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Hot Rods Starting freshly built engine without water in block ?

Discussion in 'The Hokey Ass Message Board' started by blazedogs, Jan 21, 2018.

  1. blazedogs
    Joined: Sep 22, 2014
    Posts: 407


    Before starting a new engine there are things to do prior to starting it ,prime it to circulate the oil etc. A new engine will absolutely have no water or antifreeze in it.The water jackets will be dry ! If a thermostat is installed it will not completely be open till the block reaches operating temp in most cases 180 degrees.Should the engine be first started with the radiator installed with water, by running the engine( without any thermostat) ?? Gene
    chryslerfan55 likes this.
  2. I was taught to add the coolant to the radiator and let it gurgle into the engine with no thermostat. If you raise the front of the vehicle it will help with burping the system. Reinstall the thermostat with an 1/8 hole in the flap. With this system there will be plenty of coolant in the system for the start up.

    I always use water instead of antifreeze initially . For some reason I always have some sort of coolant leak and water is a lot easier to clean up than antifreeze. After the cam break in I change the oil, filter, and change the coolant from water to 50-50 antifreeze.

    Your mileage may vary.
    '51 Norm, bchctybob and olscrounger like this.
  3. Torana68
    Joined: Jan 28, 2008
    Posts: 1,131

    from Australia

    Yes to water, thermostat yes also, you want it up to operating temp sooner rather than later, drill a small hole in the thermostat to help get air out if thats a issue.
    bchctybob and olscrounger like this.
  4. squirrel
    Joined: Sep 23, 2004
    Posts: 44,641


    If there's a really good reason to start an engine without coolant, I'll do it..but usually I fill it up. Water is probably a good idea if it might have leaks, but not a good idea if it will freeze up and crack because you live in Minnesota.
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  5. manyolcars
    Joined: Mar 30, 2001
    Posts: 8,163


    I start up without water to make sure it will run, then add water to check for leaks, then add antifreeze
    stillrunners and wbrw32 like this.
  6. Ouch.
    If you dont have water in the water jackets, you will have some severe hotspots in a matter of seconds, with no way to spread out the heat.
    Never do that to a fresh engine that hasn't seated-in the parts or broken-in yet.
    Iron-warping hotspots are damaging enough in a loose worn engine.
    p.s. the thermostat will not get the temperature info without water flowing by to tell it the message.
    YES, there IS some water flowing with the therm closed.

    Last edited: Jan 21, 2018
    egads, nochop and Truckdoctor Andy like this.
  7. manyolcars
    Joined: Mar 30, 2001
    Posts: 8,163


    When I say I start it and let it run. I am talking about 60 seconds! Its not going to hurt anything
  8. BJR
    Joined: Mar 11, 2005
    Posts: 6,095


    Just can't cut us frozen guy's a break can you!:p
    Beau and stillrunners like this.
  9. squirrel
    Joined: Sep 23, 2004
    Posts: 44,641


    going to be 24 in the morning here....
  10. F.O.G
    Joined: Oct 31, 2006
    Posts: 259

    from Pacific,Mo

    I always fill radiator with water and no thermostat until water comes up to level of thermostat THEN
    install thermostat so it will open, no air lock. I never put anti freeze in until inital break in is completed,
    had bad leak into oil once and wiped out new engine. My error.
  11. Truck64
    Joined: Oct 18, 2015
    Posts: 3,880

    from Ioway

    A surprising number of people don't run either antifreeze or a thermostat, thinking they don't need that stuff where they live. The last several weeks have been kinda rough on 'em.
  12. Black Panther
    Joined: Jan 6, 2010
    Posts: 1,520

    Black Panther
    from SoCal

    You have to let it run for more than 60 seconds if you're breaking in a cam. If you are...itll have to run at least 20 minutes...drill a hole in the thermostat...or be ready to add water when the thermostat opens and the water level drops..
    Fordors, Terrible80 and bchctybob like this.
  13. buffaloracer
    Joined: Aug 22, 2004
    Posts: 786

    from kansas

    When I start a new engine I want water in the whole engine. I don't plan to turn it off until the camshaft is broke in. I often but not always leave the thermostat out.
  14. doug warren
    Joined: Apr 3, 2017
    Posts: 37

    doug warren

  15. doug warren
    Joined: Apr 3, 2017
    Posts: 37

    doug warren

    On a new engine I may crank it over to see if she pops and dist is in right and thats about it. hard on the water pump also running it dry, from how I was taught. And get a quick glance at the oil pressure. That would be about it.
    blowby likes this.
  16. rusty valley
    Joined: Oct 25, 2014
    Posts: 1,006

    rusty valley

    years ago when we had real junk yards, most would start an engine laying on the floor to show you "its a goodun" no harm done
    squirrel and '51 Norm like this.
  17. bchctybob
    Joined: Sep 18, 2011
    Posts: 1,963


    I usually have everything ready to run for the cam break- in. Thermostat included. I try to fill it with plain water and let it sit for a while, look for leaks, then check the oil to be sure no water is leaking internally.
    I have started them dry (with no fan belts) to be sure it will start and I haven't missed on the timing, but only for a few seconds.

    Sent from my iPhone using H.A.M.B.
    Joined: Jul 20, 2006
    Posts: 2,162


    A new engine at any engine for that matter should never be run without coolant . If you have an air lock take the heater hose off the intake manifold and fill it until coolant comes out. Put the hose on and finish filling he system.
  19. squirrel
    Joined: Sep 23, 2004
    Posts: 44,641


    What about a race engine that doesn't have any water jackets?
    Bugsy48 likes this.
  20. Just sprat the outside with a hose while it’s running....

    Sent from my iPhone using The H.A.M.B. mobile app
  21. Yeah, but aren't they designed for that? No more than a couple of minutes or so before the race is over.
  22. squirrel
    Joined: Sep 23, 2004
    Posts: 44,641


    yup. The point is, you can safely start an engine without coolant. How long you can safely run it...that depends.
    belair likes this.
  23. I am not as scientific as everyone else. I fill the radiator with water on a fresh engine and light it off. I leave the cap off and have a hose handy, I run it until the cam breaks in then I slow it down let it cool a bit an shut it off. It works for me.

    If I had a fresh engine and needed to break the cam in ( as in flat tappet cam) I would make sure tht there was water in it, I have had to shut them down during break in before but prefer the break the came in all in one jump.
    olscrounger likes this.
  24. If the title was "How do I add coolant & remove air" the replies would be more to the point?
  25. Blues4U
    Joined: Oct 1, 2015
    Posts: 4,336

    from So Cal

    The difference being the OP asked about a new, or freshly built engine, and you're talking about a used engine in a wrecking yard. A freshly built engine may have a new cam/lifters that need to be broken in.
    olscrounger and porknbeaner like this.
  26. nochop
    Joined: Nov 13, 2005
    Posts: 1,416

    from norcal

    Make sense to me
  27. studebaker eric
    Joined: May 9, 2008
    Posts: 1,507

    studebaker eric
    from Diablo Ca.

    After all the effort and expense of a rebuild, why leave anythimg to chance
  28. Hey Gene don't make me come up there. Hey Jim (@squirrel ) pick me up lets go break Gene's motor in for him. It'll be fun. :D :D :D
  29. I want that new engine to be able to run for a solid 1/2 hour as a minimum. Pre-oil the crap out of it, get the distributor in the ball park (at least dropped in right...), 50-50 coolant and a thermostat. Have a couple of guys around that can think fast... then I light it off. The last was my 355 Chevy and it went off without a single hitch.
  30. LOL when we lit my 355 off the first time it was with open headers and split a combustion chamber ( never had that happen before). We jammed a hose down the radiator and let it blow water out the header until the cam was broke in, pulled the heads while it was still hot and started drying it out. That was 21 years ago this year.

    Shit happens and the best thing is to just be ready for it. Sometimes you pull it off without a hitch and others you just have to improvise.

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