Is it necessary to use motor oil with zinc and phosphorous in my 1974 Triumph TR6, 6 cylinder.
Until you get an expert answer here, you can research at bobistheoilguy.com. More than you wanted to know, but your answer might be in there somewhere.
Do you have Triumph’s recommendations? If so I suggest you follow them unless you get a solid answer to your question.
I always wanted a Spitfire. Never got one, but I did get a Miata.
Back in '74 and thereabouts, both zinc and phosphorus were normal ingredients in motor oil, so the car manufacturer would not have made a point of stating that these ingredients were necessary. Nowadays, they are not present in most motor oils, hence the OP’s question.
As I recall, using motor oil without zinc additives in an older car that originally used zinc-infused motor oil can lead to excess wear on the camshaft, with resulting BIG problems. I know that there are zinc additives available for use in classic cars. While I can’t give you any brand names, I know that they exist. Most likely a Google search for “zinc additives and motor oil” would yield some results.
Oil labeled “Racing oil” and the “universal” 15w-40 grade oil now favored by diesels contain the zinc additives your engine depends on. 4-stroke motorcycle oil also has the full additive package…
Aren’t all TR6s 6 cylinder? And Caddyman is right.
I would use them. The reason as I understand it that they are not used as much in modern oils is that they will poison the catalytic converter. But modern oils are far superior to those available in the '70s too, so the additives are probably not as necessary as they once were.
"But modern oils are far superior to those available in the '70s too, so the additives are probably not as necessary as they once were. "
When the EPA can dictate additive packages, when the health of the catalytic converter becomes more important that the health of the cam lobes, that statement might not be true…
oblivion, modern oils may be superior in modern engines, but the OP’s engine isn’t modern.
Basically, I would try to find oil that doesn’t have the “energy conserving oil” icon on the label. These oils tend to be made for older engines and motorcycle engines, and might have the additives you need.
You might also post this in a TR6 forum, you’ll want to be hooked into that group, anyway.
I have a 1974 TR6 as well. I use Valvoline VR1 Racing oil, 20W-50. It has the zinc additives in it. And yes all TR6’s have 2.5L inline 6’s.