Quote:
Originally Posted by RICK LAKE
DocDirk Doc you shouldn't need anything more than a 15# cap. What thermostat are you running in the motor? Run a 180 temp would be about the best for your area. Do you have a shroud on the coolant fan? You want to pull as much air through the rad to control and lower the coolant temp. Water pump, who's do you have? Here's the best one, are you running UNDER DRIVE PULLEYS???  from March?? They don't spin the water pump over fast enough to cool the motor and control heat. If the car sat for a couple of months you might want to replace the thermostat first. Drill a couple of 1/8" holes in the edge of the thermostat to help remove air from the coolant system. Make sure that is not alot of debrie in the fins on the radiator. One more check is to make sure that the rad has no cool spots. This could mean that the tubes are not flowing. Anything more than 16# cap you are looking at possible loosing on a hose to this much pressure. How low has the motor been built and running. Do you hear and bubbling or gruging sound coming from the motor when hot? Before you start playing with anything, get a infrared temp gun and check to see what the coolant temps are around the motor and rad. It is VERY POSSIBLE that your coolant gauage could be 10-20 degrees off and there is no problem. Let's do the basics first before we go hunting for a nightmare. This has happened before to other guys here. Rick L. Ps you have PM. |
Rick,
My current radiator cap is 16#. I'm running a 180 top quality thermostat but have not drilled holes in it yet. I saw one from Speedway that has them already. My engine is relatively new, less than 15 hours on it. There is no debris on the radiator. I'll check for radiator cool spots. I shall get the infrared temp gun as I want to check across my tires for best inflation pressure too. No bubbling or other strange sounds from the motor when it's hot that I can tell (lumpy cam and loud exhaust excluded). I have relocated my temp gauge to the block because of a complicated setup with the surge tank line to the thermostat housing and I'm told by some that's fine and by others it's reading too low there. My radiator is shrouded to the fan but not in front from the opening of the car. The water pump is rated 20% over stock output and it's OVERdriven by a pulley smaller than the crank pulley. Up until the hot weather spell the car was running at a steady 185 with a 180 thermostat so I figured the temp gauge was probably accurate. Some have suggested I'm pushing too much water through the system. I'm soon going to reroute the fill hose exiting the surge tank away from the intake side of the radiator to the low pressure side of the water pump as it may currently be providing a way for the radiator to be partially bypassed through the surge tank:
. I"m sure I'll have this all sorted out and enjoying trouble-free worry-free driving by 2012
Thanks for your thoughtful analysis!
Regards,
Dirk