Engine Is My Temperature Normal

[91BlckGT]

So I'm doing some final shakedown drives after a multi-month rebuild. It's now a fully built H/C/I with AFR heads.

I had to replace the TFI module due to heat soak, and relocated it to the fenderwell. I did some surface guage temperature tests tonight after driving it to temperature for about 30 minutes. Here's where the temps fell:

Dash: 'M' in normal. (Around ~200 degrees I think)
Distributor Surface: ~143 degrees F.
Head Surface Temp: ~197 degree F.

However, after it was sitting idle for 2 min, I turned the lights on and temp gauge went up to the top. I'm thinking I still have some cooling isues. The fan and fan clutch are stock, but the radiator and water pump are aftermarket.

Looking at the numbers, I think it's time for a 180 degree thermostat, and maybe swap out the fan for an twin electric model (the alt is a 130amp upgrade). Last ditch is replace the radiator. It's about 13 years old now.

Thoughts?

 

[90sickfox]

What was the temp of the heads when the gauge went up ? A bad ground will cause the same thing to happen with factory gauges. Our temp sensors use the block for ground. Do you have the ground running from lower intake to the firewall ?

 

[General karthief]

Clearify some things, you turned the lights on and gauge ' went to the top', I'm gonna guess that is where the temp gauge was reading at the top when you turned the lights on, if the temp gauge moved to the top when you lit it up would indicate an electrical issue. So I'm go'n with it was there when you lit it up.
Now give some info, make model mods
13 year old radiator needs attention, more so if it sat empty for a period of time. Ford gauges are not accurate, they only hint at the temp. Get a quality gauge, for under hood and compare it to your stock gauge, that will give you an idea where its at compared to the aftermaket. You don't need an electric fan, stock clutch fan is very effective with the shroud. A 190 or 195 degree thermostat is needed for efi. Test the thermostat before you install, cheap ones are just that, cheap. That is my advice, somebody here I'm sure can add to it.

 

[General karthief]

Note: lazer beam surface gauges are great, but understand they are not see all tell all. Great tools though,
Example, my rad runs 180 all over except the top corner at the hose is 190, the heads run 200, lower hose is 170, intake is 200 thermostat housing is 200 these fluctuate
3 core electric fan 90degree day

 

[91BlckGT]

The engine was off when the gauge went up, that was the first time I ever saw that. The radiator did sit empty for 5 months during the engine rebuild. The lengthy story of the build is here:
http://www.stangnet.com/mustang-forums/threads/91blckgts-about-time-progress-thread.893470/

I was still running the stock temp termostat. I wouldn't say the car is overheating, just running hotter than it did before the head/cam/valvetrain swap. Just not sure if I should be worried. I"m still breaking it in, and the car runs fine (stalls occasionally) so I still have some gremlins to sort out, but I think that's mostly because I haven't locked in the tune. I need to get some better gauges.

 

[General karthief]

I agree on good gauges, when you turned off the engine you get heat soak, that was the spike it temp you witnessed, normal, I really saw nothing alaming in your post and I did not read you build yet, I promise I will.
I have 3 core radiator not sure I like it, temp fluctuates I also have an electric fan, not sure if I like that either, underdive pullies, well I don't have to tell you 'bout those, the fan and pullies are cool but I will be probably going back to clutch fan and stock pullies soon.
How did the temp do driving steady down the road, consistent, no fluctuations?
I also have a meat thermometer stuck between the rad and electric fan shroud, that is pretty accurate.