2.93 posi in a 8.2 diff?

Discussion in 'Got gears?' started by VET, Oct 6, 2023.

  1. rkammer

    rkammer Gold Level Contributor

    What's "Evan coolant"?
  2. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    rkammer likes this.
  3. VET

    VET Navy Vet, Founders Club

    Here is write-up on this product. Even endorsed by NHRA.
    One of the forum members recommended it to me. My shop knew all about Evans and they highly recommended it too.

    Evans Waterless Coolant High Performance Coolant is a proprietary fluid with a specially-formulated inhibitor package designed for all gasoline, light-duty diesel, LP, and CNG engines. Evans is now NHRA track approved! It contains no silicates or phosphates and requires no supplemental coolant additives. This coolant has a boiling point of 375 degrees F and will not vaporize--eliminating overheating, boil-over, and after-boil. The low vapor pressure reduces stress on the engine cooling system components. Evans Waterless Coolant High Performance Coolant will also eliminate corrosion and electrolysis, and offers permanent protection to temperatures as low as -40 degrees F.

    Another good write-up from a successful race team that helps explain how Evans helps.

    When coolant boils in the radiator, that is a sign that the coolant is saturated, and cannot absorb any more heat from the engine. If water is part of the engine coolant, the water will expand as it turns to steam which will force the coolant out of the radiator overflow.

    When that happens you lose coolant resulting in less coolant remaining in the cooling system to absorb the heat from the engine. With less coolant present to carry away the heat...the temperature of the coolant in the engine will continue to climb. That is when the physical damage can occur to the engine, Flathead Fords often developed cracks in the block when this occurred.

    The high boiling point of the Evans Coolant combined with the fact that it has minimal expansion even at the higher temperatures means that there is no coolant loss with the Evans Coolant. The Evans Coolant has the ability to absorb a much greater amount of heat from the engine as compared to a 50/50 antifreeze and water mixture.

    One thing you will notice with the Evans Coolant installed is that the in dash temperature gauge will read slightly higher. That is because the Evans Coolant is actually drawing more heat out of the engine block. If you check the engine block using an infrared temperature gun...you will see that the engine block is physically cooler than it was with the antifreeze and water mixture. Remember...the temperature gauge in the dash is reading the temperature of the coolant itself, and not the temperature of the engine block.

    You also need to remember that the antifreeze in a conventional antifreeze and water mixture does not directly benefit the engine cooling process. It is there to counteract the effects of water in the cooling system, to prevent rust and corrosion from forming that would eventually reduce or stop the flow of coolant through the radiator. To explain it another way...

    Antifreeze... is there to keep the inside of the cooling system clean and does nothing to directly benefit the removal of heat from the engine block. Water has that job. That is why when you add a coolant mixture greater than a 50/50 mix your antique vehicle. it overheats quicker. It is because there is less water present which is actually what draws the heat out of the engine. VET
  4. rkammer

    rkammer Gold Level Contributor

    I've just read over the Evan's Coolant info (thanks, Larry and VET). While my engine doesn't run hot I was especially interested in reading that:
    "Antifreeze... is there to keep the inside of the cooling system clean and does nothing to directly benefit the removal of heat from the engine block. Water has that job. That is why when you add a coolant mixture greater than a 50/50 mix your antique vehicle. it overheats quicker. It is because there is less water present which is actually what draws the heat out of the engine."

    So, does this mean if I run LESS than a 50/50 coolant mixture that my engine might run even cooler while idling with the A/C running during the summer because I have more water to cool the motor? (I obviously don't need antifreeze for cold weather protection here in Florida).
  5. VET

    VET Navy Vet, Founders Club

    From what I have read, for guys in the deep South, they run 70% water & 30% Glycol. VET
  6. monzaz

    monzaz Jim

    BAck to the posi -
    No Clutch units for the Buick till 1971
    Cone unit. only-
    I would like to see pics of the posi unit.... that would solve all the questions on this.
    Fabcraft got all the posi info from me...I was doing that conversion for years before the gears were made.

    I made a posi for the 3.23 and 3.42 unit
    and i make a unit for the 2.73 and 2.93 ratios also.
    I can mod a unit to fit the 2.56 ratio...BUT seems kind of moot point to make the 2.56 posi unless your doing a smokey burn out contest...LOL :D
    2.73 - 2.93 unit will be a Eaton unit clutch
    3.23 - 2.42 I use the Cone type unit
    I have made a few 3.64 - 5.00 Posi units from a modified eaton BUT it was a lot of welding and machining etc.
    Just not too much call for all this stuff since FABCRAFT pull the ring and pinion gear PLUG....
    JD Race
  7. monzaz

    monzaz Jim

    Oh and I have retro fit Chevy posi units into Buicks 8.5 into pontiac 8.2 rears in a pinch in the earlier years of when I started...JUST did not have the parts supply I do now... and knowledge etc. There is some Frankenstein stuff floating around out there from my early experimental years...lol.
    Max Damage likes this.
  8. Mark Demko

    Mark Demko Well-Known Member

    Yes it does, I mentioned that before in another post.
    I run just one gallon of antifreeze and the rest is water. I have a 30 year old 4 row copper brass radiator and my temp runs consistently 170, that’s with IIRC a 160 stat.
    68Buick-Jim likes this.
  9. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Anti freeze does not transfer heat as well as water. The more antifreeze you run percentage wise, the worse your heat transfer. There is a reason why the container says, no more than 70% concentration. I had a neighbor whose overheating problem in his Toyota Camry, we traced to the fact that he used the anti freeze full strength. Once we drained half out, and filled it with distilled water, the problem disappeared.

    The main purpose of anti freeze is freeze protection. It also contains anti corrosives and water pump lubrication additives. You can get that by using a product like Red Line Water Wetter and 100% distilled water. If you live in a climate that does not require freeze protection, you can maximize your heat transfer by doing so.

    68Buick-Jim and DaWildcat like this.
  10. BrianTrick

    BrianTrick Brian Trick

    This one if for my own car. 1970 Buick 8.2”,narrowed 1/2” on each end,FabCraft 3:64 gears that I bought in 2018,Tru Trac 30-spline unit,modified for this. This is going in my 70 GS 455 4-speed Stage2.

    Attached Files:

    12lives likes this.
  11. 12lives

    12lives Control the controllable, let the rest go

    That s why every jug of anti-freeze tells you the mix to use for the coldest temperature you will see. It does raise the boiling point too, so that helps, as does the correct radiator cap.
    "For every pound of pressure in a closed cooling system, the boiling point is raised by three degrees."
  12. gsjo

    gsjo Platinum Level Contributor

    Yes, it was a nice used unit,seems like somebody had there way here with a few things on this one.
  13. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    So VET is mistaken when he said it was a clutch unit?
  14. Ken Mild

    Ken Mild King of 18 Year Resto's

    What's funny is you say your high water temp is gone but the Evans site says that you're likely to see "higher" water temps reading on your gauge because it's doing a more efficient job extracting heat from your block. So this is very perplexing to me.
    Max Damage likes this.
  15. VET

    VET Navy Vet, Founders Club

    I think its a combination of all the factors.
    Evans coolant.
    New fan clutch.
    New high flow thermostat.
    New Aluminum Radiator.
    TA Performance, high performance water pump.
    Engine re-tuned.
    Addition of MSD ignition system.

    I will say, the biggest difference we saw in lowering the water temperature is the addition of the aluminum radiator.

    All the other components did help, the aluminum radiator was the biggest contributor in lowering the water temp. VET
  16. 12lives

    12lives Control the controllable, let the rest go

    Ken - It might depend on where the sensor is, but this is one of their tech responses: "Typically this application will run the same temperature or slightly hotter as 50/50 antifreeze. To decrease the operating temperature there must be improvements to the system. "
    It appears to me that there are many benefits to the Evans waterless coolant, but lowering the engine temp is not one of them.
  17. VET

    VET Navy Vet, Founders Club

    Thanks 12lives. I want to point out, this is my first experience with having high water temps.
    My first reaction is to do "everything" I can to cure this serious issue.
    I had just purchased this Buick GS 455 and had no idea I would be faced with this type of problem.
    I took advise from members on this forum and researched their recommendations.
    I started with less costly items at first.
    I should have started with the aluminum radiator first, like LarryGS70 recommended.
    I'am just glad i'am in a happy place now and i'am very happy I joined this forum where everyone helps out each other.
    This is my first BBB, so I have a lot to learn about these cars and their drivetrains.
    Thanks to everyone who helped me with this huge issue I was facing. VET (Navy)
    Ken Mild and 68Buick-Jim like this.
  18. 12lives

    12lives Control the controllable, let the rest go

    Now get some miles on it!
  19. VET

    VET Navy Vet, Founders Club

    You bet I will!!!!:D:)
  20. Mark Demko

    Mark Demko Well-Known Member

    I read IIRC years ago that waterless coolants had other benefits but better cooling wasn’t one of the MAIN or intended benefits.
    Straight water is the best coolant, but straight water has some drawbacks, corrosion protection is one of them if left in the block indefinitely.
    12lives likes this.

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