Downdraft

what grade oil should I use in the 327 300? Ditto for the 4 speed.

Thanks.

Alex

67vetteal

Rotella Diesel 10/30. Amsoil Gear Oil. Al W.

fuelie65

Why diesel...for the detergent properties ???

babbah

I use diesel in my big block - I run Delo 400 15-40W
It has the zinc additive you need for valvetrain lubrication on our older motors.
Search the forum there are tons of articles on this, thats why I switched...The conventional oils have reduced amounts of Zinc additive these days.

orono64

I just had the valves done (again) and installed a new cam (again) in my 66 vert. This time I went to the most respected engine builder in my area $$$. He said some of my ongoing valve train problems have been because I was using the wrong oil. He suggested Valvoline Race oil or Delo for the same reason. I always thought if you bought a good grade of oil, it was only the weight to consider. I was told that multi-grade oils with wide ranges like 20-50 had more fillers to create that range which reduced the overall lubrication. Now I have to worry about Zinc.....

babbah

I have 2 friends that have stock 67 BB's and from out of nowhere they have lost complete lobes on thier cams ( and I mean the lobes were completely gone and the lifter base was worn round instead of being flat). They have been running these cams originally for decades.......Its got to be the oil....Thats when I learned of the zinc decrese situation.

I may add that before I swithced over to Delo 400 I had been running Valvoline 20-50- racing oil. I'm not sure if the amount of zinc in has been reduced in this type, does anyone know?

My highly modified 427/435 aluminum heads running original 11:00 CR has a solid lifter cam - No problems with the Delo either.

Donald #31176

According to SWCDuke the only consideration for vintage engine use is the API rating and viscosity. CI-4+ has the highest ZDDP additive package. CJ-4 has a reduced ZDDP package (about 13% less than Ci-4+) and SM a greatly reduced ZDDP package and NOT recommended for vintage engine use.

15W-40 weight oil is OK to about 10* F as a starting temparature. 10W-30 and 5W-40 CI-4 can also be had and can be used where a lower start temp is antiscipated.

CI-4+ is slated to be available up to 2010 but you might have to get it at a truck supply house.

babbah

Don - What is SM?
So should I continue to use the new CJ-4 diesiel oils vs anything else? Or should I go back to Val racing oil?

Is the diesel oil still the best way to go for the most amout of zinc?

Donald #31176

Babah,
The API rating is on the bottle of oil. Its usually a donut shaped symbol that states the rating. SM rated oil is the latest oil for gas ignition type engines. Because newer engines use roller type valvetrains and have sensors that are degraded by ZDDP, SM oil have a greatly reduced amount of ZDDP. I dont know what Valvoline Race oil is rated. The easist thing to do is get CI-4+ which has the highest amount of ZDDP and select a viscosity that is OK for the lowest antisipated starting temp.

cookie_monster

Saw this post, went into the garage to read my oil bottles. I changed my oil last weekend and used Chevron's 10-30 with a service rating SM. So, should I wait until my next oil change or drain this out now? What would you guys do?

devildog

Go to babbah's thread about oil that he started today, I put some info about gasoline-diesel-motor oil-ZDP there.

Most important: use a good quality Diesel engine oil and change it at least once a year...don't worry more than that about it. But, if you are interested, here are the issues about Zinc and multi-viscosity (10-30).

First, multi-viscosity vs straight grade. Generally, straight grade such as 30 is marginally better to use than 10W-30 as example. The reason being about 15-20% of the volume is a VI (viscosity index) improver. VIs are synthetic organic polymers (polyalfaolefins) that makes the motor react like 10 viscosity at low temps and like 30 vis at operating temps.

Reason to use multi-vis is mainly makes cranking and starting easier at low temps, and marginally reduces starting wear on parts. If your Corvette sets outside in the winter cold at temps less than freezing, and you do not let it warm up before WOT, use a multi-viscosity. If it is in a garage and you let is warm up a bit before lighting up the tires, use the straight grade like at 30...it has more lubricating without the VI. The VI is not as good as lubricating fluid as oil...I did NOT say the VI was bad!

(if your C-1 or C-2 Corvette sets outside in the freezing winter temps, it is my duty to keep it in my Houston garage for you, and of course exercise it periodically).

Which grade? Look at the manual at what GM said, it is what GM and the motor oil R&D people jointly spend $millions to test and jointly recommend (that what I use to do). They did not guess at it. But, in general use a lower vis, a 30 is better than a 50. Yes, the race guys talk about 50, 60 grade motor oil, but that is for many other reasons, but you aint racing (at least not all the time). They break them, bend them or just tear them down for inspect long before they wear them out. Many new engines require 5W-20 some even 0W, why...because they lubricate more precision tolerances better.

Zinc: This has become a new urban myth so beware. ZDP was/is an excellent additive for extreme pressure (EP) wear between two moving parts at great force (valve train parts). It was used in gasoline engines until Pt catalytic exhaust converters were mandated. Zinc destroyed the Pt effectiveness.

Non-zinc, non-metallic EP additives had been developed for diesel engine 20 year earlier BECAUSE diesel fuel has (had) sulfur which reacted with the Zn and produce bad stuff (ZnSO salts)in engines.

So the gasoline engine oil formulations were changed to this same diesel EP additve package...performs well just cost more than ZDP to achieve the same valve train protection.

Years ago when you rebuilt an engine or installed a new cam, the cam kit had a little jar of a white paste to rub on the cam lobes and lifters. This majic stuff was Zinc Oxide...same stuff your life gaurd or surfer rubed on his nose to look cool. Now days GM and the cam manufacturers do not ship the majic white stuff with the cam kit. They sell or tell you to go io GM and buy a pint or quart of a special make-up oil to coat the lobes and dump the remainder on top of oil galley. This special oil is a high concentration of these organic EP additives (developed 50 years ago for Diesel oil).

Now some ZDP is used in the modern Diesel oils...why? Less sulfur in the fuel; therefore, less risk of ZnSO corrosive salts. But, amounts of ZDDP in your crank case oil is PPM.

Many other EP additives also carry the burden of protecting the valve train. As long as the diesel oil has the high API service CI, CJ-4, etc. do not worry.

Remember why diesel oil? It has more of the additive than the gasoline oils.

Again, use a good high service Diesel oil, change it at least once a year, let them warm before you try to light up the tires, and then go drive em and have fun...don't worry about how many ppm of ZDP is in the oil.

Joe

mikem350

STP oil treatment (and their 1 qt Oil Stabilizer) state on the bottles that they contain ZDDP zinc. Easy crutch for peace of mind...

The $2 blue bottle stuff REALLY makes the oil thick, might not be what you need....

babbah

Devildog, Thanks for the response.
The reason I posted the original thread is because there are no more CI-4 oils on the shelves where im located, they are all CJ-4...

66 big block

if you use 10 w30 and add one qt of stp stabilzer with zddp is it the same as deisel oil?

Donald #31176

Because 90% of diesels on the road still use high sulfur fuel CI-4 will be available to the year 2010. If you cant find it at the usual auto parts places try looking for it at truck and farm equipment supply houses. The Walmarts around Maryland still carry CI-4.
Look for Delo400, Delvac, Castrol Techaire and Walmart brand Techline with the CI-4 API rating.

rongold

==================================
Go to Walmart, and buy their own brand of Super Tech Universal 15W-40 motor oil. It's made by Quaker State and still rated CI-4. All of the Shell Rotella and Delco Delo on the shelf were rated CJ-4 already. I just bought 6 gallons of the Super Tech last night.

C66 Racing

For those of you interested in a synthetic CI-4+ diesel oil in a 5w30, I'd recommend you consider this offering from AMSOIL:
AMSOIL Series 3000 Synthetic 5w30 Heavy Duty Diesel Oil

Its not cheap, but it is an excellent 30 weight CI-4+ diesel oil that isn't constrained by the new API SM autmotive and API CJ-4 diesel oil specifications. Anyone considering this oil would easily benefit from the AMSOIL Preferred Customer Program (link in my sig).