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Motor oil

Recommended motor oil for a 383

  • Conventional oil

    Votes: 2 18.2%
  • synthetic oil

    Votes: 6 54.5%
  • High mileage oil

    Votes: 1 9.1%
  • Other

    Votes: 0 0.0%
  • Synthetic blend oil

    Votes: 2 18.2%

  • Total voters
    11
  • Poll closed .
The reason I started this is because my 383 with a brand new rear main seal is still leaking. I am running synthetic oil 1030 in it. I’m thinking the synthetic oil is making it leak so I added Lucas oil leak stop seems to be working. Wondering if I should Switch to regular oil on my next oil change.
FYI I am using Supertech oil and Ive never had issues with it. citgo makes the oil which is really good. Lots of good reviews on it. By getting oils like mobile one or another name brand oil‘s you’re just paying for the name.
 
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I use Lucas Oli with Zinc. It’s their blend for muscle cars and hot rods.
 
my rear seal leaked with synthetic oil and stopped when I switched to conventional oil.
 
what do you recommend?
I voted synthetic, but...with "non-modern" engines, the cam shaft or engine manufacturer/builder may recommend a specific oil or ZDDP level.

Brand new 383 leaking rear main. If it was leaking before the rebuild and is now still leaking, either wrong seals, bad machining, warped/bent pan.
 
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The weight of the oil is going to affect the rear main seal leaking more than synthetic or not. The newer seals are a lip seal and should seal if installed correctly either way. I broke my motor in on Amsoil break in oil and am running a synthetic blend until the rings seat good and I have zero leaks.
 
What do you guys think about Lucas oil Stabilizer?
 
Nothing wrong with Super Tech. I've used it for years. It is a quality oil that is simply "sold by" Walmart.
P.S.
Their oil filters are also quality, made by Wix.

For what it's worth, I run Rotella T5 (synthetic blend) 10W30.
Run what YOU like.
 
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you do not need any of that Mouse Milk
the crap of the day changes every few years
STP
Winns
Lucas
Seafoam
 
Synthetic has nothing to do with leaks. If it leaks something is wrong. None of my engines using synthetic leak a drop.
Doug
 
https://mobiloil.com/~/media/amer/us/pvl/files/pdfs/mobil-1-oil-product-specs-guide.pdf

I just went down this path with the Mobil1 tech support person after I bought a couple of gallons of Mobil1 Turbo Diesel 5w40 which has plenty of phosphorus and Zinc and diesel oil is known to be a good detergent and a good wear additive package. Its a full synthetic oil, they do have a better pour point so in my opinion maybe they would be a little more prone to leaks. But if you leaks they are not going to get better, till you address them, its only a matter of time anyway.... Just my 2 cents...
 
yep syn oil is the best. amsoil is what i use in everything.your filters very important the micron levels of filtration is really what your also lookingfor out of the filters.i will say it again we spend thousands of dollars building the best of the best but when it comes to the oil we put whatever your dad used and his dad used. our engines are built with total different heat ranges, fuel etc.so you will put in your oil of your pick and then add a additive. something wrong with that picture if you have to add something to your brand new oil then its not the right oil. everyone worried about engine oil but when it comes to trans oil do you put a additive in it what about the diff some run 75-140 others run a straight 90 weight. do you add anything to these oils bet not. you run what you bought and change it when you think it needs it. of course you don't know what your oil is doing because oil sampling is not done. so how do you know how it's doing. use a syn oil and a high micron filter. remember oil is to protect your parts and idle time is worst on a engine than running a engine hard and fast.
 
gotta agree
I run wix filters and the 75-140 because I tow and live in the desert of so cal
those up north have to be careful about the xx-140
nothing changes
short trip usage is the toughest
I'm using 0w-40 eurospec oil mostly Iv-V synthetic
Windman's comments are most relevant to flat tappet sliding rocker motors for which the Corvair is a proxy
 
your a L.A driver. god bless you i hate driving over on those roads. but what a great test pattern for oil etc.
 
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