My new 521 is running a little warm. Runs ok until going up hills. Temp. goes from 180 to 210 going up a long slow driveway and then boils over. What is the optimum temp? It has a new 4 core rad. and a high flow water pump. I put a new fan clutch on but still do not here the big roar of it kicking in. Any ideas?

 

do you have a fan shroud on it? If not you really need to get one on there.

 

Yes, original shroud.

 

If its boiling and you don't hear the fan clutch roar there might be a problem. Just because its new doesn't mean it can't be bad. I don't know if they still do it but we use to check out the fan clutches by taking a piece of cardboard and put it in front of the radiator. We would cut out a circle the same size as the fan clutch hub and position it right in front of the fan hub. This way the radiator was blocked but the fan clutch would get the full blast of the heat coming through the radiator. This way the engine would warm up quick and the fan clutch would get all of the heat and really roar. You have a problem if the clutch is not roaring when that engine gets hot. Get the engine up to 220 and shut it off. If the fan clutch spins freely its no good. Also I put a six blade fan on mine and it helped my 460 cool better. Stay away from flex fans they aren't worth a crap. I found this out the hard way

 

it doesn't get hot idling for an extended time?maybe check to see if timing is slow.are you running a t-stat?

 

Problem solved! 3rd new fan clutch finally works. And i had my overflow hose hooked up wrong. Now it runs at 180 and in traffic on a hot day it might creep up to 190.

 

Glad to hear the problem is solved. This is a lesson learned, just because its new doesn't mean its good. I always double and triple check anything I buy, new or not.

 

Heck, boiling of water doesn't start until 212 degrees. Are you sure your temp gauge is right. My fan Clutch doesn't lock up until 220 degrees. When pulling my trailer I run 210 pulling a long hill it will go to 220 and hold because the clutch locks up. I have a 460 new water pump, new radiator, hoses, belts, thermo, fan clutch & etc. I ran a little cooler about 205-210 before I recurved the dist. set it up for 5000 ft.

 

Hey kermmydog put a 15lb cap on that radiator and the water in you radiator wont boil until around 260

My 460 will get up around 210 on long grades like the Baker Grade. I never hear the fan clutch cut in. It never gets over 190 without the trailer in tow.

 

get rid of the clutch fan! when that thing comes apart its really gonna cost ya then.