When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Robert, IMO the 160 t-stat will slow down the runaway train. But it will not solve the problem.
You said the the temp goes from 190 to 170 through the radiator. What does it get up too?
Personally, I suspect the fan or fan air flow.... especially since it cools going down the road.
One other thought, have you tried pulling some timing out, and or , adding some fuel, ie its lean? Long, shot, but wanted to throw that out there.
Not a long shot at all....in fact I was trying to measure the exhaust headers with the IR gun. They were running around 390 deg at idle, so I don't think it's running lean. Also, the cooling problem is at idle...how lean could it be running at idle and generate that much more heat?
One other thought I have....With the front end relo, I now have about 2.75" between the water pump pulley and the radiator. Thinking about adding a flex fan (no clutch) and a shroud ALONG with the electric fan. I know it'll scab some power, but I've got plenty to spare at 400 HP....thoughts?
Last edited by robertmee; Jul 19, 2017 at 06:07 PM.
If the problem is only at slow speed or idle then I would deduce its an airflow issue. A shroud should help with that and making sure the fan works. The 180 thermostat would also help.
If the problem is only at slow speed or idle then I would deduce its an airflow issue. A shroud should help with that and making sure the fan works. The 180 thermostat would also help.
it's a pusher fan in front of radiator...everyrhing I've read says no shroud.
Again, can't add much, except to add that a 160* thermostat is way too low for these trucks. I know yours isn't stock anymore and all that, but it's still a Magnum engine. The lowest you should go is 180* unless you want to hear ping pong ***** from predetonation. 160* should only be used if you're running boost. Which I know this truck isn't.
If you are overheating, a 160 vs 190 will not prevent it. A thermostat controls the min. operating temp. not the max. temp. If the truck is 200 degrees, a 190 will be just as open as a 160.
But the 160 will open sooner and start the cooling process.... So it will take a little longer to actually overheat. That is why I called it, slowing down the runaway train.
I have a intrepid fan I purchased a few years ago, Could give you measurments if you like. basic measurments are 26x15 motor thickness is 3.5 in.
I wonder if you could mount this inside the engine bay and the motors would straddle the water pump pulley? Its thinner in the middle. Again, I can send you pictures and measurements if you like.
Also, personally if the truck was mine, I would be running a 160 regardless. A cooler motor actually pings less then a hot motor. IMO the 190's are used for emissions and a carbed motor like yours would be better served running cooler. But again, that is just my opinion.
If I understand correctly, with the new radiator, going down the highway, you are cooling ok.
That being said, I dont think overheating at idle has anything to do with your motor making 400 hp.
Just for grins, here is something I would try. With the hood up, reverse the fan direction so its pulling instead of pushing. If it will remain cool, then that would verify it is a air flow problem.. Of course you cannot drive it pulling air back towards the grill....
But fans are much more efficient pulling then pushing.
I am going to try again to send you the shelby fan picture. Keep in mind these fans worked with AC so this design should surely cool yours at idle.
If you are overheating, a 160 vs 190 will not prevent it. A thermostat controls the min. operating temp. not the max. temp. If the truck is 200 degrees, a 190 will be just as open as a 160.
But the 160 will open sooner and start the cooling process.... So it will take a little longer to actually overheat. That is why I called it, slowing down the runaway train.
I have a intrepid fan I purchased a few years ago, Could give you measurments if you like. basic measurments are 26x15 motor thickness is 3.5 in.
I wonder if you could mount this inside the engine bay and the motors would straddle the water pump pulley? Its thinner in the middle. Again, I can send you pictures and measurements if you like.
Also, personally if the truck was mine, I would be running a 160 regardless. A cooler motor actually pings less then a hot motor. IMO the 190's are used for emissions and a carbed motor like yours would be better served running cooler. But again, that is just my opinion.
If I understand correctly, with the new radiator, going down the highway, you are cooling ok.
That being said, I dont think overheating at idle has anything to do with your motor making 400 hp.
Just for grins, here is something I would try. With the hood up, reverse the fan direction so its pulling instead of pushing. If it will remain cool, then that would verify it is a air flow problem.. Of course you cannot drive it pulling air back towards the grill....
But fans are much more efficient pulling then pushing.
I am going to try again to send you the shelby fan picture. Keep in mind these fans worked with AC so this design should surely cool yours at idle.
Certainly those shelby fans have MUCH more coverage than my single perma-cool.
BTW, those shelby fans are SPAL 30100365. Still available as single units. The part that's not available is that nice frame that bolts into the radiator core.
If a puller fan is more efficient, I still think my idea of a flex fan bolted to the water pump pulley has merit. It'd certainly be the easiest and cheapest thing to try.
Its been awhile since I copied those pictures, but I think it was from a article showing a person using the spal fans to replace the factory fan, and again, from memory, they claimed better air flow.
Just something close to what you are doing, but some of the corvettes in the mid to late 80's did something similar to what you are suggesting. They used a single electric fan pulling through the radiator, but had a pusher fan out front. Are you going to be able to fit a shroud in there?
Its been awhile since I copied those pictures, but I think it was from a article showing a person using the spal fans to replace the factory fan, and again, from memory, they claimed better air flow.
Just something close to what you are doing, but some of the corvettes in the mid to late 80's did something similar to what you are suggesting. They used a single electric fan pulling through the radiator, but had a pusher fan out front. Are you going to be able to fit a shroud in there?
I could fit a shroud if necessary...would have to custom fab up something from aluminum.
Could you please give me some spec on the intrepid fan you mentioned? You said it was 26"x15". Every intrepid fan I can find for model years 98-2003 (which is what everyone seems to use) is 34" wide (two 15" fans) and no way that would fit our trucks.
Last edited by robertmee; Jul 20, 2017 at 02:46 PM.
