Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Need help from knowledgable engine builders

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by cpqtim, Sep 30, 2001.

  1. cpqtim

    cpqtim Registered Member

    Joined:
    Aug 25, 2000
    Posts:
    30
    Likes Received:
    0
    Location:
    Westport Ky.
    I placed the following post on offshoreonly.com. This is a site dedicated to high performance offshore boating. A marine engine will typically see extended periods of high rpm use. Oil temperatures are controlled by running seawater through a cooler, much like an air to air cooler only it uses water prior to entering the block. Cooling water flows through the block and is discharged with the exhaust gas. I posted this question but not many on there are engine builders so event though it is not apples to apples I am hoping someone here could answer this question. Basically what I need to know is if using 1/2" line with the fittings being .450" and about 60" of hose if this is restricting oil flow. To answer this we would need to know the flow rate of a high volume oil pump at 5000 rpm. Take a look at my post and see if you have any input
    Tim T.
    Post from OSO
    I am installing an oil cooler. The setup will include an oil thermostat and a large cooler from Eddie Marine. The size of the cooler (3x16 + 3x4 P/S) will require that I use the thermostat to ensure that the oil does not run too cool at cruise speed. The use of the thermostat requires that I have a total of four oil lines external to the engine. One to the thermostat, one out of the T-stat to the filter and two to the cooler. A local hydraulics shop can make the lines. The lines that they can make are for ½” NPT using a ½” ID line that will take 400 psi and 450 degrees. The only downside I see is that the fittings reduce the ID somewhat. The smallest ID of the fittings is 0.450”.
    The oil thermostat is from Perma Cool and is rated at 20 GPM. Is the ID of my 4 oil lines with the smallest size at the fitting of 0.450” using 4 lines with a hose ID of 0.5” large enough? What would be the flow rate of a high volume oil pump in a 502 using Mobil 15W-50W at 200 degrees at 5000RPM be? I anticipate with the large oil cooler that my oil thermostat, which opens at 190, should keep the oil around 220 or so max. Are my oil lines large enough?

    Tim T.
     
  2. jarheadk5

    jarheadk5 1/2 ton status

    Joined:
    Mar 6, 2000
    Posts:
    4,389
    Likes Received:
    0
    Location:
    PA
    The hyd. shop building the lines should be able to give you a ballpark flow figure for the lines they'd build for you. If not, I'd seriously consider looking for a different source.
    Is the motor a Mercury/Evinrude/whatever, or is it built by someone else? Give them a call and ask them about the oil pump flowrate with your given conditions.
    I'm not a hydro guru, but I don't think a 0.500" ID hose with 0.450" ID fittings is gonna flow 20GPM...

    September 11, 2001--"A date which will live in infamy"
     
  3. cpqtim

    cpqtim Registered Member

    Joined:
    Aug 25, 2000
    Posts:
    30
    Likes Received:
    0
    Location:
    Westport Ky.
    jarhead,
    The flow rate would not need to be 20 gpm, that is what the t-stat is capable of. Mercury Marine probably has no idea what a GM high volume oil pump flows, they just buy em. The engine is basicaly a high performance gm 502.
    Tim T.
     
  4. HarryH3

    HarryH3 1 ton status Author

    Joined:
    May 31, 2000
    Posts:
    10,384
    Likes Received:
    2
    Location:
    Georgetown, TX
    Mercury Marine probably knows exactly how much that pump flows. They test the crap out of their new engine designs before they sell them. When I lived in Florida a lifetime ago, a buddy of mine worked in one of their prototype shops. His job was to take boats out into the Atlantic and run the pi$$ out of 'em until something broke. Then they would tow the boat back to the shop and take the engine apart to determine what caused it to fail. Then they would repeat the process until he couldn't break it any more. [​IMG] Gotta be one of the neatest jobs I've ever heard of! [​IMG]

    <font color=black>HarryH3 - '75 K5</font color=black>
    <a target="_blank" href=http://www.angelfire.com/super/ThunderTruck>www.angelfire.com/super/ThunderTruck</a>
    It's a great day to be alive...
     
  5. ken

    ken 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    1,244
    Likes Received:
    0
    Location:
    Anaheim, CA
    Hey Tim, welcome to the board, nice to have a fellow Baja owner here. As to your flow problem, I think you'll be fine with that setup...I mean 20 GPM is do-able thru 1/2" line under high pressure. On my Baja, the oil filters mount to the exhaust manifold risers, for easy access (its got twin 454s), so there is a couple feet of line running up to them and then back down to the plate where the cooler lines attach (where the oil filter originally went). Good luck with your setup.


    ken
     

Share This Page