roadkill2

Can't actually answer that with a concrete answer. However, zinc is a basic metal that provides the primary "lubricity" to Oil.

The bearings in an internal combustion engine normally are of bi-metallic construction, one of the base metals being Zinc. And zinc is very malleable, from molecular size through cast or forged shapings . . So at the molecular scale, it provides that malleable "cushion" between two dissimular metals . .

I've been told by engineers and a lot of people a lot smarter than me that oil isn't much of a lubricant, but a vehicle for the compounds and metals that ARE the true lubricants, and in our street engines, it's also the vehicle for the detergents that are used to continually wash the bearing surfaces clean.

That being the case, I would assume that unless the zinc content became so dense it would separate from it's vehicle and break down from it's original compound(s), there's probably never "Too Much" . .

Kind of like the discussion or argument over what is the ideal oil pressure?

On the "Oil Pressure" thing, I believe that if you have 25-30 PSI at the front main* through your RPM Range, you're good . . . everything's getting oiled. Others believe differently . .

*assuming your crank oils from the rear

Any Lubrication Engineers out there to discuss or refute the subject?

And . . On the subject of Alcohol breaking down the oil (Whatever one you're using). Alcohol is a aromatic solvent that doesn't dissolve readily in a hydrocarbon Fuel so while gasoline is mixed readily with oil, alky doesn't as well. Alcohol compounds, either Methanol or Ethanol tend to attach more readily to water molecules and in the process "Clump" into bubbles, which is not good in a system of oil being forced through close bearing surfaces at high speed . .

An oil ideally suited for alcohol will be one that can absorb or mix the alcohol and evaporate it through the operating cycle. Back in my "Nitro days" we watched really close for fuel in the oil because nitro doesn't mix well with oil either, and usually changed oil after every round. During my TAD Tuning days, we generally used Valvoline 50 racing oil and (Again) changed oil every round.

Currently, the Boss just put the "Grape Ape" on Alcohol and we'll see how that works. We haven't raced the car yet but it's been run several times and built engine heat in it, with cooling cycles in between. So far, the Amsoil looks fine . . We'll have more information on this by the end of April (I hope) . .

curtisreed

Remember also that oil is not just a lubricant but a coolant also when you start thinking about the weight of oil.

Go to this link and do some reading. There is a lot of good info here. Check out some of the article and tech items on the left side of the page.

http://www.drivenracingoil.com/dro/zinc-vs-detergent

From what I have gathered on the Brad Penn oil, the amount of ZDDP in the racing oil hasn't been decreased. Just their high performance street oils.

http://www.penngrade1.com/CMSFiles/F..._BRAD_PENN.pdf

I have used the Amsoil Dominator racing oil, running Methanol and have been very happy with it myself.

Curtis

hammertime

http://www.blackstone-labs.com/

zipper06

This is an intresting link, while i don't have a clue to the right answer on Zinc, i would challange any oil manfacturer to put their oil on a flat tappet cam .550 to .600 lift without zinc addative with 125/130 lbs of spring pressure in a racing application.
I agree that oil is more of a coolant than lubericant on the bearings it's a different story when it comes to cams and lifters.
The car manufacturers saw all this comming and changed to hydraulic roller lifters in the early 90's.
I know people running sprint cars that rules dictate flat tappets and the biggest problem they have is balancing spring pressure to make the cams and lifter survive and still run decent RPM's. I've seen flat tappet cams go bad on the startup with 125 lbs spring pressure, and the cam people all say not our problem.
I don't know how many people have seen the oil drained from a Nitro car or TF car, but it looks like it came from a mud hole.
On my end i don't run a vacuume pump, and there's alway some oil deluting with alcohol even with the best tune up and warm up. I gave up on the $8.00 to $12.00 a qt oil a few yrs ago and started useing shelf oil 20/50 and change it evry week between races. I do run lot's of clearance on rod and mains, .0025/.0035 and high volume pumps. I agree with Hammer on the oil pressure my oil pressure runs as low as 25/30 lbs on idle and almost never over 50 lbs at 7,000 rpms after everything is warmed to about 200 degrees. When i lived in Phx a number of yrs ago i knew a guy who ran a V6 dragster and only had 20/25 lbs oil pressure when i questioned him he told me oil pressure robs HP and he said it was never over 20 lbs in the traps, he did run mid 8's with the dragster. I haven't lost a bearing in yrs. but my cam went flat in my street El Camino afer an oil change last yr. in the 10 yr old enginge, and i rarly drove it.


O'h back in the old days when STP was king and they were sponsering Indy cars, they showed pit crews pouring in STP what they didn't show was the oil plug out and drain pan under the engine. :lol:

JMO

Zip.

roadkill2

I've found it interesting that there are so many opinions on oil and oil pressure. And, even more interesting is the fact(s) that one size doeasn't fit all, so to speak. There really doesn't seem to be many absolutes other than you gotta have oil and oil pressure.

What kind and how much depends upon the user as much as the use, I think.

Also what we do with the engine we put the oil in has a lot to do with what kind, etc. A drag race motor is subject to acelleration loading but not a lot of heat generation (if it's done right). It's also pretty much a one way loaded crankshaft assembly, not being subject to much decelleration or "back loading" on the bearings. So it shouldn't require as much care and feeding as a sprint car or oval track engine, one would think.

99% of the engine failures that I've experienced in drag racing started someplace else, usually a valve train failure or a piston failure (or contact) and then migrated to the crankshaft. I don't think I can look back and see an engine failure that I could contribute specifically to the oil I was using at the time or in particular, an oil pressure loss.

And, I'd bet that most, if not all of you guys here will look back and say the same. Of course there are and always will be exceptions.

The roundy round guys at NASCAR and most of the other oval guys using the Gen III and IV engines are running Joe Gibbs Oil, Amsoil or another zinc loaded synthetic at 0-20 weights . . 8800 to 9300 rpm, on and off the throttle, 300-500 miles and making them live (for the most part). Now they need oil to be a coolant, a lubricant and still suffer no parasitic HP loss in the process of pumping it through a high RPM engine. And they're also using "Sunoco Racing Fuel", which, as of last year, is ETHANOL.

That's a lot more than we Drag racers are asking or needing . . so we ought to be able to get by with murder, and I think a lot of us do . . Just dunno which ones, heh, heh . .

TheRabbit

And a bunch of us rednecks in the south that know about it! lol

It's what I use and it's GOOD STUFF and a LOT CHEAPER than any other oil of it's quality.

hammertime

TheRabbit

For some reason Blackstone lab couldn't figure out how to test oil the same as other labs. They had some kind if hard on for Brad Penn oil and tried to show lower specs / poor results of it's oils. Good thing their results were not given any credit. Way to many racers run Brad Penn oil for it not to be a good quality oil.

Nothing you can buy off the shelf has the levels of Zinc and Phosphorus as Brad Penn. The EPA has slowly worked on all off the shelf oils (including Rotella which many people use) to lower the levels of phosphorous. See note below from Brad Pen web site.

http://www.penngrade1.com/Zinc.aspx

hammertime

I like that their "in house" shows higher zinc then a neutral test lab

A few quotes straight from a big name lifter company last week on which oil to run .. "avoid any newer brad penn as the zinc is down considerably from it once was" .. followed by "if it says lucas oil on it .. its junk" . This call was after my engine builder suggested staying away from Brad Penn for lifter & cam life.

He was not a huge fan of vr1 (silver bottle) either unless you used cam shield Blackstone results of zinc 1300-1500ppm. Schaeffer was suggested which Blackstone found to be 1700-1900 ppm.

Here is another lab .. id love to see results of Brad Penn there if someone wants to send theirs in

http://www.polarislabs.com/

carry on oil is just oil anyways

TheRabbit

Again the myth about the zinc being down in Brad Penn oil was not true and that was a rumor started several years ago.

Have you looked at the zinc additive that they sell in parts stores? I read the entire back of it and even it doesn't have ANY zinc in it. lol
It's a blend of products that are suppose to "resemble" and preform like zinc.