Heating up on the freeway

[GoodysGotaCuda]

Just went to a shrouded electric fan setup on my summit aluminum radiator. 185* on, 170* off. Works great on the street and in traffic. Sticks at about 180*. Once i start on the freeway (70mph = 3700rpm) the temp creaps up to 195* or so according to my autometer. Once i get off the freeway it about stays at that range, almost like it cant cool that extra 15* it just gained back off.

Heres the fan setup. I've tried running on the freeway with the fan manually turned off, and with it running with no change in temp



Anyone think i should make some rubber sheet flaps or something? How can i tell if its lean at that RPM or something? Its got 91/100octane on 9.7:1 CR so it shouldnt be pinging or anything.

Any  is appriciated

[ShelbyDogg]

Goody, once on the highway, you don't even need a fan. Could that shroud be holding in the heat?  My engine used to heat up only on the highway and never around town.  I had to have my radiator "RODDED" out because it was plugged. I went ahead and had a 3 core put onto my stock tanks. (I have the A36, Hemi top)  Check your timing. 

Plus you have that cheby style radiator on there.  There is a reason why Mother Mopar puts their tanks on top and bottom. Is it big enough?

There are 2 ways to check if it's lean:
 1, like racers shut it off at speed and pull the plugs and look at them.
2,  Put in an oxygen sensor like I did and watch it on the computer or guage.

Rob

[GoodysGotaCuda]

Goody, once on the highway, you don't even need a fan. Could that shroud be holding in the heat?  My engine used to heat up only on the highway and never around town.  I had to have my radiator "RODDED" out because it was plugged. I went ahead and had a 3 core put onto my stock tanks. (I have the A36, Hemi top)  Check your timing. 

Plus you have that cheby style radiator on there.  There is a reason why Mother Mopar puts their tanks on top and bottom. Is it big enough?

There are 2 ways to check if it's lean:
 1, like racers shut it off at speed and pull the plugs and look at them.
2,  Put in an oxygen sensor like I did and watch it on the computer or guage.

Rob

As mentioned i've ran on the freeway with the fan on and off with no change in temperature..It is a aluminum radiator and im sure its big enough.  It seems to have started getting warmer on the freeway since the shroud...but also the outside temp has shot up lately so i cant pinpoint that as being the problem.

I'll try and kill the motor at cruising speed tomorrow and check the plugs and see how they are. It hasn't been an issue until the weather has gotten hot and/or i added the shroud.

[Chryco Psycho]

the fan may simply be blocking too much air flow 

[GoodysGotaCuda]

the fan may simply be blocking too much air flow 

was just looking out at it, its really not all that restrictive looking. So what would the cure be short of changing fans (just bought it). Cutting some holes in the shroud and using some rubber sheet thats attached at the top which would open up at higher mph? 

[GoodysGotaCuda]

Ok heres a picture oh the fan setup. Between the radiator core, and the shroud there is about a inch/inch anda half of space inbetween there or so.

[fantum]

As mentioned above, when driving at highway speeds, you shouldn't have an overheating problem.  If this wasn't a problem before you went to the electric fan I would be inclined to think you may have a problem with the fan.  Is there, by chance, some way that you may have wired it to run backward?  That would cause a lot of the problems you are relating above.

Good luck,

fantum

[GoodysGotaCuda]

As mentioned above, when driving at highway speeds, you shouldn't have an overheating problem.  If this wasn't a problem before you went to the electric fan I would be inclined to think you may have a problem with the fan.  Is there, by chance, some way that you may have wired it to run backward?  That would cause a lot of the problems you are relating above.

Good luck,

fantum

I put the fan in about a week ago or so. When i first had it in there didnt seem to be much of an issue. Freeway or Street. Outside temp was low 80s or so, temp never moved over 180*. Now this week were up to mid 90s  and I'm seeing an issue. On my way to work today (94* outside temp)it got up to 195* or so as usual (in the heat) on the freeway. And on the way home Tonight (about 82* outside) and it didnt move over 180*...with the same freeway traveled. So i'm guessing its having a issue keeping up when its hot out but i cant pin-point it.

Makes me want to think that possibly its the motors fault. Would higher outside temp make it run lean at all? Our gas here sucks and i do run a 91/100octane mix (9.7:1 cr)...i did cut back some on the 100 lately, i will bump the mix back up tomorrow when i go get gas just to make sure theres no issue there.

Now, did that post make any sense at all?  because im not sure it did. I may be gettin a little desparate because this is bugging me now 

Thanks!

Edit: and the fan is defiantely pulling air. Not backwards. If it was, i bet id have some serious cooling issues sitting in traffic at 95* outside. Thanks!

[ShelbyDogg]

How long does it take to get down to normal temp after you get off the highway.  What temp Thermostat do you run? 160 degree?     195 isn't too bad, it's the fact that you said that it doesn't cool down quickly after getting off the highway.  Time the cool down with and without the hood popped up to it's safety latch.   There is alot of heat in there that can't get out.
Rob

[Bullitt-]

I've seen a product  ?water wetter?  that claims to lower temps. several degrees. Avail at local parts house, would be a cheep fix if it works.
Also an item to add to the pump that stops cavitation,
http://store.summitracing.com/partdetail.asp?part=BRA%2D4375%2D07&N=%2D120574+115&autoview=sku
re: rich, Back in the day on a hot trip to FL I could run 55 just fine but at 60+ the temp would rise. I figured the mech. secondaries were staring to open, adding fuel, which would make things richer & add heat. Never had any other overheating issues.

[GoodysGotaCuda]

How long does it take to get down to normal temp after you get off the highway.  What temp Thermostat do you run? 160 degree?     195 isn't too bad, it's the fact that you said that it doesn't cool down quickly after getting off the highway.  Time the cool down with and without the hood popped up to it's safety latch.   There is alot of heat in there that can't get out.
Rob

Its a 160degree. And 195 isnt tooooo bad i know, it just didn't do it before so theres a reason why its doing it now.

I've seen a product  ?water wetter?  that claims to lower temps. several degrees. Avail at local parts house, would be a cheep fix if it works.
Also an item to add to the pump that stops cavitation,
http://store.summitracing.com/partdetail.asp?part=BRA%2D4375%2D07&N=%2D120574+115&autoview=sku
re: rich, Back in the day on a hot trip to FL I could run 55 just fine but at 60+ the temp would rise. I figured the mech. secondaries were staring to open, adding fuel, which would make things richer & add heat. Never had any other overheating issues.

I was thinking of water wetter today, ill give that a shot. And my pump does have a cavitation plate on it already. 

[GoodysGotaCuda]

Any other suggestions? Issue doesn't seem to be consistant. I haven't been able to track it down to it just does it when _______. Really annoying  Anymore suggestions i could try 

[dlrogers]

Hiya Goody
Have discovered that my 383 has a gradual rise in temp once I'm out on the highway - I drove over a hundred miles in a que of traffic heading home from the city one day and once I got clear road and was able to speed up, my old girl began to heat up. Same thing happened a few weeks later. I took the inserts out of the hood before the next trip and the temp was better - not excellent but better. IMO its the airflow affecting the temp in my setup and I think it could be in yours too especially if the only thing that has changed is the way the air is controlled under your hood - have you tried without the shroud?
Best of luck
David

[GoodysGotaCuda]

Hiya Goody
Have discovered that my 383 has a gradual rise in temp once I'm out on the highway - I drove over a hundred miles in a que of traffic heading home from the city one day and once I got clear road and was able to speed up, my old girl began to heat up. Same thing happened a few weeks later. I took the inserts out of the hood before the next trip and the temp was better - not excellent but better. IMO its the airflow affecting the temp in my setup and I think it could be in yours too especially if the only thing that has changed is the way the air is controlled under your hood - have you tried without the shroud?
Best of luck
David

I'm thinking cutting some holes in the shroud and using some rubber sheet that will flip open at highway speeds will help out. i cant run it without the shroud, its all one piece or no fan at all...unless i converted back to clutch which i wouldnt wanna do if i didnt have to. I have a flat hood right now, and a 6pack hood that needs some work in the garage i need to work on getting on there, that fresh air would help circulate things, but i dont think thats the solution...i need more air through that radiator 

[Bullitt-]

Goody, as someone suggested, try changing back to what you had before the problems surfaced & see if they go away.

Also has anyone suggested a "high flow" thermostat?  I see Molodon purports theirs lets more coolant circulate