BadAzz94Z

Hey guys, I made a thread for this build when I first started.

Basically its a 94 Z28 with a 468 and T400.

I've tried a 160, 180, and now a 195 degree thermostat. The car idles to 200 and then drops to about 180. So the 195 thermostat is working fine.
But when I drive the car around the block it gets up to about 230, sometimes even 240.

The radiator is full... We're stumped.

If anyone has some ideas, I have open ears. Thanks guys.

BassProCamaro97

iTrader: (10)

Are you purging the radiator at all?

What type of radiator are you using? How about fans?

I'm chasing the same problem right now but I think mine is due to air pockets.

Good luck,

~Jim~

BadAzz94Z

It's just a Jegs universal aluminum.

It's 28x16.5". It's in there snug. No room for any bigger than that.

The fan is 14" if I remember correctly. I think it pulls somewhere around 1700 cfm.

We purged the motor as much as we could without using the garden hose. We dont want there to be only water. We want to use antifreeze until we take it to the track.

And I'm pretty sure we have the same problem you do, we changed the thermostat...and there was hardly any water in the intake. We're probably gonna end up havin to purge it with the hose.

Thanks for your comments, man.

BassProCamaro97

iTrader: (10)

Are you runing any sort of vent tube from the back of the intake to the thermostat housing?

Some things I'm looking at possibly fixing my problem are a fillable thermostat housing. (has a radiator cap on it and also has a threaded hole which will allow you to run a line to one of the back plugs in the intake.)

If you have access to one get a vacuum system to pull the air bubbles out of the block. It didn't work for me but you never know. Also try jacking the front of the car ay up and burp the radiator like that. I'm talking 3-4 feet in the air.

Good luck,

~Jim~

jimmyblue

iTrader: (11)

Drill a little hole inthe 'stat so any bubbles can be
pushed through. I used to do that on all my GM iron
motors, on account of having troubles in that vein
once. The LS1 has a built-in bubble check valve in
the thermostat.

I dunno about big blocks, but my 400 small block
turned out to have a non-400 head gasket on one
side (alleged virgin, no less) and no steam holes.
That led to some "issues".

On the other hand I've had cars where you got
some inserts to plug certain holes to force proper
coolant distribution balance.

Turbojet307

My brother had a newer cobra mustang that had alot of problems with air in the cooling system when it was new.

With the front of the car elevated, and the radiator cap off running until it reached operating temp would get the air to the high point and out the fill port

BadAzz94Z

Thanks for the advice fellas. Sadly, we are taking the motor and tranny out on Monday. Gotta have the transmission looked at. We are buying a bleeder and an insert to get all the air out when the motor and trans go back in. Hopefully this is all figured out soon.

1320

iTrader: (6)

You probably need more air for the power its producing to thermally meet in the middle.
I would expect it to over heat with only a 14 inch fan.

I call livernois and ask about their fans. I run them, I dont know where they get them, but its a dual set up at a great price. Probably double what your pulling now.
Other then that, make sure the timing isnt too retarded, seal up the radiator edges well so all the air entering has to go thru the radiator.

Straight distilled water cools better then coolant, also.....cylinder head temps are lower by about 15 degrees.It all adds up.

Make sure there is an air escape at the rear of the hood to let under hood air out also. Sometimes requires cutting, sometimes just removing a rear hood seal is enough.

F-Body Lover

change the fan to dual set up with something over 2850cfm

Nosbaby

im having the same problem with mine. mine is just a race car, but when I get to the end of the 1/4 mile, my temps are up to 220 to 230 sometimes. I have a electric water pump and I just dont think its circulating enough water, I have the same aftermarket radiator as mentioned above. single 16" fan pulling 2200 cfm.
I jacked the front of the car up as high as I could get it, but still have same problem.

any other ideas?

BadAzz94Z

We figured it out. There was a big air pocket. It has been fixed.

Transmission is still coming out tomorrow. The car should be running this time next week. Thanks for your interest fellas

Oldsmobility85

iTrader: (1)

Also if you like to use the 3/8 npt port on the side of the head to locate your temp sensor theres alot of heat that soaks in right there and the intake near the thermostat is the best place to place it. Went through this with my fan thermostatic switch. The darn fans would stay on for nearly a half hour before they quit.