Author Topic: What weight of oil??  (Read 1577 times)

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Offline nes-cv23

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What weight of oil??
« on: August 21, 2022, 05:43:31 PM »
What weight of oil would you guys recommend for a older 350 olds or chev ?      10w-30? 10w-40? I?ve heard of marine 25w-40?.
  Mine are getting old and I want to make sure they last as long as they can?   I?ve been running 10w-40, but I think I?d like to run something thicker? other than some honey style oil additives?
84 ssv-151, 76 cvx-16 ss, 77cvx-20 jet, 90 CSS-19, 78 cv-23, 77 gt-150, 2-78 cvx-16, 79cvx-16, 79 cvz-18,  73 cv-16, 74 cv-18, 89 219 Futura, 76 gt-150 jet, 79 cv-23, 02 Gx-225,  1980 intimidator = done!.. 79 hvp175   Now  done?

Offline thedeuceman

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Re: What weight of oil??
« Reply #1 on: August 21, 2022, 06:57:35 PM »
I run 20-50 diesel oil in my old stuff


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Offline carlsoncvx18

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Re: What weight of oil??
« Reply #2 on: August 21, 2022, 07:40:31 PM »
Ran rotella in my cvx18 since it was broken in. 
1987 CVX18.     1968 Glastron alpha sail boat
1977 GT150
1986 CV23
1984 Intimiadator
1981 CV27
1969 V-180 fundeck

Offline Plugcheck

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Re: What weight of oil??
« Reply #3 on: August 21, 2022, 09:47:16 PM »
As it pertains to marine engines only, I tend to favor lower viscosity 10w30 since boats rarely see the high temperatures that car engines do.   Blended or full synthetics have some impressive figures, but overall I've found synthetics to "seep" a bit more as they are molecularly smaller.    A straight 30 has some advantages as well, and for limited temp span engines in marine applications.    High mileage oils have additives that tend to keep seals from leaking, works great in auto applications, but honestly never ran them in boats much.    Pretty certain someone on the interweb has done more exhaustive studies related to oil.  Curious to know what others results have been.
Michael
1979 CVZ-18 388 CI Vortec Mouse
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2002 Bennington 2275CC 90 Mercury
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Offline still_fishin

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Re: What weight of oil??
« Reply #4 on: August 21, 2022, 11:13:27 PM »
I run 10-30 valvoline vr1 in both mine. 
'80 Intimidator
'85 CV23

Offline cv-19

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Re: What weight of oil??
« Reply #5 on: August 22, 2022, 07:59:58 AM »

  The newer oils have less zinc than they use to . About 1200 ppm is
 good level for older engines . Standard 10-30    10-40 oils are much lower.
  The Valvoline VR1 oil is a good choice and the Diesel oils have the higher zinc.
  Mobil 1 15-50 syn. has a higher level than most other syn. just under 1200 ppm.
  I know thats not the Question you asked, but something you should know when
  making an choice.

Offline ford-bldr

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Re: What weight of oil??
« Reply #6 on: September 07, 2022, 05:55:08 AM »
Caveat: People are "Loyal to their Oil" so everybody's opinion matters... to them.
So listen to whatever you want.

First off let me qualify myself. 9 years selling Specialized Lubes to Industrial Accounts.

That only means that my opinion only matters as much as anyone else with a keyboard.

Plugcheck, still_fishin and CV-19 are in the right ballpark.

If it doesn't have a catalytic converter in it then run racing oils.
Higher zinc makes your motor last longer - Cam life goes way up.

I'll try to keep it simple...

Off the shelves additives are just that - Additives. Put in a quart of "oil stabilizer" goo in and it gives you 1 quart less of lubricating oil.
Think about that....
Think about this... Remember how that stuff pours? Your oil filter is full of that stuff and the oil is running "bypass" right around that filter until you warm up.

Good Blends are the best of both worlds.
Synthetics don't like additives (Detergents etc) but run forever. Dino juices like additives and dissipate heat better.
Remember the saying "Oil cools as much as it lubricates". ?

That being said, Boats and old cars would benefit from running Racing Oil.
Higher zinc is where it's at. Shaeffers has a higher zinc content than anyone. See the links and make your choice.

People ran Rotella because it had a higher zinc content. No more. The Government put a stop to that.
So far they've left the racing oils alone.

Oh by the way, just because it says synthetic doesn't mean it's better anymore. New technology has given us a slew of junk synthetics that are not any better than the "Blue Bottle Big Box stuff.

https://crateinsider.com/content/HRE-Oil-Test-Dyno-Charts.pdf

https://crateinsider.com/oil-testing-data-by-hendren-racing-engines/


Dan



« Last Edit: September 13, 2022, 06:16:07 PM by ford-bldr »
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