my poor dead engine

Discussion in 'Big Block Cadillacs' started by richie49, Aug 27, 2018.

  1. richie49

    richie49 Active Member

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    Checked with the machine shop that did the work on my heads. He set the spring pressures at 125 closed and 325 open. Is this going to be too
    much for the caddy? The heads are already on the engine.:confused:

    Richard richie49
     
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  2. Roy Heisenberg

    Roy Heisenberg The 472 Crank is stronger due to overlap

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    Richard,

    Use some good break-in oil with high ZDDP, and you are going to be just fine. Many times the new springs will heat cycle and take a set after 4 hours of runtime. After the 4 hours, it is very common to lose 10% of the spring pressure, and then you will be in great shape. Use good oil like the Joe Gibbs, Brad Penn, Royal Purple with ZDDP, and do not let it idle at all during the break-in period. After the 20 minute break in, drive it easy for the next 500 miles. Then put in fresh Royal Purple synthetic, and unleash HeLL!

    Regards,
    Bro. Roy
     
  3. Cad Man

    Cad Man Active Member

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    What cam is it..

    Mt15 cams are good with 90-95 seat. 260 - 270 open.. that is if your spinning it 5500 .. With big valves

    If you have smog heads you won't be doing that. Maybe 4800
     
    Last edited: Jan 11, 2019
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  4. Roy Heisenberg

    Roy Heisenberg The 472 Crank is stronger due to overlap

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    If you have 250 open, you can spin it to 5,000 RPM all day long. Most people run excessive spring pressure. You are gonna be just fine. A bit more pressure just means you can spin it harder, miss a shift, and still be OK.

    Thanks,
    Roy
     
  5. richie49

    richie49 Active Member

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    hello everyone
    Putting this engine back together is taking forever it seems..Have too keep on waiting on parts.The set of pushrods turned out to be too short so Im getting the next size up and IM going to have to shim the rockers to get correct preload.Im waiting on getting the rockers set up before I see what i have to do for the valve covers.
    I have a question and would like some opinions. Would having the hose on the back of the passenger head help cooling having it hooked up to the cooling system? (its not being hooked up to a heater just the hoses going to the radiator)Would it help to keep air from in the pockets in the engine?
    Richard richie49
     
  6. Cadillac Kid 1

    Cadillac Kid 1 Well-Known Member

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    Richard,
    If you run a hose from the heater supply fitting at the rear of the passenger side cylinder head directly to the standard location on the radiator you are hooking it up to the "cool" side of the radiator and rather than help it will hinder cooling since that water doesn't get cooled but is recirculated back to the motor. The standard trick (I believe) is to plug the bypass under the thermostat, drill an 1/8 inch hole in the plug to vent the circuit and use a high flow (Chevrolet type) thermostat. Plug or cap the (heater) cylinder head out.
    Greg Surfas
     
  7. richie49

    richie49 Active Member

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    Greg
    My radiator is in the back of the car(corvair) I was going to hook it up on the suction side,it'll have a ways to go to the radiator and back..:) Mainly wondering about air pockets in the block.
    Richard richie49
     
  8. mario

    mario Well-Known Member

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    Hi greg:
    I ran the passanger side head fitting to the heater, then the 'out' side of the heater to the return hose that runs back to the water pump. Using the caddy Stat with this. Plenty of heat from the heater without running hot in the engine.
    Ciao,
    Mario
     
  9. sickboi55

    sickboi55 Member

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    Shimming the rockers should be for the contact pattern on the valve, not pre load. On non adjustable rockers preload is a function of pushed length.
     
  10. 48Austin

    48Austin Safty First! Then pull the trigger!

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    Use a vacuum bleeder.
     
  11. 48Austin

    48Austin Safty First! Then pull the trigger!

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  12. Darius

    Darius Well-Known Member

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  13. richie49

    richie49 Active Member

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    hello everyone
    I'm having a lot of problems measuring preload.I have tryed a dail indicator but I cant find a spot on the rockers to get a constistant reading. I have tryed the way of making a mark on the pushrod and tightening the rockers and also tightening the rockers and marking them then loosing the rockers and marking.using the finist tip point marker the marks are hard to measure. .020 to .050 are hard to see. Using marker system I am getting 21 to 24 I think. Is anyone running the 15 cam with the non adjustable shaft rockers and what lengh pushrods are you using?

    Richard richie49
     
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  14. Roy Heisenberg

    Roy Heisenberg The 472 Crank is stronger due to overlap

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    I say just Goto a solid roller cam, and get out the DyeKem Blue and feeler gauges. Hydro cams are silly, and Solid Riller is the key to power. Just do it, and make CadMan proud.
     
  15. Red98422

    Red98422 Active Member

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  16. Roy Heisenberg

    Roy Heisenberg The 472 Crank is stronger due to overlap

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  17. Red98422

    Red98422 Active Member

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    Roy: are you asking why set up the preload for a HFT?
     
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  18. richie49

    richie49 Active Member

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    Hi
    just to clear up any misgivings,I wasn't asking why set preload but how. The way outlined by marking pushrods wasn't working and with a dial indicater
    I wasn't getting the same results twice on the same rocker. I got the preload set by using a wire gauge between the pushrod cup and the wire retainer on the lifter,not easy but it works.
    Roy
    A roller cam would be excellent except IT'S way out of my budget. This is a mild rebuild with no future plans to upgrade my engine.I have been working on this car for way too long and its time to
    drive and enjoy it.If I can get the dang engine finished.:):D:whistle:.

    Richard richie49
     
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  19. Red98422

    Red98422 Active Member

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    Glad to hear that you found a resolution to your problems! Get her running and enjoy the heck out of it...spring is right around the corner!
     
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  20. 2JvLo

    2JvLo Member

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    Can't wait to see this one finished. Richie could you make a video once you get it running?
     
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