C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette

Any advatages in using original GM 6041-M oil

 
Old 02-23-2019, 03:27 AM
  #1  
Primoz
CF Senior Member
Thread Starter
 
Member Since: Jul 2012
Location: Slovenia, EU
Posts: 787
Thanked 74 Times in 55 Posts
2017 C3 of Year Finalist
Default Any advatages in using original GM 6041-M oil

Are there any advantages in using original GM 6041-M spec engine oil in my 71?
I found a company in Germany that produces engine oils for classic cars that conform to original specifications?
Here is the link to manufacturer:
https://www.rektol-klassik.de/produc...C.html&Liter=5
Primoz is offline  
Old 02-23-2019, 08:05 AM
  #2  
leadfoot4
CF Senior Member
 
leadfoot4's Avatar
 
Member Since: May 2001
Location: Western NY
Posts: 57,926
Thanked 401 Times in 370 Posts
Default

If the engine in your '71 is the original engine, or one that is similar to the original engine, it has what's known as a "flat tappet" camshaft, as opposed to a "roller" camshaft. The interface between the bottoms of the "flat" lifters (tappets), is an area of high friction. The oils originally used in these engines was fortified with a Zinc Phosphorous additive (ZDPP), in order to provide adequate lubrication at the cam/lifter interface. This isn't an issue with newer cars, as most cars manufactured after 1987-88, have had roller camshafts.

A few years ago, the US's environmental protection people decided that this oil additive contributed to the shortening of the useful life of catalytic converters. They also felt that there weren't enough cars on the road any longer, that needed the protection of the ZDPP additive. Personally, I think that's a load of BS, as there are still a LOT of older cars on the road. Nonetheless, they required the American oil suppliers to cut back/eliminate on the amount of ZDPP they put in the motor oils of today. While that will be more or less OK for current engines, it is definitely NOT OK for older engines. The lack of the zinc additive will drastically shorten the life of your camshaft, as well as circulate all of that ground up metal through your engine.
leadfoot4 is offline  
Old 02-23-2019, 08:34 AM
  #3  
jb78L-82
CF Senior Member
 
jb78L-82's Avatar
 
Member Since: Oct 2007
Location: Rhode Island
Posts: 6,248
Thanked 427 Times in 382 Posts
Default

The short answer is that you should use a gasoline oil with the proper amount of ZDDP additive. There are many gasoline oils sold here that have the proper amount of ZDDP. I would use one of them and skip buying one from Germany.
jb78L-82 is offline  
Old 02-23-2019, 08:39 AM
  #4  
Primoz
CF Senior Member
Thread Starter
 
Member Since: Jul 2012
Location: Slovenia, EU
Posts: 787
Thanked 74 Times in 55 Posts
2017 C3 of Year Finalist
Default

Originally Posted by jb78L-82 View Post
The short answer is that you should use a gasoline oil with the proper amount of ZDDP additive. There are many gasoline oils sold here that have the proper amount of ZDDP. I would use one of them and skip buying one from Germany.
Thanks! I live in Europe and buying from Germany is easy and shipping is like $15! Amsoil z-rod is twice the price!
Primoz is offline  
Old 02-23-2019, 01:12 PM
  #5  
Rotonda
CF Senior Member
 
Rotonda's Avatar
 
Member Since: Sep 2006
Location: Rotonda FL
Posts: 1,046
Thanked 76 Times in 70 Posts
Default

Two separate responses to your question.
1) I do not, and no one who has yet responded has any real knowledge of the properties of motor oils required in the EU and can only provide an opinion.
2) Having said that, there has been a great deal of progress (most of it very beneficial - see discussion of zinc phosphate above for a minus) made in the last 40-50 years (since 1971). I suggest you take advantage of this progress, and use a modern oil with the requisite amount of zinc phosphate. Unless your engine is on the ragged edge of needing a rebuild (new gaskets and seals, etc) it will cause your engine no harm and may help with reduced friction/wear.

FWIW - continue to use the viscosity recommended. Also, some owners recommend against synthetic oils in higher mileage engines - they claim it penetrates into very small spaces and causes oil leaks (Many others have not experienced this). I would be on the safe side and continue to use petroleum derived oils.
Rotonda is offline  
Old 02-23-2019, 01:20 PM
  #6  
Primoz
CF Senior Member
Thread Starter
 
Member Since: Jul 2012
Location: Slovenia, EU
Posts: 787
Thanked 74 Times in 55 Posts
2017 C3 of Year Finalist
Default

Use 10w-30 as per owners manual? Although the owners manual suggest using other viscosity for higher or lower temperature climates.
I like to use 10w-40 as in the summer it gets quite hot wherre I live.
Primoz is offline  
Old 02-23-2019, 04:02 PM
  #7  
7T1vette
CF Senior Member
 
7T1vette's Avatar
 
Member Since: Jan 2006
Location: Crossville TN
Posts: 30,363
Thanked 1,006 Times in 910 Posts
Default

Short answer is "No." Modern oils are much better than what was specified 40 years ago. And counter to most folks perspective, full synthetic oils are SO MUCH better at minimizing wear and maximizing engine life, we would be fools not to use them. That said, most full synthetics do not come with enough zinc for high performance solid lifter, flat-tappet cam engines, so you would need some additive. But, if you have a stock hydraulic lifter engine and don't run the poop out of it all the time, full synthetics off the shelf are perfectly fine.

P.S. More leaks occur when you switch to full synthetic oils because the molecular size of synthetic oil is much smaller than for organic oils. If the seals are worn enough, synthetics will leak sooner. But, it's just letting you know that the seals are worn and need to be replaced.

Last edited by 7T1vette; 02-23-2019 at 04:03 PM.
7T1vette is offline  
The Following User Says Thank You to 7T1vette For This Useful Post:
Primoz (02-23-2019)
 


Thread Tools
Search this Thread
Quick Reply: Any advatages in using original GM 6041-M oil


Sponsored Ads
Vendor Directory

Contact Us - About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: