Recommended Zinc level for flat tappet engines

[Jaymus]

I have a 302 that I want to last as long as it can. Mainly, I've been reading about a scare on how these flat tappet engines are biting the dust since the oil manufacturers have lowered ZDDP in the oils for those EPA/CAFE clowns.

I'm sure the problem isn't as bad as the internet makes it sound, but what amount of zinc should be in an oil that goes into a flat tappet engine? I have been looking up VOA's here, and found that Castrol GTX 5W-30 has 835ppm zinc in one test, here http://www.bobistheoilguy.com/forums/ubb...rue#Post1041595 .

I have been using 10W-30 GTX. Does anyone have any information about this?

What I'm asking is, what is a good zinc number to shoot for? And, is it really as bad as it sounds?

 

[MGregoir]

1200 ppm is a good place to look. Oils rated GF-3 and GF-4 are generally the ones to avoid.

Look for a CI-4+ rated 10W-30 diesel oil such as Chevron Delo 400 10W-30. It has 1200 ppm of ZDDP, and is a very high quality and reasonably priced oil at about $10 per gallon.

 

[Jaymus]

Do you think this would also help my engine? Here's where I'm torn.. Castrol GTX always shows good UOAs. But, that doesn't mean that it will do good in something that needs more zinc. But, then the question lies, do I really NEED more zinc?

I wind this engine out sometimes, will Delo be able to take a little abuse here and there?

I ask this because I used an HDEO in my 750cc Honda Shadow (15W-40 Rotella T), changed it, literally, every 1,000 miles, and 5k miles later, I was smoking when I revved it up, and smoking on start up/warm up.

 

[MGregoir]

It should be able to, it's meant for engines that cost more than your whole vehicle. Commercial-use oils generally don't compromise.

What year is your 302? SM rated oils are loaded with moly and supposedly pass the same test earlier oils higher in ZDDP did for testing on a flat tappet valvetrain in an engine running a continuous 3600 rpm.

Are the GTX UOAs for your engine or just in general? If GTX is showing well in your engine with low iron wear, you're chasing after a problem that doesn't exist and giving in to the paranoia.

If you are really really worried, an oil like Delo 10W-30 will have the zinc level of oils from the mid-90s and the benefit of superior base stocks and additives, as well.

 

[Tempest]

There is a lot more to AW than zinc levels. Much of what is going on is not seen on a UOA. Terry Dyson has stated that Pennzoil Platinum does not rely on ZDDP for it's AW abilities as an example.

 

[Jaymus]

No, the UOA is not mine.

Yes, there is more to protecting engines than having high amounts of zinc, BUT, zinc seems to be the best thing to protect flat tappet engines. Is this a myth, or is this a fact?

My 302 is a 1986 model 302 in a 5000 pound 4x4 truck. Doesn't do as much work as it does high RPM off roading, lol. But, I don't consider hauling 1000-1500 lbs now and then work, either. I don't feel it at all.

 

[MGregoir]

It is the best thing but a 302 in a 1986 F-150 is not something I would expect to flatten the cam, especially because the SM oils were tested in similar circumstances. If you are really concerned, I would switch to an oil like the Delo but ZDDP isn't everything, especially with things like the soluble moly and all kinds of other stuff they have put into these oils.

SM oils have been showing such good performance in almost everything except some of these machines that are brand new flat tappet cams with extremely high pressure valve springs in some pretty hot motors, didn't get broken in properly with the right oil and killed the cams fast.

The internet, confusion and panic have blown this way out of proportion. For those that are truly worried and in a scenario that needs it, there are the 10W-30 HDEOs like Delo that will do a great job and for everyone else there's the most current S-rated oils.

 

[Jaymus]

I wouldn't mind switching to Delo 10W-30 to ease my mind, but does it generally show good UOA's? I actually thought it didn't do that good. I'm gonna look up on it again.

Pretty much, if Delo 10W-30 does just as well as GTX 10W-30 in a gasoline engine like mine, I'll go for it. I just don't know if it does.

 

[glennc]

I'm not sure about Delo 10W-30 but a lot of the HDEOs are now SM rated and consequently have lowered their ZDDP levels, while some PCMOs, such as the high mileage oils, have somewhat boosted levels compared to other PCMOs (though still SM of course).

I am skeptical that most "flat-tappet" engines need high zinc levels. I think it is really those with crazy cams or very heavy valve springs that might have problems. In that case an oil like Red Line would be a pretty obvious choice IMO. That will give you your high additive levels in addition to higher regular film strength/HTHS.

From everything I have been able to learn, ZDDP type anti-wear is still the primary source of protection in any oil once the oil film breaks down. Other "ashless" chemistries seem to be helpful at optimizing the anti-wear but not in any dramatic way. Moly may also be helpful, but still, your real protection comes from good film strengths and enough traditional anti-wear to do the job.

I think the excellent performance of ordinary SM PCMOs comes not from new anti-wear chemistry but from improved base stocks. I feel that the most ordinary of these oils will probably work very well in your engine. As always the only way to be certain is through UOA. If I really wanted it to last as long as possible, meaning many hundred k miles, I would personally go with Red Line.

HTH,

 

[DmanWho]

You could just pick your favorite "base" oil and add an ounce and a half or two of ZDDP. Cam-Shield, ZDDP Plus, RL's break-in stuff, etc.

Maybe shoot for 1600 or 1700 ppm to start. Greater than 2000 ppm might be over doing it though.

 

[boxcartommie22]

everyone look in the oil additive section i wrote what redline says how much redline breakin add additive will inc zinc and phos. very interesting and better yet the additive is a base synthetic polyolester

 

[Tempest]

If you change the oil every 1K you could use one of the quality chlorine adds and not worry about wearing your cams. If you want longer drains, well....

 

[OVERKILL]

Convert it to roller and the HO firing order I did an HO drop-in to my '88 F-250, it was a major improvement.

 

[Chris71]

Try Brad Penn's Penn Grade 1 Partial-Synthetic Green racing oil.

 

[321]

I am not sure Delo400 10W-30 would not show good UOA's.

I just purchased some Delo400 5W-40 Synthetic from my local distributer 6-1Gal containers for $109.00 $4.56 per Quart.Hard to beat that price for the grade of oil.

Delo 400 5W-40 synthetic
CI-4 PLUS, CI-4, CH-4, SL (SAE 5W-40)
Zinc=1310
Phosphorus=1560

 

[MGregoir]

I can't imagine Delo 400 10W-30 not being a good oil. It is SL rated with a TBN of 10.2 and 1200 ppm of ZDDP.

The CJ-4 oils are generally the ones with the "reduced" ZDDP but the thing is because they are not GF-4 and rated Compression as the main rating instead of Spark, they contain 1100-1200 ppm of ZDDP still. The limitations on the CJ-4 oils is the sulfated ash content overall, not specifically the ZDDP which is why CJ-4 oils are lower TBN (less detergent) and slightly reduced ZDDP from 1300 or so to 1100.

Not confusing SM and GF-4 is important for this, an oil can be SM rated and carry a lot of ZDDP still but not GF-4.

 

[TallPaul]

Originally Posted By: MGregoir
1200 ppm is a good place to look.
That's a good number, close to Valvoline VR1 Racing Oil (1300 zinc, 1200 phosphorus). So yeah, VR1 would be an excellent choice and according to the Valvoline website, even the 10w30 has those levels of zddp.

 

[mechtech2]

It's not the fact that it is a flat tappet engine, but how much spring pressure and lift of the cam there is.
High spring pressures are the killer, and fast opening ramps.

 

[OVERKILL]

Originally Posted By: mechtech2
It's not the fact that it is a flat tappet engine, but how much spring pressure and lift of the cam there is.
High spring pressures are the killer, and fast opening ramps.


Yup, like the Lunati Voodoo camshafts!

Ultimately, roller is simply better. But many people find it hard to justify the expense, especially considering the price of link-bar lifters.

This is a unique situation however, since his engine is an '86, and the Mustang and Crown Vic for that year were roller cammed, his block is quite likely roller-capable. A set of lifers, the dog-bones and the spider tray, and he could run the stock HO camshaft, which is a major improvement.

 

[MGregoir]

That is correct, all blocks '85-onward were roller capable. The trucks didn't get roller cams until 1994. He would have to get the parts to do it but he could swap the cam and associated parts reasonably easily.