Rebuilt Engine Blows Water Out Of Radiator

[Mike Wertz]

I'm new here so let me know if I posed this in the wrong place.

I rebuilt a 289 out of a 68 mustang. I had the bottom end done at a local shop who cleaned the block and put in a new rotating assembly (Pistons, rods, crank, cam, and the timing chain) I then finished the build by putting edelbrock e-street heads and an edelbrock manifold. All the other engine parts are mostly stock. The first time I started the engine up to break it in, I had a serious overheating issue where hot water and steam would blow all of the hoses off everything and blow all the water out of the radiator. I was told by edelbrock that the overheating was because I needed to drill steam vent holes in the block for the heads. I did this and reassembled the engine using all new gaskets and cleaned all the surfaces as best as I could. I started the motor again yesterday and had more water come out of the radiator once the thermostat opened. I know it opened becuase I did not completely drain the block of water the first time and some kind mold/rust/dirt grew in the water passages I noticed when I took the motor apart the second time. When the water started coming into the radiator after the thermostat opens I shut down the engine and drained the gross water that the engine pumped into the radiator.

Is this overheating problem because some water passages could be partially blocked by the mold/rust/dirt goop? Or because of a head gasket problem? Or something else entirely? I hope its not a head gasket problem because that will require me to tear the engine appart for a third time. I plan to try and flush out the water passages to get the dirt out anyway, but should I do something else before trying to start up the motor again?

Thanks for any help

 

[horse sence]

sure sounds like passages are blocked also sounds like electrolysis is building up
.are you using anti freeze or strait water .its possible the block had sedament build
up and is breaking loose ,i always acid dip the block first it will clean out every thing
if it is still out of thr car i would pull a freeze plug from the block and look inside to
see if there is sedament in the block small block fords are known to have sand from
the foundry still in the blocks.aluminum will cause electrolysis make sure you use anti freeze never let one set with strait water

 

[rbohm]

when you pulled the heads the first time, did you check the deck surface for flatness before you reinstalled the heads? you may have warped the heads when the engine overheated. it is also possible that you installed the head gaskets wrong as well. als o start checking the little things like the radiator cap and its ability to actually hold pressure.

 

[horse sence]

the head gaskets are marked front on the gasket ad must be instaled with
front to the front or it will over heat.

 

[Mike Wertz]

When I took the engine apart the first time and sent it to the shop, they acid diped the block as well as making the deck flat (I forget what thats called). Both head gaskets are on correctly. I just tripple checked the tabs for you. I did not check the heads for warping because the engine only ran for at most 3 minutes before I shut it off. Could they have warped in that short amount of time? The radiator is brand new and the cap does hold pressure. I had the radiator cap off this last time because I wanted to make sure the thermostat was opening and the water was flowing inside the radiator. I have been using straight water because the engine will have to be pulled again anyway for when I get to the body and metal work.

Could this truly be just some clogged water passages building up pressure and then being released when the thermostat opens?

 

[horse sence]

is the thermastat in correctly? spring into the block ,strait water will ruin
a motor quickly it will rust almost immediatly and electrolysis will form
in the aluminum parts, i wouldnt think 3 minutes would hurt depends
on just how hot it got

 

[horse sence]

what head gaskets are you running? usualy front is printed on the gasket and
is under the head and not readable when the heads are on. one gasket may apear
to be upside down but that is correct as long as the word front is to the front

 

[bartl]

First things first. Completely fill the cooling system and do a pressure test. You may be able to rent a tester at a local auto parts store. It has an adapter that screws in place of the cap and a hand pump and gauge. Your system should be able to hold 16-18psi without losing any pressure over the course of 5 minutes or so. If it does, you have a leak somewhere. If the leak is external you will soon find water dripping.

Next, if you don't have a compressor, borrow or rent one. Using the screw-in adapter from a compression tester, screw it into each cylinder, one at a time (remove all the plugs) and plug it in to the compressor to pressurize the cylinder. Make sure the transmission is in park or neutral and your hands and other stuff is clear of the fan blades. If you hear air leaking from the carburetor that is air seeping past the intake valves. If you hear air leaking from the valve cover or oil breather that is air seeping past the piston rings. If you have bubbles forming in your radiator, that is air seeping from a crack in the block, head(s) or a defective head gasket.

If everything checks out okay, make sure you simply didn't overfill the radiator. A full top-tank radiator has the coolant level about an inch below the filler neck. If you have it topped off and the thermostat opens, all that heated (and expanded) water will force more out the top. With the cap on the system will simply build pressure and the boiling point will be reduced. Also check that the lower radiator hose is not being sucked shut by the suction of the water pump. Many of these came with a steel spring inserted in them for this purpose. Last, but not least, make sure you have the correct rotation water pump (which you probably do).

Good luck.

 

[Mike Wertz]

My head gaskets have a small tab that sticks out from under the heads on the side that says front. Thermostat is most definitely in correctly.

I will try and rent a pressure tester and a compression tester sometime this week and will let you know what I find out.

I may have over filled the radiator, but it seemed like quite a bit of water was overflowing. The lower radiator hose does not have a spring but was not sucking shut while the engine was on. The water pump is a stock replacement for a 68 289 so I am assuming it is the right one.

When I test the cylinders, do I have to position the crank any certain way for each cylinder? or just put the tester in and go?

Thanks for everyones responses!

 

[horseballz]

Mr. Wertz,
I have a few unasked questions and some thoughts/comments.
Questions:
>What does your temperature gauge read while the radiator is puking?
>Where is the temperature sender plumbed into the engine?
>What temperature rating and kind/brand is the thermostat?
>Do you have a shroud on the fan?
>What kind of fan and how close is it to the radiator?
Thoughts/Comments:
It is not at all unusual for a newly rebuilt engine to run a little, or even considerably hotter than might be expected, due to the added friction of rings seating and tight tolerances/clearances (a good thing in the long run) of bearings, valve guides, etc. finding their "happy medium"/breaking in. The important thing is to keep an eye on the actual temperature to not let it skyrocket to the moon. Many folks I know put an extra box fan, or such, in front of the radiator during cam/engine break-in to help, especially if there is no shroud. A little "boil-over" is not uncommon as long as the temp becomes steady at a normal to a bit above normal range and the puking stops. If the temp starts to go through the roof, shut it down. Let us know how you make out.
HTH,
Gene

 

[PoppyMod]

Hi,
Barring any incorrect installations of parts, it is not too unusual what you experienced. While it's true a newly assembled engine will be "tighter" therefore generate more heat, it's a possibility, this increase heat combined with trapped air and super heated internal surfaces is causing your puking. Before you tear everything down, remove your temp gauge sending unit and, at least, one other plug in the intake that has access to the water jackets. Fill your radiator slowly. As the level increases, in both the rad and the block, air will be expunged from those openings in the intake, otherwise it is trapped in the block and you don't get the level of fill you need. If after filling the rad and water does not begin to exit, one or both of those intake openings, proceed to add water through them until it does.
The thinking here, is to purge as much air from the block by displacing it with water/coolant. keep in mind, while your are breaking in a cam for example the engine is racing, first 1500, 2000 etc. unless you leave the T/S out, it takes several minutes before the T/S is fully opened and water/coolant is able to fully circulate. By this time there a number of super heated internal surfaces that will vaporize the coolant reaching it.
It is for these reasons, I'm a fan of coolant recovery systems that purge air and replace with coolant after a few engine cooling cycles. We all know coolant absorbs heat and carries it to the radiator, not air.
Good Luck!

 

[woodsnake]

Another easy trick to make sure that all the air gets out, is to just drill a small hole in the thermostat on 'top', in the flat part by where it goes in between the intake and housing....

 

[Mike Wertz]

Well to answer your questions, I don't have any of the gauges connected because the car is completely appart. My main goal is to break in the engine so that I know everything is working the way it should before I put it in the final product just to have it blow up or something.

I do not know what the gauge reads (Not connected)
The temp sending unit is in the intake manifold (closest to the front between the driver side head and the Distributor)
I actually cannot remember the type of thermostat I bought (I do know that it is either 160 or 180)
I know I will get many cringes right now, but I am not running a fan so that I wont chop my fingers off...I do have a household fan I put directly infront of the radiator.

As far as not letting the temp get out of control, the engine runs for about 2-3 mins and then the thermostat opens and immediately forces that water out of the top of the radiator. Seems to me like the water in the radiator being cool enough doesn't effect the overflow. Is this actually a boil-over?

Thanks poppymod for some ideas. I will try and do that next time. Are you saying that when the thermostat opens, the water will not force out the air that has been trapped inside the block?

Still have not had time to check pressures or compression yet. Is this the best way to find out if I warped my heads/put in a head gasket poorly?

Before I do anything else I would like to get the "gunk" out of the block before I ruin my radiator or anything else further. Any ideas on how to do that as well? (Maybe without buying the tools specifically made to do this, starting the car, or taking a freeze plug out?)

Thanks for everyones help

 

[PoppyMod]

Hi,
Relative to:
"Thanks poppymod for some ideas. I will try and do that next time. Are you saying that when the thermostat opens, the water will not force out the air that has been trapped inside the block?" No, I'm suggesting until the T'S opens, a lot of heat is being created. When the coolant does make it to those "hot spots" the coolant will be vaporize creating the pressure your seeing as it puke's it's guts. Again., this is barring any parts head gaskets, blocked coolant transfer ports, mal-functioning T/S etc. not correctly installed.
What can be happening is, when you pour water into the radiator, to completely fill all of the voids in the block air has to be purged. That T/S is closed until water in the block and heated is touching the T/S , heating the medium that opens the T/S. Until that happens there are many, what's called "hot spots" that will super heat as air is trapped, at or, nearby. This is why I suggested you remove a couple of those intake water jacket plugs, As water/coolant is being added, air withing the block is displaced and being forced out through those openings. When you see water at those openings, replace the plugs. Now, this is not to say "all" of the air is removed. This is what a coolant recovery tank will do after a couple of cycles. Ideally, you want to remove your rad cap and see the coolant level right at the mouth over flow tube to the recovery tank. This will indicate a fully purged system.
This is only my surmise at this point. Your issues, I've experience early on until I figured it out. Someone wisely mentioned drilling a small relief port in the edge of the T/'S as a air escape hatch. Very good idea.