Guest sb400z Posted April 11, 2003 Share Posted April 11, 2003 Before installing my heads I want to make sure i'm not going to crack them. Its getting hotter every day out here in phoenix, and as it stands, the car runs at about 175-185 moving, and when it sits still at a light, it gets up to 210-215ish. That seems warm to me. I have a Griffin aluminum radiator, a 16in fan in front of it, and 2 ten inch fans blowing on the motor, and a stock water pump, not sure on what temp thermostat. When its not over 90 degrees outside, the motor rarely sees over 160 driving and 180 sitting. My questions are 1) How hot is too hot for aluminum heads, and 2) what else could i do to keep it cooler other than a better water pump and vents in the hood (don't like idea of vents, but I can deal with them if they save my heads), both of which I'm planning when money allows. Quote Link to comment Share on other sites More sharing options...
Mudge Posted April 11, 2003 Share Posted April 11, 2003 Thats nothing, LT1s see 229º before the cooling fan even turns on, stock. That is running a bit on the edge though, but thats smog laws for you. Quote Link to comment Share on other sites More sharing options...
80LS1T Posted April 11, 2003 Share Posted April 11, 2003 To me it sounds like you have plenty of cooling power. Are you sure your gauge is accurate? Also I assume your fan for the radiator is electric, what kind is it? Guy Quote Link to comment Share on other sites More sharing options...
Guest sb400z Posted April 11, 2003 Share Posted April 11, 2003 The fans are electric and are from Checker. Not sure about brand though. I have them hooked up to turn on at about 190, but temp still rises steadily. The motor is a 400 so it runs hot anyways. When i turn off the car, its gotten up to over 230 and once or twice up to 250 (once the relay was loose and fans didn't go on, car got over 270 when i shut if off, that was me being dumb though). Quote Link to comment Share on other sites More sharing options...
80LS1T Posted April 11, 2003 Share Posted April 11, 2003 You should get the relay kit that I got from Jegs. You can vary the on temp from 160- 210 degrees F. It is a Perma-Cool product,and here's the part #771-18907. You can also get a second relay to hook up to so that it controls 2 fans(or in my case the fan and the water pump). Although you can only set one temp. The nice thing about this is that even with the key off the fan and pump will run until it goes below whatever temp I set it at! That's the part I like most about it. It is a bit pricey for the 2 relay system but it is worth it in my opinion...$59.99 for the kit and one relay, and if you want to run another fan or pump it's $15.99 for a 30 AMP relay that goes with the first kit. I think you should invest in something like this, so that your pump & fans will run even if the car is off. Guy Quote Link to comment Share on other sites More sharing options...
Tim240z Posted April 11, 2003 Share Posted April 11, 2003 Since you have a 400 block, make sure that you have the correct cooling passage holes in your head gaskets and heads,and make very sure that the cooling system has been well 'burped' to get all of the air out. Tim Quote Link to comment Share on other sites More sharing options...
Mudge Posted April 11, 2003 Share Posted April 11, 2003 250 is getting a bit scary, definately check the suggested items... Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted April 12, 2003 Share Posted April 12, 2003 Ive blown a radiator and hit 267 degrees before I could get it shut down with ALUMINUM heads WITH ZERO RESULTING DAMAGE! your unlikely to damage aluminum heads unles you get really dumb and try to add cold water to a overheated engine. if you start running over 250 degrees because you blow a hose, pull over and let the engine cool to air temp before adding fluid to the cooling system. engines normally run best at about 190-210 degrees so try to get your cooling system to stay in that range while racing, keep in mind a large oil pan volume helps a great deal in taking heat out of the engine Quote Link to comment Share on other sites More sharing options...
Guest sb400z Posted April 12, 2003 Share Posted April 12, 2003 I'm only 20 but I'm not THAT dumb... Back in second grade I had a friend who's older sister put a hot pan under sinkwater to put out a grease fire, resulting in the pan exploding into her face. She learned my lesson for me. I will probably end up getting better fans and an electric pump that will stay on when car shuts off (fans already do). Today after racing a bit with my friend, i shut it off and it got up to 245, went back down real quick when i turned it back on. I will have aluminum rocker arms, so that will keep oil temp down a bit, and the bigger oil pan is a good idea. Thank you. On another note, somebody told me to hook up a reservoir that i keep full to a mister system like you would use on a patio to lower air temperature before it hits the radiator. It would be on a switch that I would turn on when STOPPED. I know they cool the air a LOT, but would it hurt anything? Quote Link to comment Share on other sites More sharing options...
z ya Posted April 12, 2003 Share Posted April 12, 2003 Tim, Whats the best way to "burp " your cooling system?? Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted April 12, 2003 Share Posted April 12, 2003 most engines have thermostats that block coolant flow,untill the engine reachs the designed temp range, a good trick is to drill several 3/16" holes in the perimiter edge allowing a limited amount of coolant to flow at all times and makeing trapped air under the thermostat a non-issue Why Drill Holes in Your Thermostat? I guess the obvious reason is to keep your car cooler therefore controlling KR. However the holes only reduce overall engine temps by about 5 degrees so we have a much more important reason for this. While at the track you open the hood, maybe ice the charger and let the motor cool down between runs. This may bring your coolant temps down to very low levels, which is good however these cool temps may actually slow you down. With the coolant and engine cooled down there is no coolant circulating until the engine temps reach the temp of the Thermostat. This would normally be OK however when you're racing the combustion chambers heat up very quickly. So the coolant around the cylinders and heads might reach 250 degrees before the stat even begins to open. This is very bad and can cause high levels of KR in the back half of the ¼ mile. By drilling the holes in the thermostat you can eliminate this problem because you will always have a small amount of coolant flowing. Quote Link to comment Share on other sites More sharing options...
Tim240z Posted April 12, 2003 Share Posted April 12, 2003 Tim, Whats the best way to "burp " your cooling system?? Jack up the front of the car as high as you can. That makes the radiator cap by far the highest part of the system. That way you much more of a chance of ALL the air 'pockets' in the block/heads burping up to the radiator. Run the engine with the cap off and keep topping off the coolant. When it's completely full, replace the cap. That's about it. It will generally result in an overfull colling system, so expect a little coolant to piss out later. Tim Quote Link to comment Share on other sites More sharing options...
Guest sb400z Posted April 13, 2003 Share Posted April 13, 2003 I've decided to get a CSI electric water pump and connect it to the relay that I have my fans on. They stay on after the car is shut off until whatever temperature I set the dial at is reached. As for the thermostat, what temperature rating do you all recommend? Quote Link to comment Share on other sites More sharing options...
Mudge Posted April 13, 2003 Share Posted April 13, 2003 I'm happy with a 160 thermo, with the climate you live in, thats probably what I would run as well. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 19, 2003 Share Posted April 19, 2003 i am not sure if this will help, but check http://www.rondavisradiators.com. i think that is the correct address. he has an aluminum double fan shroud kit. Quote Link to comment Share on other sites More sharing options...
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