Ok Heres a quick overdraft of my car... Its a 1983 Z28 The Original Engine in it was a 305 V-Belt Drive with A Holley Street Dominator Intake And Edlebrock 600CFM Carb... I blew that engine and swapped a 91 RS 305 With Serpentine Belt Drive Into My Car.. I swapped the TBI with my Intake and carb and threw on the electric fan with it. I have no thermostat in the car and the fan is hooked to a switch for constant cooling. Now my car will not stay at a certain temp... the longer it runs the hotter it will get... Driving it for over and hour wether in the streets or on a highway will push the temp over 200 and will continue to push up to 260 if i let it run long enough.. The radiator is in newer condition, and seems to run water through the system like it should.. Why is my car running so hot?

 

do you have an air dam? thats the first ques and is the fan pulling air thru the rad? or do you have it setup to push. do yu have a T stat or are you using the one that came with the motor? if so it may be stuck shut. when you say "newer" on the rad what do ya mean by this? make sure its not blocked by road stuff that can get lodged in the fins. this should get ya started.

 

As for ther air dam.. no, it got taken off and lost during the engine swap... the fans set to pull air through the radiator. It has no thermostat i figured i live in florida so theres really no use for a thermostat.. and as for the newer radiator when i bought the car a year and a half ago the guy i bought it from claimed the radiator was new.. and during inspection of it during the engine swap it looked very clean and new so i dont thing my radiator is an issue with it.

 

the air dam is VERY important on our cars, its the source that makes the air go up to the rad. those front 2 holkes in the nose arent enough, it NEEDS the air dam.
no stat, thats another reason your running hot. without a stat the water constantly runs thru the motor and stright thru the rad with no cooling time. if you had a stat the cooant would get cooled in the rad and then when the water hits the opening temp of the stat it flows coolant which is what cools your motor then the hot water from the motor gets its time in the rad and cools down.
i sugguest at the minimal a 170 stat for a stock EFI car. the "sweetspot" for the ECM to go into closed loop is 167 IIRC. the ECM isnt fully happy til after that temp.

 

You have two issues that must be taken care of.
1) Install a AIRDAM which is important cooling part.
2) Install a 180 deg thermostat.

Also I would power flush the cooling system and install fresh ant-freeze.

I also live in Florida and my only cooling problem is running 220 deg with my A/C in traffic. So go what was stock on the car and stop trying to be a cooling engineer.

 

well the car isnt EFI managed.. its carbureted.. so its a manual fuel pump. and as an added note the car has never had a thermostat even on the old block.. but maybe an indicated reason of why i slung a rod... but that still makes no sence either.. i drove the car for 6 months before it blew and never had a running hot issue

 

Put the air dam on. Put a T-stat in or a water resticter. Doesnt matter if your car isnt EFI managed. Whats happening is the coolent isnt staying on your radiator long enough for it to be cooled. The water pump is moving it threw the system to fast, and the t stat slows it down...

 

Right, thanks for all the help hopefully this will solve one of the many issues of my car..