383 stroker overheating

I have been reading on the forum on heat problems with the 383 strokers. I have went back and checked everything to find the heat guage is running around 220. When I shut the motor off, the heat temp goes way up past 230. I have adjusted the carb several times. Checked to make sure the timing is around 12-14 degrees. I checked the radiator to see that there is a small flow from the radiator core. Should the antifreeze be running fast rather than a small flow? I have a set of the S/R world heads with the 2.02 valves/160. Is there a chance that the heads VS the 1985 block have different water port holes? I was thinking that the motor is still tight,no miles on it. Maybe just driving it may just all it needs to break in. Any suggestiions would be appreaciated. thanks  

put a colder thermostat in it. also water weter will drop your temps a little. your not to far off try those 2 things and it will probably drop.  

what size radiator do you have? 220 is the limit if you have high compression, it needs to be 195 or lower. you should have at least a 3 row copper/brass or 2 row aluminum. are you using electric fans or direct fan?  

Thanks for the info. I have been off the net for a while since I only had a couple weeks of leave time in the states. I put in a 195 temp thermostat. My new radiator is a three row aluminum radiator. I replaced the water pump also. I am just running the stock fans and no electric fans. I was thinking that at one time someone told me not to run straight antifreeze. When the car is running down the road, it is up around 210. At idle it will go up to around 220 or a little over. The motor is still tight after being new.  Thanks  

You say stock fan, I assume this means 5 or 6 blade with a temp controlled fan clutch. If so are you sure the clutch is good, is the guage is accurate, on the coolant you should never use more than 50% antifreeze because glycol dosent transfer the heat as good as water nor does it protect from freezing at lower temps.  

Thanks for the info. I remember years ago that you never run full strength coolant. I just have been away from the motor head things to long. I sure appreaciate your imput as this put's me back into where I need to be. I will go back and double check the fan clutch and make sure it is ok. Summer months are getting near and I want to make sure it is running cool. Thanks again for all your help.  

Hey I  know exactly what your problem is. Your water pump.  Your by pass hole is covered or plugged at the pump mounting flang.  I found mine filled with sealant causing my internal bypass to crap out.  I cleared the hole and installed a new pump and my temps came down to 180 with a strong flow thru the radiator.  

Ok, back to square one again. When the temp is cool out, it seems to not go much more than 220. Now the temp outside is in the 50's. With that in mind, the temp is starting to climb to around 225-230. I did install a new water pump. It is a new, stock pump. In the one reply it mentioned about checking the by pass hole. I am trying to remember, I don't remember seeing any by pass hole in the new pump. Where it mounts to the block is just two large holes. No extra hole for a by pass.  Now this is a 1975 chevy block.  I have a new three core aluminum radiator in the car with a new clutch fan. Another guy mentioned that I may need to get a water pump other than stock that will push more coolant. Will this help? I still have the stock five fin blades on it. Would it be best to go with a 4 core radiator also?  What about adding an electric fan? I still have the air conditioner unit in front of the radiator. Would it be best to take that out? I replaced the heater core in it a few years ago, so that should be ok.  Just one other thing, I am just shooting in the dark, on the heater core hoses, which one goes to where. Im double checking to make sure I have that correct. One goes to the water pump and the other to the block. If those were hooked up wrong, would that cause it to over heat? I can hit the heater fan on and it will drop it down about 10 degrees. Any ideas would be appreaciated. If there is a by pass hole in the water pump, give me an idea of which side. I do not remember seeing one. I have a full gasket on that. Thanks..........  

HI I HAVE 68 CAMARO WITH 383 WORLD HEADS AND I HAD THE SAME PROBLEM 220 TEMP ALMOST ALL THE TIME. I INSTALLED 2 ROW ALUM BECOOL RADIATOR WITH ELEC FANS AND TEMP WAS STILL HIGH 200. PUT ALUM HIGH FLOW WATER PUMP STILL COULDNT GET TEMP DOWN. TRIED 195, 180, 165 THERMOSTAT. FINNALY I WAS TOLD THE 383 RUNS AT GOOD TEMP WITH THERMOSTAT REMOVED SO I RAN IT ALL LAST SUMMER WITHOUT THERMOSTAT. IT WAS AMAZING IT RAN AT 180 TEMP ALL THE TIME EVEN WHEN AT LONG RED LIGHT IN TRAFFIC ON 95 DEGREE DAY MY CAMARO IS BLACK AND IN THE SUN. IT SEEMS TO RUN PURFECT WITHOUT STAT.   I HOPE THIS HELPS WITH YOUR PROBLEM!! I HAD THE SAME PROBLEM BUT NOT NO MORE THANK GOD!!  

I WOULD BE CHECKING THE CLUTCH  COUPLING FOR YOUR FAN . MAKE SURE ITS IN PROPER WORKING ORDER AND MAYBE EVEN CHASE UP A  SIX BLADE FAN FOR IT!  
there is no substitute for cubic inches

220 to 230 is normal operating temps on later model motors... nothing to worry about...  as long as there is a proper mixture of coolant and water... and the radiator cap holds the proper amount of pressure...   13 to 16 psi...

the bypass hole on the pump is on the passenger side of the motor...   right side looking forward...  that is why there is a spare hole below the bolt hole in the water pump gasket...  

removing the thermostat works in some cases.. but controlling the motors temps stops it from thermal cycling...    this is the death of some motors and cylinder heads...  the heads expand and contract with temp changes...  without a stat... the changes can be extreme. on long high speed drives the coolant moves through the radiator fast enough that the fans don't have a chance to pull the heat out..

the water pumps can also pump enough flow to build up tremendous pressures in the top hose and top tank... this on brass tank radiators will swell the top tank... and can blow them off the core header..

so it all depends on how much cooling ability you have... and if you really want it to run below 200F..

as for the heat soak after you turn off the motor... that is totally normal...   the engine is hot... when the cooling system stops... normally the gauge power is cut off when the key if off..   the temps will increase on every motor when it is shut off...

does it belch coolant out when it is shut off????   does it blow coolant out when it is running other than the normal expansion into the overflow tank?????  

The motor seems to be running ok. There is no belching or anything. I was reading some of the other post a couple months ago as it was talking about keeping it around 200 degrees. I did see in summit that they have a water pump that pushes more volume than a stock water pump. I did not know if it was going to be a waste of my time. If the temp is normal around 220 to 230, I will just keep an eye on the temp guage when the weather get's hotter. I did notice that once it got up around 225-230 the oil preasure dropped around 10 pounds. I understand once the motor warms up, this is normal. It is just that this is a newly re-built motor, for the third time and wanted to take every precauction and not destroy something due to lack of preventive maintance. Now that you mentioned about the by-pass hole , yes i remember it being on the passenger side. I made sure the gasket was put on correctly. I sure appreaciate your imput and help. Thanks  

Have you tried increasing main jet size? If it is running to lean you'll never get it to run cool. At least it's easy to check. Go up 2 or 3 jet sizes in the front and back if the carb you have has a rear metering plate. One other thing you might check is make sure the exhaust is not restricted (clogged converter/collapsed pipe)  

Thanks, What I have on the motor is an Edelbrock 650 carb. It is new. I don't know much about the carb as I always had a Holley before. The only adjustments on the carb is the two adjustments on the front. What do I need to do to change out the carb to different jets? Is this going to be a dismantal and change internal parts? I was asking the kid what took place as he mentioned that when he kicked it down, it blew out a little smoke as it seemed to e loading up. The temp was running at 230 and when he turned on the heater it cooled it down to 220. It just seemed like it was at a loss of power at that temp. Im guessing that changing out the jets may help this. My concern is now, the way the motor was running at 40 -60 pounds oil preasure it got down to about 20 pounds. With the thing heating up, will this affect the oil preasure?  What about the three core radiator, it is new, should I also go up to a four coor or is a waste of money?  thanks, i appreaciate all the help on this.  

I was just thinking, since I have a Edelbrock 600 on this 383, is it possible that the carb is to small for this set up and cause the over-heating problem of burning to lean?  If I went to a 750 edelbrock carb, would this take care of the problem of burning to lean and causing it to over-heat. One of the motor heads here was just telling me that I need a bigger carb for the set up of the 383 stroker. Would the 750 carb be to much for that motor?   thanks