PDA

View Full Version : No flow?



blown69nova
05-08-2005, 01:12 PM
I just fired my new 383 sbc yesterday and I have a problem! The motor idles good but the temps just keep climbing over 200 until I shut it down. When I feel the upper hose it's cold, so obviously no water is passing through the t-stat or could there be an air pocket? How do you purge the air out? Any help would be appreciated.
Thanks, Steve

will69camaro
05-08-2005, 03:24 PM
Is it a LT1 based 383 or a standard old small block chevy? It was a pain in the butt to get all the air outa my LT1 since it only has one bleed screw (the one on the t-stat housing). I'd try pulling a heater hose and putting coolant directly into that then putting it back on when it's just about full and fill up the motor as much as you can so as to keep from getting air pockets.

William

blown69nova
05-08-2005, 06:17 PM
This is just a standard small block.

paul67
05-09-2005, 04:50 AM
don't forget to run the engine with the heater switched on.And also the water runs oposite to the standard small block .
i.e the top and bottom hoses are opp sides.
paul67

CAMAROBOY69
05-09-2005, 05:42 AM
When you filled the engine up with antifreeze and water did you fill it thru the radiator only? Usually the best way is to fill it thru the top of the block where the thermostat goes. Then you fill your finish filling the radiator.
Take the thermostat out and restart it to see what it does.

68protouring454
05-09-2005, 06:12 AM
if there is a thermostate on motor i would bet it is sticking, as the upper hose will stay cold until t-stat opens up and starts to let water circulate, i would pull t-stat housing off and check it, pull it out, and try it with no t-stat it will take awhile to warm up but should not overheat
also you can see thru radiator fill if the water is circulating as it will be dumping back in
jake

Kenova
05-09-2005, 05:02 PM
I have to agree with Jake, your thermostat is probably stuck. Pull it out, drop it into a pot of water on the stove, turn the burner on and monitor the water temp with a cooking thermometer. If it fails to open before the water boils, then it's bunned.
For all the time it takes, I always check a thermostat before I install it. Something else I like to do is drill a couple of 1/16 or 3/32 holes in the thermostat. This lets the air escape when you are filling the cooling system. It also allows a small amount of coolant to constantly flow past the thermostat when the engine is running. This will help prevent a steam pocket from forming under the thermostat and reduce the likelyhood of it opening and closing in an "all or nothing" manner.
Have you changed the water pump lately? I'm not sure what would happen if you ran a serpentine pump with a V belt pulley system, but I doubt it would work very well. (they rotate in opposite directions)
Ken

blown69nova
05-09-2005, 07:01 PM
Thanks for the replies. I decided to change the thermostat for the reasons stated above- another 160*. When I removed the upper hose/housing there was no water in the hose but there was up to the stat so I figure it must have been stuck. I refilled the radiator and ran it- still 210* but stays there.My fan is working, my brand new edelbrock pump is flowing and I even completely bypassed my heater core- still 210*. My last 383 ran about this warm too,do you guys think it could be the radiator? The rad is a stock replacement 3-core with maybe 8-10k miles. Help, I thought a 160* stat meant a car that runs at 160 or so.
Thanks, Steve

68protouring454
05-09-2005, 07:14 PM
is this 210 temp driving or idling?? if it is idling i would say you need an aluminum radiator and a better fan, look into a 2 row 1 inch or 1.25 inch row alum univeral radiator, then get a markviii electric fan from rockauto.com, this set-up will cool lmost anything for around 300-400 dollars
jake

blown69nova
05-09-2005, 07:23 PM
Yes, it is at idle. The mrk 8 fan will not fit my car, I already measured it up when we put one on my brothers vette.

68protouring454
05-09-2005, 07:25 PM
you need more cooling somehow then, i would go to a short water pump, or something, why won't the fan fit?? the novas are pretty much a camaro up front???
you need a fan pulling at least 2800 or so cfm, the mark vii is like 4000 or so, any pics?
jake

Steve68
05-11-2005, 02:39 AM
You need a bigger radiator and fan, something bigger or more efficient than a stock 3 core,

blown69nova
05-11-2005, 02:12 PM
I ordered a Griffin 2 row, 1.25 tube 26x19 rad. today. I'm also going to make a good shroud for my 16" fan. I will let you guys know how this turns out.
Thanks, Steve

KWIKND
05-11-2005, 02:56 PM
I thought a 160* stat meant a car that runs at 160 or so.

Steve,

The temperature of the thermostat is just the temperature that it opens not anything else. You could have a 120* thermostat and your car would still run 210*. The thermostat's purpose is to make the engine run hotter not cooler. The radiator's purpose is to make the engine cooler. You are on the right track, show us some pix when you are done! Good Luck
Dan

blown69nova
05-24-2005, 07:43 PM
UPDATE:
I installed the 26x19 griffin rad with 2 rows of 1.25" tubes, plus a shroud that covers the whole core with the 16" fan I was using before. All I can say is wow, what a difference that made! In the garage running for about 20 mins it never went over 185. I do have other problems now, but cooling is not one of them. Thanks for all the replies, Steve.