stardate 2020.0629.1400 -
gonna have a lot of parts for sale at the car show swap meet this year if it isnt covid-ed out.
First things first - I asked the forum for a year if the water pump can be installed backwards/ upside down, and no one ever answered. Well, the answer is YES, the water pump is typically directional, and oriented in its mounting position. It may or may not be marked TOP, but if there is a weep hole, that must point downward towards the ground. and yes mine was upside down. so that was pinching the loaf. so that water pump orientation was corrected.
uninstalled the cold-case 2x 12" electric fans + shroud kit.
installed hayden fan clutch and derale 18" 6 sided fan.
here are both the hayden 2747 (long neck) and the hayden 2947 (short neck) heavy duty, thermal fan clutches. derale 18" clutch fan mounted to the 2747 in pic.
takes 5/16-18 bolts grade 5 minimum 5/8" long all the way around both ends so 8 - 4 for the fan and 4 for the pump.
I also went back to an OEM 440 large radiator shroud.
Installed a 160* thermostat with a 1/8" drill hole in it.
I tried the hayden 2747 and it fit the car but the fan blades were too deep into the shroud.
It ran cooler longer than the electric fan kit, but still went hot sitting idle in the driveway.
It is beyond critical the fan:shroud placement. If the fan is totally inside the shroud, or more than halfway out, it will not cool at its best possible rate, and may even hinder cooling with improper airflow thru the radiator. It really is the difference between being able to operate the car or not, if you are not properly cooling the engine. The blades also need a certain pitch to them. The blades also need aprox 1" of space gap between the fan blade edge and the shroud circle. The fan to shroud needs to be centered. The fan blade length should not extend beyond the radiator frame. You need to seal up any gaps between the radiator and frame/body/hood/etc. The shroud should encompass the entire face of the radiator. The fan clutch needs to be aprox 1" - 1 1/2" off the face of the radiator. there are a thousand things to study.
So $70 more dollars and 2 days later summit sent me the shorty hayden 2947.
mounting the blade to the clutch is almost a press on thing the tolerances are that tight, plus the layer of black powdercoat paint on the fan - it was a good fit. Start your bolts and tighten criss-cross evenly and pull the blade down onto the clutch body. 15 - 18 lbs. blue juice on threads. grade 5 or 8 bolts with tooth heads or same-grade lock washers.
the bolts for clutch to pump, the ones that go thru the pulley - they must be grade 5 or 8, 5/8" long, and short bolt head, or they wont fit. or you have to use studs. the clearance is nil to start these bolts it was pretty exact. i had to walk away a couple of times. same same blue thread locker and lock washers. hayden says position the split of the washer over the bolt channel.
so here we are now today, with the proper amount of suction. I drove over an hour in city traffic in the mid 90s sunny day today and didnt start stumbling out or go past 210 at all ever, so I can maybe at least make it to the whataburger car nite now.