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TR2/3/3A Zinc additive and lead additive

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I run it fairly hard but not for extended periods of time. Probably about 1000 miles in summer weather. Running Castrol 20/50 oil.
 
karls59tr said:
I run it fairly hard but not for extended periods of time. Probably about 1000 miles in summer weather. Running Castrol 20/50 oil.
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I’m trying to remember if the Castro 20/50 is the one with high zinc additive. One of the major brands boasts the zinc additive on the jug, so no more zinc is required to be added. And, of course, synthetic is not god for our British engines.
 
Mobil 1's 15w/50 has zinc.
From the internet: "1300ppm of zinc, also known as ZDDP (Zinc Dialkyldithiophosphate), is generally considered sufficient to protect a flat-tappet engine. However, some sources recommend 1600ppm for high-performance engines."

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Castrol does have a 20/50 with zinc for "classic cars". Look for that on the label.
 
Valvoline VR1 20W50 also has zinc/phosphate properties. Used it in my Formula Ford because it didn’t foam.
(Morning Ken, ran into Lou and the guys from Huntsville at the Mitty, we missed you)
 
Thanks Jim...miss seeing you ....and Linda too.
I don't travel as much as I used to.
 
Most modern oils have more than adequate ZDDP. You can check their web sites to be sure.

The issue has been wildy overblown:



I know less about "lead" additives, except to note that they are not really lead and exist mainly to increase octane. I dn't know if they do anything for valveseat recession. In any case, if you don't run the car long and hard, you won't have any valve-seat recession. Again, an issue that has been overblown by repetition.
 
My mechanic, who is himself an owner of little British cars, uses Joe Gibbs Driven HR15W‑50 high-performance synthetic motor oil (> Driven Oils - Born from Joe Gibbs Racing <) that is good for long‑term storage and old engines requiring a high ZDDP level and that would be changed every five thousand miles or ten years. It protects against cam-lobe wear but not recession of non-hardened valve seats.
 
Lead worked it's way into the iron and stays for quite a while.How long is anybody's guess.
IMHO drive and enjoy. If you start to see signs of the valves going out of adjustment,(no ticking) then it's time
to plan on a rebuilt head with steel seats.
Valve recession doesn't ruin the head in any case, so why fret it??
Mad dog
 
Of course the OCD in me likes to have the head (a spare) built to spec in advance of necessity.
Then all can be taken care of in a day, and the car has no down time.
Mad dog
 
Hi
I understand there are 20W-50 weight oils available for classic cars with higher ZDDP for flat tappet motors. But, for reasons I will not get into here, I have always preferred to run 10W-40. As such, I have used 6qts Castrol GTX and added a bottle of ZDDPlus (4.0 oz).

Last year I had both Blackstone and SpeeDiagnostix do a Used Oil Analysis (UOA) after 1,348 miles. Results as follows:
Blackstone
Zinc: 1554 ppm​
Phosphorus: 1280 ppm​
SpeedDiagnostix
Zinc: 2065 ppm​
Phosphorus: 1462 ppm​

These tests were performed on the exact same sample. I think 1200/1300 ppm is where you want to be - so I may be a tad on the high side. And, not that I have any evidence, but I preferred the Blackstone test as the commentary they provided with the test result was extra intel SpeedDiagnostix did not provide. Blackstone comments included:
"The first sample from your Triumph looks pretty good, overall. Universal averages show typical wear for this kind of engine after about 1,500 miles of use on the oil, and metals in this report (mainly aluminum - tin) compare nicely after a similar oil change interval, which means internal parts are wearing well. Silicon is a bit high, so check air filtration on the off chance that's a sign of dirt contamination. It might also be something harmless, like sealer. No fuel or coolant was found, and a slightly low viscosity is fine. The TBN is strong, so lots of active additive was left"​

Been doing this for 25 years and 15K miles since the motor was rebuilt. Going forward I may reduce the amount of ZDDPlus I add.

Regards

Bob
PS: I do have hardened valve seats so no lead additive, But, I do add 3 oz. Marvel Mystery Oil at each fill up as an upper cylinder lubricant. The ST Workshop Manual (p. 0-205) actually suggests this may be beneficial, esp in "wintry" weather driving
 
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