SB 350 Running Hot

[Seth]

I have just dealt with my rig running hot for a couple of years now. I an going to make an effort to correct it now.

When I am moving around 20 she is fine, 180 steady. But as you know, you end up going around 5 to 0. Even with an electric fan running full time she climbs steadily to 240 when I stop and let her cool off.

I am going to flush the system and replace the thermostat and fluid to start.

My question is can I, should I, run a 170 thermostat on a sb 350. Any potential problems for 170, 160 or lower etc. She is injected.

Or am I not looking at the right side of the equation? Bigger fan maybe.. I am far from a engine guru. I just replace parts as they break. So be kind if this is a silly question.

 

[JKS]

What fan are you currently running? Sounds to me like you need more air flow. I was having the same problems with my Cruiser (TBI 350) and I ended up going with an aluminum radiator and a two speed fan off of a Ford Escort. It stays around 200 - 210 now.

Might also look at hood louvers and or cutting fender wells to improve air circulation at low speed.

Also, putting in a lower temperature thermostat will not help with an overheating problem.

 

[AINT SKEERED]

Also, putting in a lower temperature thermostat will not help with an overheating problem.

x2.. You need another fan, or a bigger one.

 

[waynehartwig]

x3 And since it's injected, if you go too low of temp on the thermostat, you could cause other problems, like running rich or failing emissions. I wouldn't put any lower than a 180* in there. A 195* might level out the temp, so you don't have such a huge swing, but it might not resolve your overheating.

Next time you drive it, turn your heater on full blast and see if that makes any difference with the temperature. Also, if your temp is high, your heater should be pumping out really high temps as opposed to if you are running at 180*. If it doesn't, then you could have a bad water pump.

 

[JKS]

Might not hurt to double check your ignition timing. If the initial advance is not set right then it can make the engine run a little hotter than normal. I doubt that this is the cause of the overheating, but it can add too it.

 

[mbryson]

more fan..... 180* is as low as I'd go with the TBI setup. If it's TPI, I think they like the 195* but I can't remember why I think that. Go snag a Taurus fan from the junkyard.

 

[Seth]

Thanks everyone for your quick responses.

I have a couple photos so you can see what I am dealing with. The elec fan is small, but I am hard pressed to get something larger in there. I am wondering if I can divert the heat form the heater outside during the warm months. If the temp drops when I run the heater that is.

We will see. The Summer Convention in Richfield is this next weekend and that will be the first time I have to test the theory.

 

[Jinx]

I recently had this same problem

two things to check.
1st-after putting a shroud, bigger fan, flushing system, etc. I changed to thermostat to the stock one application, 195* tpi 350 and that seemed to really help keep things in balance.

2nd- When I was still showing really hot and I couldn't figure anything else out- I borrowed a laser point thermostat from a buddy at a shop and found my engine wasn't running hot as I thought it was. It turned out to be a lose ground on the gauge that threw it off 25*

hope this helps.

 

[James K]

I was thinking the same as Jinx, are you sure the guage is reading correctly?

I had an electeic autometer water temp guage and never seemed to work right. So thus I thought it was always running hot. It turns out the guage was bad. Put a mechenical autometer guage in and it runs up to 205 and then kicks the fans on and runs it back down to 180.

 

[Seth]

I will check on that too. I have had intermittent trouble starting her lately, so I am going to have a few things checked out this week. I will check the ground tomorrow morning.

When she was getting hot, we would spray water on the radiator and the temp would come back down, would that still be true if it is a gage issue?

 

[Jinx]

I will check on that too. I have had intermittent trouble starting her lately, so I am going to have a few things checked out this week. I will check the ground tomorrow morning.

When she was getting hot, we would spray water on the radiator and the temp would come back down, would that still be true if it is a gage issue?

if the gauge is bad or ground not secure, spraying water would still bring the temp down.

good luck.

 

[Bart]

This is all good information. I'll just add a bit more. You need to be around 195 to get the computer into the closed loop, so a lower temp thermostat won't help.

Have you checked your fan clutch? It may be going bad and not engaging when you need it.

Is there anywhere else to mount the aux cooler that's on the top right of your radiator? That's restricting air flow.

Don't replace the mechanical fan with an electric if you can help it, even a Taurus fan.

If you could find a way to add a couple inches onto the shroud lip area around the fan, you'd create more vacuum and air flow.

 

[Milner]

One more thing to add.
Make sure the shroud does not cover more than 1/2 the depth of the fan. If it does, the hot air just gets stuck and circulates inside the shroud....Seen it many times.