If you're depending on zinc to protect your flat tappet?

[68-500]

This is what I’ve learned though my readings. Now Im not a scientist or anything fancy just a guy that reads.
If your depending on the zinc in your oil to protect your flat tappet cam, your looking at your oil backwards. Your first look should be looking at your oil’s ability to retain an oil film measured in psi. Then I would look for the anti-wear package (zddp) and less maybe more. Heres why, the more additive in the oil, the less oil in the oil, thinning it. I very much believe that if you buy the best oil, rated on oil film strength that is sufficient for your valve spring pressure there is little need for a bunch of zddp, just a little to coat your lifters and cam lobes. Its my understanding that zddp stays on the surface inert until oil film breaks down, then it sacrifices itself as a boundary temporarily. If your lobe and lifter have reached the the point where your metal to metal and its used up the sacrificial zddp coating now you’ve got wear and I speculate that under that condition the cam may still get oil on it but the lifter is now acting as a squeegee wiping that oil off before it can get back in between lifer and lobe.
I also believe that getting your 5 qts of good quality oil and that little bottle of zddp is a big mistake. I believe your thinning your good oil and asking for the oil film to breakdown.
Like I said I’ve no professional experience testing these theories. It’s just something Ive came to believe from my reading. And I believe all the snake oil (little bottle of zddp) may be only lightening your wallet at best or causing damage by thinning your oil film strength.
So after my rambling what do you think?

 

[Jerry Hall]

I use Valvoline VR 1 racing oil in all my flat tappet engines, with no other additives. There are several other good oils formulated for these engines and I prefer that rather than trying to guess what other oils need to be compatible. ZDDP is like most everything, you can have to much of a good thing and defeat the purpose.

 

[HawkRod]

This is what I’ve learned though my readings. Now Im not a scientist or anything fancy just a guy that reads.
If your depending on the zinc in your oil to protect your flat tappet cam, your looking at your oil backwards. Your first look should be looking at your oil’s ability to retain an oil film measured in psi. Then I would look for the anti-wear package (zddp) and less maybe more. Heres why, the more additive in the oil, the less oil in the oil, thinning it. I very much believe that if you buy the best oil, rated on oil film strength that is sufficient for your valve spring pressure there is little need for a bunch of zddp, just a little to coat your lifters and cam lobes. Its my understanding that zddp stays on the surface inert until oil film breaks down, then it sacrifices itself as a boundary temporarily. If your lobe and lifter have reached the the point where your metal to metal and its used up the sacrificial zddp coating now you’ve got wear and I speculate that under that condition the cam may still get oil on it but the lifter is now acting as a squeegee wiping that oil off before it can get back in between lifer and lobe.
I also believe that getting your 5 qts of good quality oil and that little bottle of zddp is a big mistake. I believe your thinning your good oil and asking for the oil film to breakdown.
Like I said I’ve no professional experience testing these theories. It’s just something Ive came to believe from my reading. And I believe all the snake oil (little bottle of zddp) may be only lightening your wallet at best or causing damage by thinning your oil film strength.
So after my rambling what do you think?

A friend just had his flat tappet fail after about 18,000 miles. So the cam was well broken in. Nothing else changed but the oil, so I feel it must have been that.

I do believe oil film is important, as well as ZDDP. My personal preference is to use a well respected oil formulated with ZDDP. You want about 1500 PPM of ZDDP. More is not better, as it makes the oil acidic and causes other problems if too much. The difficulty with ZDDP amounts is that it is not published on most oil bottles. My understanding is new oils for modern engines has about 500 PPM (to little for flat tappet cams).

So having said all that, regardless if the bottles of ZDDP reduce oil film (I don't know if they do), I'd prefer the pre-formulated oils since I don't know how much ZDDP I end up with if I add a separate bottle of ZDDP.

 

[lewtot184]

this discussion will go on forever with different opinions and "facts" don't seem to be consistent to me. anyhow, film strength is a big deal and there is info out there on that. i also believe that there's no real downside to zddp when adequate amounts are used. i think the real flat tappet cam problem is people. they want aggressive high lift cams that have to have a lot of spring pressure with high ratio rockers. I'm "one and done" on that scenario! all this puts the valve train in a near impossible high stress situation and i wonder if you can run enough zddp to save the problem. seems like most people think a roller is the solution; i don't. just quit building time bombs.

 

[WileE]

This is what I’ve learned though my readings. Now Im not a scientist or anything fancy just a guy that reads.
So after my rambling what do you think?

I think I'll continue to use ZDDP in my oil.

 

[4speed68rt]

I say trust the engineers at the oil companies and use the oil that is formulated for "racing and classic cars". There is a few. They cost a little more than the modern formulations, but they are made for flat tappet cams. No need to speculate and worry about what you are mixing up. You probably wont get as good of a formula as the professionals.

 

[threewood]

Joe Gibbs Driven and VR1 are my oil choices for my cars.

 

[MWbirdLOVER70]

I use Valvoline VR 1 racing oil in all my flat taplet engines, with no other additives. There are several other good oils formulated for these engines and I prefer that rather than trying to guess what other oils need to be compatible. ZDDP is like most everything, you can have to much of a good thing and defeat the purpose

I use Valvoline VR 1 racing oil in all my flat taplet engines, with no other additives. There are several other good oils formulated for these engines and I prefer that rather than trying to guess what other oils need to be compatible. ZDDP is like most everything, you can have to much of a good thing and defeat the purpose.

I also use Valvoline VR1 like it and use the 20W50 stuff

 

[DPeltz]

I use Brad Penn in any engine breaking in, or HP spring pressures.
Any daily drivers with flat taps get Rotella after break in. Never had a failure. We have buckets of Rotella around for our diesel trucks, so that somewhat influences our decision. I know the diesel oil no longer has the additive package it once did, again due to emissions, but so far, no problems.

 

[RemCharger]

I say trust the engineers at the oil companies and use the oil that is formulated for "racing and classic cars". There is a few. They cost a little more than the modern formulations, but they are made for flat tappet cams. No need to speculate and worry about what you are mixing up. You probably wont get as good of a formula as the professionals.

They are also engineers that make the additives. Designed to be compatible.

 

[#41]

So after my rambling what do you think?

You never can tell what is marketing or tech articles that might be disguised as marketing. I just use the oil recommended by shops that build, break-in, and warranty their engines. I don't need any information beyond what is actually working for the people who do it day after day.

 

[DPeltz]

Amen, my Friend!

 

[68-500]

They are also engineers that make the additives. Designed to be compatible.

I lean towards, compatible with increasing they profit margins.
I dont even really believe in diesel anti-gel treatments. How can a few ounces of something effect 30 gallons.
I believe in #1 diesel when cold and cut that with kerosene when just plain frigid.

 

[Rebelrouser]

This is what I’ve learned though my readings. Now Im not a scientist or anything fancy just a guy that reads.
If your depending on the zinc in your oil to protect your flat tappet cam, your looking at your oil backwards. Your first look should be looking at your oil’s ability to retain an oil film measured in psi. Then I would look for the anti-wear package (zddp) and less maybe more. Heres why, the more additive in the oil, the less oil in the oil, thinning it. I very much believe that if you buy the best oil, rated on oil film strength that is sufficient for your valve spring pressure there is little need for a bunch of zddp, just a little to coat your lifters and cam lobes. Its my understanding that zddp stays on the surface inert until oil film breaks down, then it sacrifices itself as a boundary temporarily. If your lobe and lifter have reached the the point where your metal to metal and its used up the sacrificial zddp coating now you’ve got wear and I speculate that under that condition the cam may still get oil on it but the lifter is now acting as a squeegee wiping that oil off before it can get back in between lifer and lobe.
I also believe that getting your 5 qts of good quality oil and that little bottle of zddp is a big mistake. I believe your thinning your good oil and asking for the oil film to breakdown.
Like I said I’ve no professional experience testing these theories. It’s just something Ive came to believe from my reading. And I believe all the snake oil (little bottle of zddp) may be only lightening your wallet at best or causing damage by thinning your oil film strength.
So after my rambling what do you think?

I don't mean this in a bad way, but the day of the flat tappet camshaft is over. Just like a lot of other things from my youth are over. I have been building engines since 1972, my first was a small block chevy that the oil pickup fell off of. The OEM stopped making flat tappet camshafts in the early 1990's that's over 30 years ago. The only market for flat tappet camshafts are performance and restoration people, a relative small market. In the USA how many machinists and the equipment is still around, not much is my guess. Companies have farmed this production out to overseas suppliers, whio make junk. And the few USA suppliers charge as much for a flat tappet cam and lifters as a common hydraulic roller set up. Plus, a hydraulic roller will tolerate more lift for a given duration more lift usually means more torque at the rear wheels. No special oils or assembly procedures to try and make it live. I worked at a Chevy dealer in the 70's techs threw cams in those engines, no break-in, no additives, no special oils and they worked just fine. I was fresh out of Tech School and my fellow mechanics made fun of me for spending the time to break-in a stock cam. The only people that worried about break-in were hot rodders with big flat tappet cams.

 

[68-500]

While I agree flat tappet cams days maybe numbered. I disagree that I could retrofit a roller for the same price. Cam core is more $, lifters more $, distrubutor drive gear change and wear issues there, cam buttons, timing set cover, thrust bearings, different push rods, then your getting into maybe i should do different rocker arms. Valve springs I see as a wash, you should replace them with most cam changes anyway. Although springs for roller cam may cost a little more due to aggressive lobe ramps and more lift.
Cars with a magnum or slightly larger cam should have no problem with flat tappets as long as the run quality oil and change it regularly. Now if your building a street/ more strip engine, yes you should strongly consider roller cam.

 

[WileE]

I don't mean this in a bad way, but the day of the flat tappet camshaft is over.

While I agree flat tappet cams days maybe numbered.

Been over for a l-o-n-g time .... for new engines. But, there's still a multitude of FTC engines out there, and we'll still need the proper formulation oils to keep them running.

 

[Don Frelier]

Oils well that ends well...

 

[toolmanmike]

Oils well that ends well...

 

[ykf7b0]

I just built an engine and went roller. I spent around $700.00 more but I wanted to avoid the tedious flat tappet cam break-in procedure.

 

[Dodge Bros]

The zddp is suppose to reinforce
the film thickness on the metal. If your driving your car too the point that the zddp is gone, you went way past your oil change, especially if that is for the cam break in.

If your adding a zddp additive to your oil after the break in, sending the oil samples off on a regular basis for testing can show how well the oil is holding up, and if it is doing its job. Some high zddp oils are low in detergents and need to be changed more frequently. VR1 valvoline is a great oil, but is one of those that needs frequent changes to keep up its protection.

The contact area between two parts creates heat and causes a chemical reaction with the zddp additive on that part. It may very well decrease the film thickness, but what it loose’s in film strength it should gain because it counters the oils high detergents from scrubbing the oil film off the metal. Break in oils have very high zddp levels for extra protection for break in. Additives for break in do something similar, but not as well imho.

I much prefer an oil designed for protecting a flat tappet cam than adding an additive to an oil that really isn’t engineered for your engine anymore. Some diesel oils have had changes to the additive package to suspend soot in the oil (like the current Rotella oils) and no longer are even rated for gas engines. The off the shelf brands of oil for modern gasoline have less zddp, and heavy on detergents that scrub the oil off parts, (like your flat tappet cam), but extend the oils life. That isn’t what you want either. You can add a zddp additive to either of those, and change the oil more frequently and have more success than running your engine with out the extra zddp. But it is kind of silly to do that when there are so vary many great oils for our old engines. Driven, Penngrade, Valvoline VR1, Amsoil Vrod, Lucus…just to name a few, that are properly engineered for flat tappet engines, and need no additive for zddp.

We use to just put flat tappet cams on stockish engines and start them up and run them with nothing to help break them in. The factory when our cars were new didn’t use any special oil to break cams in either. The extra zddp for break in these days is needed now because the cams are often aggressive, machining and metal is often sub par, cam cores have slowly gotten softer. To much taper gets removed without a good break in oil now, and even though you may have been successful breaking your cam in doing nothing special, it probably won’t last as long as it would have if it was broke in proper, and operated with oils high in zddp, or other antiwear agents.