Zinc

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russhal

russhal

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Recently there has been a lot of talk on zinc in older engines with flat tappet cams. I found this link on zinc in oils very interesting. http://speedtalk.com/forum/viewtopic.php?f=1&t=35836#p433871 I know a lot of people just put an additive in what ever oil they buy. You might change your mind after reading the results. Too much of a good thing can be bad. Choose your oil wisely. I thought brad penn oil was top of the line oil. Not so much anymore. What brought me to this article was the fact I was not happy with the oil pressure my 408 had. It's hot in the south and I've always used a straight or 20 50w. On this engine I tried 10 30w but was not happy with the pressure I had.Thought maybe the 10 30w oil wasn't thick enough or had enough viscosity. I thought I would just change weights. I changed oils all together and went with Valvoline vr1. The results are amazing. I had oil pressure of 25psi hot at idle and 60psi at cruise. Now it's 50psi at idle and 75psi at cruise. I've always done the basic mods on my blocks to improve oiling. And I have a high volume pump not high pressure. You may be alright with 25 to 60 psi but I've always had better and the one engine I've built had problems with good oil pressure, lived a short life.
 
Great read.

I've only changed the oil on my 360ci/380hp crate once since the original break-in. I'm about to change the oil again and was looking to see what oil others liked and why.

I'm about to make a 3,000 mile trip from TX TO WI and back and want to feel secure in my decision.
 
Why would a motor need 75 psi at cruise. High psi equals lost HP. I thought the objective was just enough oil to lube bearings, cool bearings, pump hyd lifters if you have them, feed oil to rockers...
 
autoxcuda said:
Why would a motor need 75 psi at cruise. High psi equals lost HP. I thought the objective was just enough oil to lube bearings, cool bearings, pump hyd lifters if you have them, feed oil to rockers...
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In testing (actual testing) the difference between 70 psi and 50 psi oil pressure is 5 HP on a good day. That is it.

Now here is a real bender. We have lowered oil pressure and LOST HP...sometimes as much as 12-15. So to just say someone has too much oil pressure is incorrect. I will tell you I don't like any Chrysler V-8 to have less than 40 psi HOT idle and IDC if it's 100 at WOT. It won't hurt a thing.

There are piles of scrapped rockers and shafts because of low oil pressure and because guys want to spin them up and not INCREASE oil to the top end. Chrylser oil timing (for the mains and the rockers) is fairly straight forward but has quirks. Maybe I should write a sticky of what to do and not do because I see mostly incorrect stuff i.e. putting that stupid crossover tube in the lifter valley (waste of time...at best does nothing...worst case..decreases oil at the mains) and not increasing the diameter of ALL oil feed holes.
 
Just a quick FYI to all those reading the thread in the OP...540RAT was tossed from speedtalk for posting crap results. His testing procedure was proven false and that he wasn't even using the correct procedure to test engine oils.

If you want to learn about engine oils call Torco Racing oils or Joe Gibbs. Be very careful waht you read online. Verify EVERYTHING (especially if it comes from me).
 
I think it would be interesting to learn the actual chemical process behind some of this stuff, but I chose a route other than chemical engineering and am too lazy to learn much new :)

I am somewhat paranoid, perhaps for no real reason, of putting additives in the oil since I make the assumption (maybe a bad one) that the chemists at the oil companies put their blends together for a reason. Throwing in an additive may affect that blend.

I suspect there is more going on with the oil and camshaft interaction than just the phosphorous and zinc content, but I haven't done any independent research to look at this.

We do use zinc in one of the systems at work and I do know zinc has chemical properties similar to cobalt and will replace cobalt in the steel structure. Phosphorous is the lubricant, so maybe zinc forms a sacrificial layer in the steel that is continually replaced by the zinc in the fluid.
 
This is what I wanted. Food for thought. Not everything you read online is true. "I'm a French model! Wewe!" I agree Madscientist. I'll take all the oil pressure my filter will take. I'm not worried about 5 hp as much as longevity. Chevy's are known for lower pressures like I had. I've seen a lot of them not live long too. I still believe very strongly that flat tappets need zinc but probably not as much as you think. I was looking for something I could find local for a fair price and that's one of the factors that put me on Vr1. 20 50w Brad penn is probably fine but I have to order it online and it's about $9 a quart, which I would gladly pay if I thought it was better. But I don't it's that great. Criscbath, A lot of my friends use Vr1, rotella, or pennsoil. I had a good break with Brad penn and I have about 1000 miles on the engine. Do a little research and I'm sure you'll figure it out. I'm not big on additives. I've never used them except for Lucas.
 
I used the STP oil additive with zinc. I'll let you know how that goes
 
Excessive oil pressure not only loses HP (very small amounts) and could hurt a motor more than help it. Volume is more important than pressor hence why most of use use a HV oil pump over a HP or a HV&HP.

Oh and AMSOIL ZRod here...if this thread becomes another oil thread :)
 
charger426 said:
Excessive oil pressure not only loses HP (very small amounts) and could hurt a motor more than help it. Volume is more important than pressor hence why most of use use a HV oil pump over a HP or a HV&HP.

Oh and AMSOIL ZRod here...if this thread becomes another oil thread :)
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How does oil pressure hurt the engine? Who says what excessive? What testing have you done to prove this?

Just curious.
 
Ironically, the best solution to the zddp problem isn't more zinc, it's more steel:
312-P5249862_2.jpg
 
I would think anything over 85 psi at wot would be too much. I have a hv pump too. With hv comes more pressure. The oil pump itself has a bypass spring. Probably hard to have too much. I'm curios about this loosing horse power with more pressure. A lot of late model cars use light weight oils I wouldn't attempt. A difference in tolerance and design.
 
Another Amsoil user here. For zinc & phosporous I put 5w-20 Dominator in my race car but they have a wide variety to cover any application.

5 HP difference between oil viscosities is more than one may initially percieve. It's a gain throughout the operating range. Perhaps an applicable analogy would be comparing engine #1 that makes 5 HP more at it's peak to engine #2 that makes 5 HP less at peak rpm, but more up to that point than engine #1. (Area under the curve.) Engine #2 will likely be faster than #1.

Clearance and machining tolerances have an influence on what kind of viscosity, pressure and volume you need.
I use a standard volume/pressure pump!
 

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Madscientist, I've read a lot online about 540rat but not too much that is negative. If you have a link, post it. I would like to read it. I try to gather as much info as I can when I'm researching. I know that any testing done by anyone is only as good as the equipment and the unbiased opinion of the person doing it.
 
madscientist said:
As I said in another post 540RAT was exposed on SPEEDTALK and kicked off the site for bogus testing procedures etc.

Be careful what you read.
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Spot on, including the Isky roller lifter fiasco. 540Rats a dick.
I just don't see how difficult this is for some people.. Just buy a good oil with zinc in it.. simple..
If you can't manage to do a simple task like that, then you deserve every cam failure you ever get..
 
jos51700 said:
Ironically, the best solution to the zddp problem isn't more zinc, it's more steel:
312-P5249862_2.jpg
Click to expand...

As long as your lifter bores are the correct size and alignment... All good until the needle rollers fail from poor alignment etc.. Somehow , up to a certain application, I think it's cheaper to purchase good oil, than it is to buy expensive roller lifters.
 
Hey I just came across it. Dont know him from Adam, didnt know he was a fraud. Apparently some here know of him. Where is the Speedtalk article? Seemed like good reading( very long, though) and most of it makes sense. Someone tell me more!
 
Amsoil has always been high quality. 6 years ago, I was using 15 50w mobile 1 with a flat tappet cam after break in. After about 50 miles, I noticed a couple of lifters would tap for a few seconds on start up. I called lunati and the tech asked what oil I was using. When I told him, he said lunati didn't recommend using full synthetic oil on flat tappets until they were well broke in. I asked how long. He said 20000 miles! Not sure how true that was but as soon as I went to conventional oil. The problem went away. I use mobile on all my late models with out issue. I should probably quit being so cheap and go roller.
 
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