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Topic: Oil recommendation for LT-1?

in Forum: C3 Engines


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Oil recommendation for LT-1? (1/18)
 6/10/05 11:24am
SportivoGold Member
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San Pedro, CA - USA

Vette(s):
1971, LT-1, T-top, 4-speed (M21), Mulsanne Blue, 3.70 rear, mostly original (sidepipes). 2006, Daytona Sunset Orange Coupe.


Joined: 5/26/2005
Posts: 239

I'm quite the "dummy" when it comes to Corvettes (so far). My recently purchased 1971 LT-1 is my first Corvette (after 40+ years of lusting). I'm about to change oil for the first time, and wonder if synthetics (like Mobil 1) are OK for this type of high-performance engine, and if so, what specific formula. Any thoughts or recommendations from the C3VR membership?

 



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Oil recommendation for LT-1? (2/18)
 6/10/05 2:00pm
Silver69
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Joined: 1/26/2004
Posts: 313

[QUOTE=Sportivo]

I'm quite the "dummy" when it comes to Corvettes (so far). My recently purchased 1971 LT-1 is my first Corvette (after 40+ years of lusting). I'm about to change oil for the first time, and wonder if synthetics (like Mobil 1) are OK for this type of high-performance engine, and if so, what specific formula. Any thoughts or recommendations from the C3VR membership?

 

[/QUOTE]

Your only a dummy if you don't ask questions. I have heard that synthetic in an older engine may cuase some oil leaks. I just checked the owners manual and went by GM's recommendation on my BB for oil weight. I would go with a very good filter ( not the $3.98 kind) and a very good grade of oil. Do it yourself and save money and greif. Taking to a quik lube place may not be the best way to go. They make there money on lower grade products IMHO.

 

Anyway its good to get all oily once ina while.

Oil recommendation for LT-1? (3/18)
 6/10/05 2:09pm
SWestLT1
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Posts: 123

Silver69 is right...    take it from me!   I use a premium quality 10W-30 like Quaker State or one of the other top brands...   Invest in a good oil filter. I keep an Autolite on hand for shows where originality counts, but run a Fram on the street.

Congrats on your first purchase.. you picked a heck of a good car to start with.. hope it's documented and has a trackable history... There are quite a few LT1's on the C3VR pages!
Oil recommendation for LT-1? (4/18)
 6/10/05 2:26pm
jredding
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Miramar, FL - USA

Vette(s):
1972 coupe/350 cid/mild cam/4 spd/20 ft. paint (looks perfect from 20 ft.), but it sure runs nice.


Joined: 3/16/2004
Posts: 672

My 72 left a nice puddle of Redline synthetic after it's first oil change under my care. It's plenty hot down here in southern FL so I go with regular 10w-40 Valvoline. Last change I used a K&N Performance Gold filter (expensive sucker), but then again, I've been pampering this thing alot more than the "old lady" even. So what's a few bucks more.

JR

P.S. Redline synth sells for $7.98/Qt.

jredding38513.4774305556
Oil recommendation for LT-1? (5/18)
 6/10/05 3:15pm
knotacare
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Newark, DE - USA

Vette(s):
1968 Conv, 454HO,500HP-600TQ, TKO-600,3:70 HD rear,hotrod air, custom paint & suspension,1973 Ruby Red,T-top, 383 Stroker, TK)-500,frame off restro, 1967 Dodge Coronet, 340 stroker to 406, Dana 60


Joined: 7/26/2004
Posts: 463

Whatever oil you decide on try & stick to the same brand...don't be switching from one brand to another. I use Mobile 1 in 3 of my newer cars including the vette , but it's a fairly new engine. Mobile1 or others like it will cause leaks in older engines. As long as you change your oil & filter when the engines hot every 90 days or 3000miles whichever comes first with  good oil & filter you'lll be fine. Asking questions is the only way to learn & the more I ask the less I know.

Alan



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Oil recommendation for LT-1? (6/18)
 6/10/05 4:27pm
NorskyLifetime Member
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West Burke, VT - USA

Vette(s):
SOLD - "The Toy" - '70 Convertible
SOLD - "The Beast" - '90 ZR-1 (#682)
SOLD - "Betty" - '28 Ford Model A Tudor
Still have - "BLKBRRD" - '78 Pontiac Trans Am


Joined: 1/23/2002
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I've picked up from other threads that the synthetic oils have smaller and more uniform molecules along with a more aggressive detergent component. 

While the smaller molecules is a good thing, because they can get into tighter places than regular oil and lubricate better, it is a not so good thing because they will find, and exit through, gaps in gaskets easier. 

And while the detergent component is a good thing from the standpoint of keeping the engine parts a bit cleaner, in an older engine with some sludge buildup the detergent scrubs away the sludge allowing for the exiting issue mentioned above.

So if you know that all the gaskets have been changed out recently going with the synthetic oil will do a better job of lubricating and cleaning.  I've been blending (4 quarts regular and 1 quart synthetic of the same brand and weight of oil) for a couple of years and haven't noticed any measureable increase in the dripping or consumption.  When I get around to pulling the engine and going through it I'm planning on making the switch to all synthetic.



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Jim Olson 

"The Toys"...!!!  Save the Wave!

Where I've been in a Corvette...!!!

Oil recommendation for LT-1? (7/18)
 6/10/05 4:42pm
SportivoGold Member
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San Pedro, CA - USA

Vette(s):
1971, LT-1, T-top, 4-speed (M21), Mulsanne Blue, 3.70 rear, mostly original (sidepipes). 2006, Daytona Sunset Orange Coupe.


Joined: 5/26/2005
Posts: 239

Thanks to all for the great replies! It sounds like the common theme is quality, quality, quality.

I may go to my ol' stand by, Castrol Racing oil, which I used in my 289 high performance Mustang (alas, a Ford - but that was many moons ago). And the K&N filter idea sounds like a good one.

This is definitely a do-it-yourself job; no Jiffy-Lube for me!



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Oil recommendation for LT-1? (8/18)
 6/10/05 9:37pm
tricerLifetime Member
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SEVERN, MD - USA

Vette(s):
1970 LT-1 Convertible Bridgehampton Blue Metallic 1999 Convertible Nassau Blue Metallic


Joined: 9/30/2002
Posts: 453

The race shop that rebuilt my engine and my restoration shop both recommended 20-50 for my LT-1 - but to stay away from synthethics for the reasons mentioned above.
Oil recommendation for LT-1? (9/18)
 6/10/05 10:03pm
RADARB8Lifetime Member
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Montesano, WA - USA

Vette(s):
had a really nice one. sold it to a good friend. Purchased 2004 custom coupe in Feb. 2009 did not tell anyone here until August 2009. BAD I KNOW.


Joined: 9/27/2003
Posts: 1931

I have to pipe in here that I purchased my LT-1 about 21/2 years ago and the pervious owners were using mobil 1 15/50 one in the red cap.

And i have been only using that brand and grade since then.  I just and the intake gasket replaced and i have had no problems.

just my two cents, not worth that much either with inflation and all.

Heck i have no vette or any car knowledge either, thats one I began a lifer, lots of time to learn. Larry

Oil recommendation for LT-1? (10/18)
 6/22/05 2:36pm
pws69
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Posts: 15

[QUOTE=1BadLT1]

I have to pipe in here that I purchased my LT-1 about 21/2 years ago and the pervious owners were using mobil 1 15/50 one in the red cap.

And i have been only using that brand and grade since then.  I just and the intake gasket replaced and i have had no problems.

just my two cents, not worth that much either with inflation and all.

Heck i have no vette or any car knowledge either, thats one I began a lifer, lots of time to learn. Larry

[/QUOTE]



I have been using Mobil1 15W50 in my '69 350 for three years now and I am very pleased with it - good stuff.  Doesn't leak any more than the Dino did before it - but that's what happens when you use a cheap, chrome oil pan like the PO did. Going to be changed to a correct pan real soon now!!


pws6938525.4846875
Re: Oil recommendation for LT-1? (11/18)
 8/31/18 2:50pm
Rick2872
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Moorpark, CA - USA

Vette(s):
1972 Corvette - Deep Red with some pearl. 4 Spd with air.


Joined: 5/18/2018
Posts: 2

I have a '72 LT1 and I used Mobil 1 for the first oil change and yes, it did leak all over my garage.  Now I use a standard oil (Pennzoil) WITH an a Lucas oil additive that contains ZINC.  Older engines need to replace the zinc they used to get with leaded gasoline.  The additional zinc helps to protect the engine.
Re: Oil recommendation for LT-1? (12/18)
 8/31/18 7:56pm
F4GaryGold Member
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Grapevine, TX - USA

Vette(s):
1972 LT-1 convertible with factory air.


Joined: 8/26/2006
Posts: 1406

Rick2872 said: I have a '72 LT1 and I used Mobil 1 for the first oil change and yes, it did leak all over my garage.  Now I use a standard oil (Pennzoil) WITH an a Lucas oil additive that contains ZINC.  Older engines need to replace the zinc they used to get with leaded gasoline.  The additional zinc helps to protect the engine.

Dude, you responded to a 13 year old thread. LOL

I use Valvoline VR1 10w30 dino oil in my 72 LT-1.  You can order it at O'Rielly's and it has plenty of zinc in it.






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Re: Oil recommendation for LT-1? (13/18)
 9/7/18 1:36pm
nosal1
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Dunedin, FL - USA

Vette(s):
1980 Corvette Torch Red with Gold metallic 370HP/350 CU.IN.Turbo 350 w/shift kit.Originally CA.Car with 305 CU.IN.


Joined: 3/21/2006
Posts: 262

Hello All, If I may suggest that if you have a flat tappet cam/lifters you should consider using Shell Rotella T 15 x 40 oil or Chevron Delo 400 multigrade oil as these among other "diesel oil" lube carry an adequate amount of ZDDP to protect your rotating parts i.e Cam and Lifters..

Don't concern yourself of the diesel  designation,after all an engine does not know whether it is a diesel engine or gas!!

Late model  engines with roller cam/lifters do not require zddp as they haven't the friction normally with flat tappet parts.                            nosal1       Sal C

Re: Oil recommendation for LT-1? (14/18)
 9/15/18 12:30am
73shark
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Overland Park, KS - USA

Vette(s):
1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.


Joined: 7/9/2003
Posts: 864

They had to take the zinc out of the oil when they went to cats as it poisoned the cats.

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1973 L-82 4 spd

Re: Oil recommendation for LT-1? (15/18)
 9/15/18 9:55am
nosal1
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Dunedin, FL - USA

Vette(s):
1980 Corvette Torch Red with Gold metallic 370HP/350 CU.IN.Turbo 350 w/shift kit.Originally CA.Car with 305 CU.IN.


Joined: 3/21/2006
Posts: 262

The Gobernut made the oil companies do it because the zddp screwed up the CAT...The gobernut alsi is killing the engines as well with the E10,15,and 85 ethanol fuels.I have had to rebuild several carbs due to the attack of the ethanol on the rubber on pumps internal gaskets,and corrosion of the needle ,seats..

Ethanol is also attacking the rubber lines from tanks to fuel pumps,and any rubber lines in the fuel system..Q-Jet site has a alcohol/ethanol resistant fuel lines etc..The ethanol eats at the stock rubber line until it chews enough to plug inlet fuel filters..This is not a guess as I have been fighting a long time.
Good luck to all...                   nosal1              Sal C
Re: Oil recommendation for LT-1? (16/18)
 9/15/18 10:02am
nosal1
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Dunedin, FL - USA

Vette(s):
1980 Corvette Torch Red with Gold metallic 370HP/350 CU.IN.Turbo 350 w/shift kit.Originally CA.Car with 305 CU.IN.


Joined: 3/21/2006
Posts: 262

ZDDP values and High Zinc Oils

FYI FILE from Vette forum..

Most technically inclined gearheads understand the value of real world, motor oil “load carrying capacity/film strength” testing. The results show us how various oils compare when it comes to wear protection. And we can use that information to make an informed decision as to which oil we want to select for our engines.

Though, there are some folks who are extremely set in their beliefs about what they’ve always been told and read, regarding high zinc oils providing excellent wear protection. But, the truth is, like all things in life, motor oils are NOT all created equal. And some oils are simply better than others, no matter what their zinc levels are. Anyone would have to be delusional to think otherwise. And “Wear Testing”, RATHER THAN ZINC LEVELS ALONE, can show us how various oils stack up against each other regarding wear protection capability, as you will see in the real world test data below. 

Some folks, who REALLY believe the notion that more zinc in their oil will provide more wear protection, often throw a tizzy fit and get very nasty when test data shows a low zinc oilproviding better wear protection than a high zinc oil. But, the fact is, behavior like that will NOT change the facts regarding what oils provide excellent wear protection and what oils do not. However, to keep everyone’s blood pressure down this time, we’ll look at ONLY HIGH ZINC OILS here. That way, all the oils are on an even playing field. However, true zinc lovers will no doubt be disappointed, because not all high zinc oils tested well, even though they all have plenty of zinc. 

And keep in mind for comparison with the oils below, that earlier oil industry testing has found that above 1,400 ppm, ZDDP INCREASED long term wear, even though break-in wear was reduced. And it was also found that ZDDP above 2,000 ppm, started attacking the grain boundaries in the iron, resulting in camshaft spalling. So, no matter what zinc fans might “believe”, there is such a thing as "too much of a good thing".

The following group of 40 oils have zinc levels above 1100 ppm, and are ranked according to their “load carrying capacity/film strength”, or in other words, their “wear protection capability”, at230*F. The tests were repeated multiple times for each oil, and even though all the results for each oil were consistent within a few percent, those results were averaged to arrive at the most accurate and representative final psi numbers shown below. And every single oil was tested EXACTLY THE SAME, so they all had the same opportunity to perform as well as their chemical formulation would allow.

But, before we get into the ranking list of those 40 oils, let’s take a closer look at one of those oils in particular. The oil is:

10W40 Summit Racing Premium Racing Oil, API SL conventional 
The bottle makes some bold claims, such as:

* Double the zinc for superior flat tappet cam protection.

* The additive package contains 1800 ppm ZDDP, providing levels of protection unattainable from conventional motor oil. Provides excellent protection from metal to metal contact.

Problem is, this oil fell FAR SHORT of living up to that inflated boasting. These claims were obviously created by the Marketing Department with no regard for what this oil can actually do. This oil ranked a pathetic 85th out of the 94 new oils I’ve tested so far. And it ranked only 34th out of the 40 oils examined here. Once again, here is an oil with high levels of zinc that DID NOT help it perform very well, even among other high zinc oils. Buyer beware. Motor oils are among the worst products for false advertising.

Now let’s consider the claim on its bottle of 1800ppm ZDDP. Since Oil Companies typically don’t publish the ZDDP values of their oil, I sent this oil to Professional Lab, ALS Tribology in Sparks, Nevada, to see just what is really in it, and to see how that claim of 1800ppm ZDDP compares to reality. Here are the results that came back:

zinc = 1764 ppm
phos = 1974 ppm

NOTE: Most of the time, an oil’s zinc level is higher than its phos level, but the phos level here is greater than the zinc level. That is NOT a typo. That is how this oil’s results came back from the Lab. I’ve seen phos levels higher than zinc levels in approximately 40% of all the oils I’ve sent in for component level Lab Testing. So, it varies and just depends on a particular oil’s formulation. And the values listed below are all just the way they came back from the Lab.

If you average the zinc and phos values of this Summit Racing Oil, you come up with 1869 ppm. And that value is of course more than the 1800 ppm ZDDP claimed, so it appears they’ve averaged the values and then rounded down to the nearest 100 ppm, to be on the conservative side. 

And since the ZDDP values are not usually available for most oils, we’ll calculate the ZDDP values for all the oils below, in the same manner as this oil, which should get us very close, if not right on target. But, for quick and dirty mental calculations, you can just figure the ZDDP value as approximately half way between the zinc and phos levels.

Here’s the ranking list:

Wear protection reference categories are:

*** Over 90,000 psi = OUTSTANDING protection

*** 75,000 to 90,000 psi = GOOD protection

*** 60,000 to 75,000 psi = MODEST protection

*** Below 60,000 psi = UNDESIREABLE
The higher the psi number, the better the wear protection.

1. 10W30 Lucas Racing Only synthetic = 106,505 psi
zinc = 2642 ppm
phos = 3489 ppm
ZDDP= 3000 ppm
NOTE: This oil is suitable for short term racing use only, and is not suitable for street use.

2. 10W30 Valvoline NSL (Not Street Legal) Conventional Racing Oil = 103,846 psi 
zinc = 1669 ppm
phos = 1518 ppm
ZDDP = 1500 ppm
NOTE: Due to its very low TBN value, this oil is only suitable for short term racing use, and is not suitable for street use.

3. 10W30 Valvoline VR1 Conventional Racing Oil (silver bottle) = 103,505 psi 
zinc = 1472 ppm
phos = 1544 ppm
ZDDP = 1500 ppm

4. 10W30 Valvoline VR1 Synthetic Racing Oil, API SL (black bottle) = 101,139 psi 
zinc = 1180 ppm
phos = 1112 ppm
ZDDP = 1100 ppm

5. 30 wt Red Line Race Oil synthetic = 96,470 psi
zinc = 2207 ppm
phos = 2052 ppm
ZDDP = 2100 ppm
NOTE: This oil is suitable for short term racing use only, and is not suitable for street use.

6. 10W30 Amsoil Z-Rod Oil synthetic = 95,360 psi 
zinc = 1431 ppm
phos = 1441 ppm
ZDDP = 1400 ppm

7. 10W30 Quaker State Defy, API SL semi-synthetic = 90,226 psi
zinc = 1221 ppm
phos = 955 ppm
ZDDP = 1000 ppm

8. 10W30 Joe Gibbs HR4 Hotrod Oil synthetic = 86,270 psi 
zinc = 1247 ppm
phos = 1137 ppm
ZDDP = 1100 ppm

9. 15W40 RED LINE Diesel Oil synthetic, API CJ-4/CI-4 PLUS/CI-4/CF/CH-4/CF-4/SM/SL/SH/EO-O = 85,663 psi
zinc = 1615 ppm
phos = 1551 ppm
ZDDP = 1500 ppm

10. 5W30 Lucas API SM synthetic = 76,584 psi
zinc = 1134 ppm
phos = 666 ppm
ZDDP = 900 ppm

11. 5W50 Castrol Edge with Syntec API SN, synthetic, formerly Castrol Syntec, black bottle = 75,409 psi
zinc = 1252 ppm
phos = 1197 ppm
ZDDP = 1200 ppm

12. 5W30 Royal Purple XPR (Extreme Performance Racing) synthetic = 74,860 psi 
zinc = 1421 ppm
phos = 1338 ppm
ZDDP = 1300 ppm

13. 5W40 MOBIL 1 TURBO DIESEL TRUCK synthetic, API CJ-4, CI-4 Plus, CI-4, CH-4 and ACEA E7 = 74,312 psi 
zinc = 1211 ppm
phos = 1168 ppm
ZDDP = 1100 ppm

14. 15W40 CHEVRON DELO 400LE Diesel Oil, conventional, API CJ-4, CI-4 Plus, CH-4, CF-4,CF/SM, = 73,520 psi
zinc = 1519 ppm
phos = 1139 ppm
ZDDP = 1300 ppm

15. 15W40 MOBIL DELVAC 1300 SUPER Diesel Oil conventional, API CJ-4, CI-4 Plus, CI-4, CH-4/SM, SL = 73,300 psi
zinc = 1297 ppm
phos = 1944 ppm
ZDDP = 1600 ppm

16. 15W40 Farm Rated Heavy Duty Performance Diesel, CI-4, CH-4, CG-4, CF/SL, SJ (conventional) = 73,176 psi
zinc = 1325ppm
phos = 1234 ppm
ZDDP = 1200 ppm

17. 15W40 “NEW” SHELL ROTELLA Diesel Oil conventional, API CJ-4, CI-4 Plus, CH-4, CF-4,CF/SM = 72,022 psi
zinc = 1454 ppm
phos = 1062 ppm
ZDDP = 1200 ppm

18. 0W30 Brad Penn, Penn Grade 1 (semi-synthetic) = 71,377 psi
zinc = 1621 ppm
phos = 1437 ppm
ZDDP = 1500 ppm

19. 15W40 “OLD” SHELL ROTELLA T Diesel Oil conventional, API CI-4 PLUS, CI-4, CH-4,CG-4,CF-4,CF,SL, SJ, SH = 71,214 psi
zinc = 1171 ppm
phos = 1186 ppm
ZDDP = 1100 ppm

20. 10W30 Brad Penn, Penn Grade 1 (semi-synthetic) = 71,206 psi
zinc = 1557 ppm
phos = 1651 ppm
ZDDP = 1600 ppm

21. 15W50 Mobil 1, API SN synthetic = 70,235 psi
zinc = 1133 ppm
phos = 1,168 ppm
ZDDP = 1100 ppm

22. 30wt Edelbrock Break-In Oil conventional = 69,160 psi
zinc = 1545 ppm
phos = 1465 ppm
ZDDP = 1500 ppm

23. 10W40 Edelbrock synthetic = 68,603 psi
zinc = 1193 ppm
phos = 1146 ppm
ZDDP = 100 ppm

24. 15W40 LUCAS MAGNUM Diesel Oil, conventional, API CI-4,CH-4, CG-4, CF-4, CF/SL = 66,476 psi
zinc = 1441 ppm
phos = 1234 ppm
ZDDP = 1300 ppm

25. 10W30 Royal Purple HPS (High Performance Street) synthetic = 66,211 psi
zinc = 1774 ppm
phos = 1347 ppm
ZDDP = 1500 ppm

26. 10W40 Valvoline 4 Stroke Motorcycle Oil conventional, API SJ = 65,553 psi
zinc = 1154 ppm
phos = 1075 ppm
ZDDP = 1100 ppm

27. 5W30 Klotz Estorlin Racing Oil, API SL synthetic = 64,175 psi
zinc = 1765 ppm
phos = 2468 ppm
ZDDP = 2100 ppm

28. “ZDDPlus” added to Royal Purple 20W50, API SN, synthetic = 63,595 psi
zinc = 2436 ppm (up 1848 ppm)
phos = 2053 ppm (up 1356 ppm)
ZDDP = 2200 ppm
The amount of ZDDPlus added to the oil, was the exact amount the manufacturer called for on the bottle. And the resulting psi value here was 24% LOWER than this oil had BEFORE the ZDDPlus was added to it. Most major Oil Companies say to NEVER add anything to their oils, because adding anything will upset the carefully balanced additive package, and ruin the oil’s chemical composition. And that is precisely what we see here. Adding ZDDPlus SIGNIFICANTLY REDUCED this oil’s wear prevention capability. Just the opposite of what was promised. Buyer beware.

29. Royal Purple 10W30 Break-In Oil conventional = 62,931 psi
zinc = 1170 ppm
phos = 1039 ppm
ZDDP = 1100 ppm

30. 10W30 Lucas Hot Rod & Classic Hi-Performance Oil, conventional = 62,538 psi
zinc = 2116 ppm
phos = 1855 ppm
ZDDP = 1900 ppm

31. 10W30 Comp Cams Muscle Car & Street Rod Oil, synthetic blend = 60,413 psi
zinc = 1673 ppm
phos = 1114 ppm
ZDDP = 1300 ppm

32. 10W40 Torco TR-1 Racing Oil with MPZ conventional = 59,905 psi
zinc = 1456 ppm
phos = 1150 ppm
ZDDP = 1300 ppm

33. “ZDDPlus” added to O’Reilly (house brand) 5W30, API SN, conventional = 56,728 psi
zinc = 2711 ppm (up 1848 ppm)
phos = 2172 ppm (up 1356 ppm)
ZDDP = 2400 ppm
The amount of ZDDPlus added to the oil, was the exact amount the manufacturer called for on the bottle. And the resulting psi value here was 38% LOWER than this oil had BEFORE the ZDDPlus was added to it. Adding ZDDPlus SIGNIFICANTLY REDUCED this oil’s wear prevention capability. Just the opposite of what was promised. Buyer beware.

34. 10W40 Summit Racing Premium Racing Oil, API SL conventional = 59,483 psi
zinc = 1764 ppm
phos = 1974 ppm
Claimed ZDDP level on the bottle = 1800 ppm
NOTE: Summit discontinued this line of oil, as of spring of 2013.

35. “ZDDPlus” added to Motorcraft 5W30, API SN, synthetic = 56,243 psi
zinc = 2955 ppm (up 1848 ppm)
phos = 2114 ppm (up 1356 ppm)
ZDDP = 2500 ppm
The amount of ZDDPlus added to the oil, was the exact amount the manufacturer called for on the bottle. And the resulting psi value here was 12% LOWER than this oil had BEFORE the ZDDPlus was added to it. Adding ZDDPlus SIGNIFICANTLY REDUCED this oil’s wear prevention capability. Just the opposite of what was promised. Buyer beware.

36. “Edelbrock Zinc Additive” added to Royal Purple 5W30, API SN, synthetic = 54,044 psi
zinc = 1515 ppm (up 573 ppm)
phos = 1334 ppm (up 517 ppm)
ZDDP = 1400 ppm
The amount of Edelbrock Zinc Additive added to the oil, was the exact amount the manufacturer called for on the bottle. And the resulting psi value here was a whopping 36% LOWER than this oilhad BEFORE the Edelbrock Zinc Additive was added to it. Adding Edelbrock Zinc Additive SIGNIFICANTLY REDUCED this oil’s wear prevention capability. Just the opposite of what was promised. Buyer beware.

37. 10W30 Comp Cams Break-In Oil conventional = 51,749 psi
zinc = 3004 ppm
phos = 2613 ppm
ZDDP = 2800 ppm

38. “Edelbrock Zinc Additive” added to Lucas 5W30, API SN, conventional = 51,545 psi
zinc = 1565 ppm (up 573 ppm)
phos = 1277 ppm (up 517 ppm)
ZDDP = 1400 ppm
The amount of Edelbrock Zinc Additive added to the oil, was the exact amount the manufacturer called for on the bottle. And the resulting psi value here was a “breath taking” 44% LOWER than this oil had BEFORE the Edelbrock Zinc Additive was added to it. Adding Edelbrock Zinc Additive SIGNIFICANTLY REDUCED this oil’s wear prevention capability. Just the opposite of what was promised. Buyer beware.

39. “Edelbrock Zinc Additive” added to Motorcraft 5W30, API SN, synthetic = 50,202 psi
zinc = 1680 ppm (up 573 ppm)
phos = 1275 ppm (up 517 ppm)
ZDDP = 1400 ppm
The amount of Edelbrock Zinc Additive added to the oil, was the exact amount the manufacturer called for on the bottle. And the resulting psi value here was 22% LOWER than this oil had BEFORE the Edelbrock Zinc Additive was added to it. Adding Edelbrock Zinc Additive SIGNIFICANTLY REDUCED this oil’s wear prevention capability. Just the opposite of what was promised. Buyer beware.

40. 30wt Lucas Break-In Oil conventional = 49,455 psi
zinc = 4483 ppm
phos = 3660 ppm
ZDDP = 4000 ppm

So, as you saw above, the highest ranking high zinc oil that provided the BEST WEAR PROTECTION of this group of 40 high zinc oils, had 3000 ppm ZDDP. But, the lowest ranking high zinc oil had one third MORE ZDDP at 4000 ppm. Even though this lowest ranked oil had far more zinc in it, it provided LESS THAN HALF AS MUCH WEAR PROTECTION, making it by far the worst of all 40 oils tested. Then the 4th place oil had only 1100 ppm ZDDP, and the 7th place oil had only 1000 ppm ZDDP.

So, the results above show 2 distinct things:

1. My tester and test procedure have no problem at all showing excellent performing high zinc oils. Therefore, no one can justifiably argue that my testing somehow works against high zinc oils. The absolute fact is, my oil testing performs worst case torture testing on motor oil. So, an oilHAS TO BE GOOD to produce good results. And we saw many high zinc oils with excellent results here. So, when the naysayers slam the value of my testing, they’re also saying at the same time, that high zinc oils are no good, since my testing shows excellent high zinc oils to provide excellent protection. They can’t have it both ways.

2. This is ABSOLUTE PROOF that not all high zinc oils have equal wear protection capabilities, which is the whole point I’ve been making for well over a year now. And why would anyone think that all high zinc oils are good? Not all tires are good. Not all cylinder heads are good. Not all camshafts are good. The world just doesn’t work that way. Some high zinc oils are quite good and provide excellent wear protection, while other high zinc oils are not good at all, and provide rather poor wear protection. It just depends on the particular oil in question. And that makes it totally clear here, that you simply CANNOT predict an oil’s wear protection capability by looking only at its zinc level. Life is just NOT that simple. If you only look at zinc levels, that is no better than guessing. So, if anyone tells you that you need high levels of zinc for more wear protection, even if it comes from a Cam Company, don’t believe a word of it. Because as you can see above, they have no idea what they are talking about. Would you really want to use the 40th ranked last place oil simply because it has more zinc than the number one ranked oil here? That is just what you’d be doing if you believed the incorrect advice about only looking at zinc levels. The ONLY way to know for sure how much wear protection any given oil can provide, is to look at “dynamic wear testing under load” results, such as I have provided above.

My oil testing data is very similar in concept to dyno testing an engine. An engine dyno test is also dynamic testing under load. For the guys who just want to look at a motor oil zinc level reference chart, that is like looking at an engine’s build sheet instead of its dyno print out. You can decide for yourself which provides more meaningful information.
Re: Oil recommendation for LT-1? (17/18)
 9/15/18 10:22am
F4GaryGold Member
Gold Member
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Grapevine, TX - USA

Vette(s):
1972 LT-1 convertible with factory air.


Joined: 8/26/2006
Posts: 1406

Check #3 on that list.

By the way, that list was compiled by 540Vette on the CorvetteForum and you can find that list there too.


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Re: Oil recommendation for LT-1? (18/18)
 10/30/19 12:08pm
TechdocwriterGold Member
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East Peoria, IL - USA

Vette(s):
1975 Bright Blue T-Top


Joined: 9/29/2005
Posts: 12

My first Corvette was a 1971 LT1 and I ordered the car. Still had solid lifters in it that year so I had them adjusted periodically. They had a great mechanic that worked on the Corvettes including mine. I asked him the same question about the recommended oil. He told me back then to run Valvoline SAE 30 wt detergent so I did. This was long before the synthetics were introduced. I still run Valvoline 10W30 in my 75 that we purchased new. I rebuilt that engine and breathed a little bit more HP into it than GM did. 



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