I need help with my 468cu in camaro. In traffic or on the freeway im running about 230 deg. When I stop I boil over. weiand 671, be cool radiator with dual 13" fans , restrictor plate medium size(instead of thermostat)distributer locked out timing 28deg., Holley 750's (2) (not running lean) 3000 stall converter, tried water weter, ran ok in 70 deg days, boil over in 90 deg. days. edelbrock high flow pump, 3" exhaust, 2 1/4 headers. Please help I at a loss.
thanks
Rick  

with the restrictor instead of a thermostat.. the coolant just circulates through the radiator.. back through the block and heads then through the radiator again...

it is going so fast it does not stop in the radiator long enough for the cooling fans to take the heat out of it...

on 70 degree days there is enough differntial in temps to cool the engine... on 90 + days .. there is not...  

put in either a 180 or a 195 F stat...     try the 180 first....  then watch the cooling system....    OH!!!!! you need to have a bypass system between the crossover and the water pump inlet..      or the stat will not get enough circulation past it...

you can also drill a 1/8 ot 3/16" hole in the stat to allow a bit of circulation ..   probably a good idea...

how are the fans controlled.????  just run all the time...  or with a temp sensor in the intake coolant passage ... not in the head between the exhaust ports...  

some brands of fan controllers have a probe that goes into the fins of the radiator... others have a probe in the upper hose so when the stat opens the hot coolant passing over it turns the fan on...    

but the most important thing is the ability to keep the coolant circulating in the block until it comes up to temp... then swap it into the radiator... the cool water in the radiator cooling the motor slightly while the coolant that is stopped in the radiator is cooled by the fans or ram air through the grill....  

Thanks for the advise, I left a few things out. I started out with a 180 deg. stat, thyen tried a 160 deg, both had a small hole drilled in the top. I also have a by-pass that was installed from the pump to the stat housing. I thought that the pulley size on the pump might be to small, thus spinning to fast. but im not sure. The fan sensor is located at the back of the blower intake, but I put it on a switch also, and I turn it on at 150 deg.
Don't give up on me thanks again for your advise  

what size radiator are you running...    not one of those tiny ones...   something the can handle the amount of heat that motor can put out...

they also make  temp tape stick ons...  so you know how hot each part of the cooling system is getting...  (this is tape/decal that when the temp comes up differnt portions of the tape become readable.....)

have you tried a 195 degree thermostat...  big engine cads would only work with a 195 stat...   there are even 205 degree stats for real trouble makers..  

I agree you might want to upgrade the radiator size. I believe the company Be-Cool makes a four core aluminum radiator which I think would help cool down your car a lot. Also I think that a single fan would help cool down your car more too. Be-Cool makes a fan that pulls over 3200 cfm through the radiator which would cool down an engine powering up to 800 horses.  

this might seem a bit DUH but have you checked to see if the upper radiator hose is collasping or maybe you checked this anyway I have had sim problem and wnet to a Gates hose and problem solved, although i used a four core aluminum radiator w/electric fan and a corvette water pump with a 180 thermostat drilled out... sounds like these guys before me have put you on the right track good luck    

Sorry, I have a be cool 27" core with 2ea. 1" tupes, I've talked to be cool and they said that its rated for 1000 hp I sitting around 700hp. I took 3 deg out of my timing today and i'll run it when the outside temp get to 95 today. which brings up a new ? , should I back out more timing until it gets sluggish then put 1 deg back in? My engine builder locked out the distributor and said to set it at 28 deg. My msb box is a 6btm with the adjustable retard as the boost kicks in. My fuel pump is an aromotive rated at 150 gal and hour, and I've set my pressure at 6 lbs. Would a temp reading of my headers be a gage for my timing, and if so what temp should i see?

ps thanks for all of the advice  

The temperature of the headers can be useful, When the headers heat up the most that means you are getting the best compression and most complete combustion possible. What is your idle ignition timing? I think a good idle ignition timing for you especially with your blower might be 6 degrees btdc up to about 10 degrees btdc, if you go any farther than that you will end up losing all your power that you get from the blower because of the super early ignition of the combustion chamber, in addition to  the msd box that adjusts timing along with the boost of the blower. How much timing retard per boost do you have in the box? if you retard the timing too much you might leave extra air and gasoline in the combustion chamber for the next go round of the crank.  

rick68camaro:
I need help with my 468cu in camaro. In traffic or on the freeway im running about 230 deg. When I stop I boil over. weiand 671, be cool radiator with dual 13" fans , restrictor plate medium size(instead of thermostat)distributer locked out timing 28deg., Holley 750's (2) (not running lean) 3000 stall converter, tried water weter, ran ok in 70 deg days, boil over in 90 deg. days. edelbrock high flow pump, 3" exhaust, 2 1/4 headers. Please help I at a loss.
thanks
Rick

Your best bet is to add an electric water pump into the lower hose as an auxilary pump to boost cooling when in heavy traffic when the mechanical belt driven pump is idling just like the engine! Wire it up to the same switch as the fans through a relay and wire them both direct to the battery so when you turn off a hot engine the fans and the pump will run and cool the engine down evenly - you will never do another head gasket.

PUMP TOO FAST MENTIONAED IN A REPLY IS A  FALLACY

THE "PUMP TOO FAST" LOSE LESS HEAT NOTION IS A FALLACY. I HAVE BEEN DOING R&D FOR 9 YEARS ON SEVERAL RIGS AND HAVE NEVER BEEN ABLE TO GENUINELY PUMP FASTER (LIQUID COOLANT) AND LOSE LESS HEAT. IN ALL CAR ENGINES, WHEN THE MECHANICAL PUMP REACHES CAVITATION SPEED, LIQUID COOLANT TURNS INTO A GASEOUS STATE WHICH IS COMPRESSIBLE,( LIQUID IS NOT) AND  THE REAL FLOW RATE OF LIQUID COOLANT DROPS EVEN THOUGH THE MECHANICAL PUMP  HAS A HIGHER RPM,  AND SO HEAT LOSS DROPS. THEN THE TEMP GOES UP. AND IT ONLY SEEMS LIKE THE FLOW RATE IS TOO FAST, AND THE COOLANT IS SPENDING TOO LITTLE TIME IN THE RADIATOR TO LOSE ITS HEAT ETC. ETC.  

Here's a dumb question but, are the fans turning in the right direction?  

Did you finally get the problem solved because there haven't been any recent posts to this thread.  If you solved the problem I am all ears.  I recently built a blown tall deck (marine tall deck) 525 ci big block for my 68 Camaro. I haven't had it on the street yet because it wants to overheat every time I start it. The first time I fired it the temp rose steadily until I shut if down at 220 degrees which took about 5 minutes. I was running it without a thermostat. I have a CSR electric water pump and I now have a three row aluminum radiator. I just installed a two speed electric fan from Lincoln Mark VIII (sorry I had to try a Ford fan but I am desperate) which is supposed to be the best thing out there. I spent all day making mounting brackets and wiring a switch for both speeds. The fan works great and moves a ton of air yet it still wants to run hot and will get to 220 degrees in about 10 minutes. I have test fired the engine about 7 times while trying something new each time. I went to a bigger radiator, installed a water restrictor (started with the one with the biggest hole and haven't tried the others yet) installed the bigger radiator, added coolant lines from the back of the blower manifold to the thermostat housing to get the water from the back of the block to the front. I tried a 160 degree high flow thermostat too.  After all that I am still having the same problem. Instead of it taking 5 minutes to get hot it now takes 10 minutes. My timing is set to max out at 30 degrees and is all in at 2500 rpm's. Right now I am running an old pair of headers with 1 7/8" primary tubes while I am getting the final tune. I know they are too small but I am running them with the collector open right now. Today when I fired it I used my temp gun and took some interesting readings. Running at 1200 rpm's with no load I saw 900-1000 degrees at the header tubes. That seems way too high to me. Does anyone know what the temp should be? I have pulled all the plugs and I am not showing any idication that I am running lean plus the carbs were setup for the blower.   HELP! Anyone got any ideas?