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What is the ideal zppd content in a motor oil for a flat tappet engine?
Ideal zddp content for a flat tappet engine?
- Thread starter Threeofnine
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I'd start at 1000 PPM like Mobil 1 FS 0w-40
Depends on valve spring pressure. 1000 to 1200 PPM. I use Castrol Classic
No less than 1,000. I think 1,000 - 1,400 is optimal. Depends on what other components are included in the antiwear pack, like Moly, Boron. Valvoline VR1 tested at ~1400.
I stocked up on Amazon Basics Euro 0W40 with 1,300 ZDDP and no Moly. I am running it now in one of my cars and will continue using it. The other car will be running Castrol Euro and M1 Euro 0W40, both are close to 1,000 ZDDP with some Moly. I will compare camshaft lobes after 20k miles.
I stocked up on Amazon Basics Euro 0W40 with 1,300 ZDDP and no Moly. I am running it now in one of my cars and will continue using it. The other car will be running Castrol Euro and M1 Euro 0W40, both are close to 1,000 ZDDP with some Moly. I will compare camshaft lobes after 20k miles.
Historically I wanted something near 1200ppm. But with modern base stocks and modern addpacks, who knows?
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Thanks for the responses. So Mobil 1 15w50 should be sufficient? I believe it has 1300ppm. I am planning on using it in an 85 Ferrari Mondial with a 2.9L flat tappet v8. My mechanic uses Pennzoil Euro 5w40 (in everything), but I believe it only has around 800ppm.
So long as the weather is appropriate for that grade I don't think you could get any better than a Mobil 1 15w-50 for that older Ferrari's flat tappet engine.
Even flat tappet engines don't usually need all that much ZDDP. The issue is that the ZDDP degrades over an OCI, so if an oil starts out with more of it, it'll last longer before wear rates start to increase.
Modern oils tend to have better antioxidant packages help the ZDDP last over longer OCIs. Even API SP oils with only 600-800 ppm phosphorus need to pass a valvetrain wear test on a flat tappet engine. I'd still use an oil with at least 800 ppm phosphorus, but unless you're really pushing your OCIs, or the engine in question is known for valvetrain wear issues, I wouldn't worry too much about going beyond that.
Modern oils tend to have better antioxidant packages help the ZDDP last over longer OCIs. Even API SP oils with only 600-800 ppm phosphorus need to pass a valvetrain wear test on a flat tappet engine. I'd still use an oil with at least 800 ppm phosphorus, but unless you're really pushing your OCIs, or the engine in question is known for valvetrain wear issues, I wouldn't worry too much about going beyond that.
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