it improves starting and fuel consumption.

Before this all goes ballistic again can I just say our cars will also continue to run fine with ordinary mineral oil 20W-50. We are just discussing incremental improvements.
 
Sounds like the same Guy that 10 years or so ago swore adding acetone to gas was giving Him 35 mpg in His 25 year old Chevette. But I'll keep reading, hopefully He can be trusted.
 
A lot of the various discussions focus on 'flat' tappet engines but without really explaining what is so special about those regarding which oil is used. At the end of the day you still have two pieces of metal separated by a film of oil. Can somebody explain what is special about the flat tappet issue. I find it hard to believe that modern fully synthetic oils with their superior anti-shear characteristics would not be be able to handle flat tappet lubrication.
 
I had Dema at ElginCams do my BJ8 camshaft about 3-4 years ago and he sent me a paper with oil brand recommendations but I have misfiled it but I'll keep looking(dang Windows 10)

I sent him an email a couple of weeks ago about oil we should use and the below response is what he sent back. I think he is a source we can trust for correct info on our Healey engines.

Hello, You can go online to all of the oil companies and get their list of oils and the specs. 1200 parts per million 1200p\m was the best amount of ZDDP for a long time and now a lot of the oils are down to 600-900p\m. the heavier oils like grade 20-40 or 20-50 have more ZDDP as compared to grades5w-20,10w-30.or even10w-40. Try to find an oil with 1100 p\m but change it often when the oil is hot. The absolute min is 900p\m

I hope that this helps, Dema



 
DerekJ said:
A lot of the various discussions focus on 'flat' tappet engines but without really explaining what is so special about those regarding which oil is used. At the end of the day you still have two pieces of metal separated by a film of oil. Can somebody explain what is special about the flat tappet issue. I find it hard to believe that modern fully synthetic oils with their superior anti-shear characteristics would not be be able to handle flat tappet lubrication.
Click to expand...

Surely almost all engines have flat Tappets.
 
Hi All,

Flat tappets or Roller Tappets? I often wondered why I have not heard of anyone rebuilding a Healey engine who decided to replace their Flat tappets with rollers. Is it to retain the original design of the engine or is it that the roller lifters and adjustable pushrods are not available? I appreciate that cost could be a deterrent but is there a more intrusive underlying factor?


Ray(64BJ8P1)
 
Patrick67BJ8 said:
I had Dema at ElginCams do my BJ8 camshaft about 3-4 years ago and he sent me a paper with oil brand recommendations but I have misfiled it but I'll keep looking(dang Windows 10)

I sent him an email a couple of weeks ago about oil we should use and the below response is what he sent back. I think he is a source we can trust for correct info on our Healey engines.

Hello, You can go online to all of the oil companies and get their list of oils and the specs. 1200 parts per million 1200p\m was the best amount of ZDDP for a long time and now a lot of the oils are down to 600-900p\m. the heavier oils like grade 20-40 or 20-50 have more ZDDP as compared to grades5w-20,10w-30.or even10w-40. Try to find an oil with 1100 p\m but change it often when the oil is hot. The absolute min is 900p\m

I hope that this helps, Dema
Click to expand...
This is what I received with my Camshaft and Lifters. April 2, 2012
 
DerekJ said:
A lot of the various discussions focus on 'flat' tappet engines but without really explaining what is so special about those regarding which oil is used. At the end of the day you still have two pieces of metal separated by a film of oil. Can somebody explain what is special about the flat tappet issue. I find it hard to believe that modern fully synthetic oils with their superior anti-shear characteristics would not be be able to handle flat tappet lubrication.
Click to expand...
The problem is related to speed and load. Crankshaft and camshaft bearings have high enough speed and low enough load (at operating speeds) that a full film of oil will separate the parts. Flat tappets on a camshaft have a high enough load in pounds per square inch (or equivalent) that that a full film of oil can't be maintained on the camshaft lobe nose. Lubrication enters a mixed film or boundary lubrication region and metal-to-metal contact occurs. Zddp mates with the metal surface to reduce wear under those conditions. The mechanism of how zddp works has been the subject of study, of course, but I have not seen a definitive answer.

What 540Rat tests is how much load can the tested oil support before metal-to-metal contact occurs.
 
RAC68 said:
Hi All,

Flat tappets or Roller Tappets? I often wondered why I have not heard of anyone rebuilding a Healey engine who decided to replace their Flat tappets with rollers. Is it to retain the original design of the engine or is it that the roller lifters and adjustable pushrods are not available? I appreciate that cost could be a deterrent but is there a more intrusive underlying factor?


Ray(64BJ8P1)
Click to expand...

The guys in Australia who make the aluminum blocks have a roller tappet mod. It's not cheap and IIRC it didn't look very elegant. The problem with roller tappets is they have to be prevented from turning about the vertical axis. Unless the block is designed for them, preventing that from happening adds complexity that adds weight to the valve train, which is not good.
 
John Turney said:
... Zddp mates with the metal surface to reduce wear under those conditions. The mechanism of how zddp works has been the subject of study, of course, but I have not seen a definitive answer.
Click to expand...

It's over my head, but:

"Currently, the most important antiwear and
antioxidant additive that is added to is a class
of molecules called zinc dialkyl dithiophosphates
(ZDDPs) [14]. Antiwear films generated from ZDDPs
are known to protect rubbing surfaces in engines, acting
as sacrificial films when being rubbed that are constantly
regenerated in a rubbing environment [15]. Studies have
shown that the breakdown products of ZDDPs, and not
the ZDDPs itself, provides the antiwear
needed to lubricate sliding steel surfaces within a simulated
and actual engine environment [16,17]. Several
studies show that ZDDPs decomposes upon rubbing to
form a protective film (tribofilm or antiwear film),
however thermal decomposition has also been the
accepted major mechanism of the antiwear film formation
[18–20]. It is well known that these films are comprised
of an amorphous polyphosphate glass structure."


My take on all of this is that--while the need for ZDDP is somewhat debatable--there is no downside to having an adequate level of ZDDP, since our Healeys don't have catalytic converters which can be damaged by it (I'm not aware of any other adverse environmental issues). It may be like taking vitamin C or, ironically, zinc: it may not do any good, but it probably doesn't hurt anything and it makes you feel like you're doing something when you first get the sniffles.
 
Ray, DWR sell roller rocker sets. i know several people that have them installed.

John, Thanks for the explanation. As I understand it ZDDP is still present in most synthetics but at a level more like 700 ppm. Is that enough? Who knows? Presumably the oil companies do but I haven't come across any detailed articles from them on the subject.
 
DerekJ said:
Ray, DWR sell roller rocker sets. i know several people that have them installed.

John, Thanks for the explanation. As I understand it ZDDP is still present in most synthetics but at a level more like 700 ppm. Is that enough? Who knows? Presumably the oil companies do but I haven't come across any detailed articles from them on the subject.
Click to expand...
I suspect that the additive companies are doing work on a replacement for zddp, but they won't tell us what they are.

One of the things we heard at the Yosemite meet is that there are only four companies that make oil additives. The "oil companies" don't actually make them.
 
Bob_Spidell said:
...
My take on all of this is that--while the need for ZDDP is somewhat debatable--there is no downside to having an adequate level of ZDDP, since our Healeys don't have catalytic converters which can be damaged by it (I'm not aware of any other adverse environmental issues). It may be like taking vitamin C or, ironically, zinc: it may not do any good, but it probably doesn't hurt anything and it makes you feel like you're doing something when you first get the sniffles.
Click to expand...

After reading the whole thing plus many of the comments, my take is we can have our cake and eat it too. VR1 and Joe Gibbs Hot Rod both have around 1200ppm zddp and are highly rated in his test-to-destruction system.

One of the comments therein is that zddp is an old technology and some newer ones have evolved. I'm going to stick with VR1 for the present until getting more corroborating evidence on the newer additives.

I intend to try 10w30 VR1 next oil change and see if it maintains oil pressure. What he says about bubbles in the thicker oil makes sense and jibes with Lake Speed's comments about the bottom of our engines being bathed in an oil foam during running.

His comments about not using additives make a lot of sense and jibe with Lake Speed.

His anecdote about the seized Toyota running again was also quite interesting.

Will read the Corvette forum counterarguments.
 
Thanks Steve for posting the 540rat blog. It was actually this blog which prompted me to re-think my use of ZDDPlus added to Castrol GTX and to start that oil thread a few weeks ago. One of the Joe Gibb's oils (for modern LS engines) did rather well in the 540rat blog, which is why I contacted that company several weeks ago. It was Lake Speed at Gibbs who instead recommended their "hotrod" oil for my rebuilt engine. I appreciate the 540rat blog because it got me to recognize that creating my own oil concoctions might not be the best way to proceed. But there certainly are plenty of criticisms of the methodology he/she uses, which is why, in the end, I decided to trust the advice of one of the companies which designs/specs the oil itself.

In the end, I am the first to admit that this is all somewhat silly since few of us will use our Healey's to compete with those MBs and Volvos for the most miles driven between rebuilds. But it is nice to understand each component of our cars a little better and to treat our cars as nicely as possible. Thanks everyone for being part of one of the few forums out there that can discuss oil without it all spiraling out of control.
 
Fully synthetics don't need as much ZDDP because they are in themselves better wear reducers than old mineral oils that worked fine for Healeys in their day?
 
Back
Top