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cooling problem

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Gus and mrs. skeeter
There are Air Boats in Utah
285080_1899249396492_1099359771_31560569_7354932_n
tellico
newcoating
Sunset on the lake
F

FLrooter

Active member
i can't get my water pump on my sbc to pump. the pump is new, the hoses are new and the rad. has been checked at my local shop. anyone else have this problem and if so how did you fix it?
 
You need a belt between the crank and waterpump. sorry ! just kidding. Airlock is the only thing on SBC that I can think of at the moment! Don't remember being able to screw up head gaskets, intake gaskets or anything else at the moment but knowledge can make you complacent. If you are running a thermostat make sure there is water below it before you strart it up. Water pump sucks and pressure at intake. On tough one sometimes losening a thermostat housing cover bolt is enough to bleed off the air>
 
i thought about putting some water iunder the thermostat housing and also filling the hose up that connect to the water pump. sound like it might work?
 
will usually bleed if you are just running a restrictor, with a thermostat if there is air underneath, it will not open and will boil. Even a bigger problem with rad mounted down low but you need a bleed from the underside of the thermostat or like I said loosen a nut and make sure there is coolant is contacting the bulb of the thermostat (witch is pointed down). Pouring coolant in from the top with a loose housing bolt will not always do it as you will see coolant cunning out. I guess fail safe would be filling cooling system with thermostat out, installing housing and topping up. It would just be nice to have a valve that, don't know what kind of intake but I usually remove heater hose and have water there, so little t valve on heater hose out will usually work. But sometimes they are just a pain. If that doesn't work I have run into problems with Impeller depths, chevs don't have seperator plates but fords can, however will usually still pump, not very common! I don't remember if chev has a reverse rotation, actually I think they do but I think it's serpentine belt. Weird stuff can happen on the assy line. Impeller could have shown up from wrong line! good luck!
 
Have seen bleeder valves on the intake manifold to get rid of air pockets and also saw a few on top of the thermostat housing. Don't know if those ideas would help your problem.
 
Just a note, if you are running a thermostat, Top of the thermostat housing does not help any. Some of the thermostats you can get have ball bleeders in them that work OK. Better than nothing, just take a little time. They do just have to work once after drain down after all dont they?
 
if you drill a very small hole in the plate of theremastat it will allow the air to bleed whenever you are filling and running to ensure you have fluid in upper end and usually will not effect operation of thermastat ;copperhead
 
Good point, I was actually going to suggest that. crossed my mind after I posted. 1/8" should do the trick!
 
If it works for your installation, Moroso (sp?) has a pretty cool piece that will solve this for you if your radiator is below the engine. It's a block that bolts to the intake in place of the upper hose fitting, and it's where the radiator cap screws on. It's the highest point in the system, so when you fill the cooling system there are no air pockets.

Jegs or Summit ...

K.
 
MUST RUN BURP TANK. And you must plumb it correctly so all the air that travels thru your cooling system ends up left in the tank. This burp tank will also give you head pressure at the inlet side of the water pump. I have fixed ton's of boats that ran hot. Once you get this right it will be trouble free.
 
I fixed that problem place nipple in top of Thermostat housing and run hose up to your fill tank.
Just like waterthunder said
 
so i need to put a nipple on the thermostat housing and run a hose up to the overflow tank? sounds simple enough......thanks everyone
 
The best way to end any air pocket problem is to run a fill tank and locate it above your engine. Run the hose from the bottom of that tank to either the thermostat housing or the inlet of the water pump. On all my LS-1’s I run a 3/16 hose of the back of the heads into the side of the tank. This way a little coolant is circulating thru the burp tank and when it get dumped into the burp tank the air is separated from the water then only the water gets picked up from the bottom of the tank. Classic sells a burp tank that works great and also runs on this principal. But it uses two 5/8 hoses and one goes to the top of the radiator it works great but I just prefer not to divert that much coolant.
 
Moroso makes a nice " T " fitting that you can put inline between the thermostat housing and the radiator (at the highest point). It has the nipple to run hose to the burp tank. That and a weep hole in the thermostat works great.
 
Not trying to sound like a smarta** and I'm not even sure this can happen on a SBC but might be worth a look to make sure the thermostat is not upside-down. Might be Chevy has a neck that wont allow this but on that issue I bet lots of folks here can say if its possible or not. Especially with an aftermarket neck.

Best luck

Scotty
 
One VERY important thing that I have learned from dragsters, altered’s and airboats. Is you only want the radiator cap at the highest point in your cooling system and I have come across at least 5 airboats that overheated because they had two radiator caps. I got rid of the lowest one and the boat quit overheating. So I strongly recommend to locate your radiator cap at the highest point. I have seen boats with them lower but I have seen the majority of them have cooling problems or a hard time burping the system. I feel the best place to add water and locate radiator cap is at the highest point in your cooling system. I personally have never owned a boat that runs over 160 degrees most run 150 and my ride boat motors are usually around 11to1 compression. Recently I have had three of my motors over heat or run too hot and I had the customer bring me their entire boat in all three boats the overheating was caused by two radiator caps or their burp tank location or plumbing. After a few mods all three boats ran around 155deg.
 
Speaking of thermostats- my 500 has a 190 degree in it as is stock and it runs right at 190-never over. 190 just seems awful close to disaster to me. Should I consider a cooler one or is this fine?
 
I run a 160 in my Cad. I've tried no thermostat and taking the guts out of one but when I idled for long periods of time it would creep up to about 180 which was making me nervous, especially after blowing 3 head gaskets on a new build up due to uneven head surfaces. I wouldn't run a 190 but everyone has an opinion.
 
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