Optimum coolant temp???

RIO5.0

15 Year Member
Feb 16, 2001
6,892
7
128
N.H.
What would you consider a optimum temp???? My new 331 has a hard time getting to 160 - 170 this time of year.

I noticed my oil separator had a milky looking oil in it today?? I cleaned it out a month or so ago and hadn't driven it since. I'm thinking my motor temp is to low and its maybe getting condesation?? In the dead of Summer Id see 190 sometimes and the oil separator was normal looking.

Today I drove 10 miles before my Autometer gage even came to life...showed 170 and finally the thermo opened and it went to 155. Factory gage is staying on the N for my 16 mile trip to work.

My thinking is its running to cold??? Im running a 180 calibrated stat with a CR racing aluminum radiator and FRPP water pump.
 
  • Sponsors (?)


I believe around 200-205 is about optimum for fuel economy, emissions, and longevity.

Big radiators are great in the summer heat, but suck when the weather turns cold. Try taking a piece of cardboard box and sliding it between the radiator and condensor to block off part of the airflow. Start off about half of the radiator and test drive then trim till it's at the temp you want. Kind of how you see diesel trucks and school busses in the cold winter with a cover over their radiators that snaps closed.

I've seen milky oil before on cars that are always driven for short periods and not able to heat up to temp to burn off the condensation. That is probably your problem too.
 
You would expect to see an operating temp at least close to the T-stat value. I suspect that your T-stat may not be closing fully or has faulted to a partially open position.
 
It should at least run at 180-190. That's where my 347 ran but never once got over 195 ever. I kinda had the same thing, I thought it ran too cool for Florida summers but 185 is optimal. I'd change your stat and if still it's running cool than install the 192 stat.

Posted these pics in the radiator thread but tells the tail of my temp during the summer.
ClockPod2.jpg
 

Attachments

  • ClockPod2.jpg
    ClockPod2.jpg
    50.6 KB · Views: 105
Thanks for the input...I knew the freaking thing was to cold. A first when I started running this motor I was freaking after seeing the separator...That milky look had me thinking something aint right here and my new motor has issues....:(

Its about time to put it away but I'm def gonna throw a 192 in it to get it up to decent heat. The stat thats in it is a new Mr Gasket 180 +/- 2deg.
 
Since you watch the gauge carefully Andy, blocking part of the radiator (with cardboard, etc) would also work (it helps with wintertime start ups/idle sessions if you do those too).
 
What would you consider a optimum temp???? My new 331 has a hard time getting to 160 - 170 this time of year.

The 5.0 is meant to run between 192*-208*F. Since you have aluminum heads, the engine will be more efficient at the higher end of that range so you'd be well advised to go for a 195* t'stat (or similar rating).
 
The 5.0 is meant to run between 192*-208*F. Since you have aluminum heads, the engine will be more efficient at the higher end of that range so you'd be well advised to go for a 195* t'stat (or similar rating).

Ya its makes me wonder how it'll run when up to temp as most of the time its
running to dang low.
It does run strong tho... the other nite I was beatin on it some under some under passes and she still runs pretty stout and sounds badass....:nice:
 
178-185 is optimal for our cars at the track for all out speed.

This is fact. 500+ passes to back it up. These cars slow down quite a bit at 200 degrees.

my 95 would consistently lose 1.5-2 mph in trap speed once it was around 200 degrees.


I also only got the dreaded 95 pinging with e7s when the car was 200+ Car was always run on premium. and 14* timing while on stock heads.
 
I might have 'read' it wrong but it sounded to me like Andy was concerned with longevity, not 1/4 mile performance. This is a sunny weather toy for him, not a dedicated track car.
And thus, I'd want coolant temps (and oil temps) to be warm enough to flash contaminates.

I agree that for a tracker, cooler is the way to go.
 
These cars slow down quite a bit at 200 degrees.

my 95 would consistently lose 1.5-2 mph in trap speed once it was around 200 degrees.


That could also be due to heat soak into the intake causing the intake air temp to be warmer, not necessarily because the block or coolant temp is too hot.
 
I might have 'read' it wrong but it sounded to me like Andy was concerned with longevity, not 1/4 mile performance. This is a sunny weather toy for him, not a dedicated track car.
And thus, I'd want coolant temps (and oil temps) to be warm enough to flash contaminates.

I agree that for a tracker, cooler is the way to go.

I don't know about you, I prefer not to ping down the road while daily driving. I'd say thats better for "longevity." :D

I put up to 30,000/year on my car while commuting/ being a track rat while doing a fair amount of testing, documenting, and fine tuning.

Oil at warm operating conditions and coolant around 180 was always ideal for my car. I know where you guys are going and I do realize there such a thing as too cold, especially since some cars can get stuck in open loop. 180-85 is not too cold.

That could also be due to heat soak into the intake causing the intake air temp to be warmer, not necessarily because the block or coolant temp is too hot.

do you realize how much the air in the intake would actually have to be heated to drop MPH 2 mph?

Thats a highly doubtful conclusion.

of course heat soak comes into play... thats why the car runs best at 180:track:
 
Open loop and closed loop are a function of time (O2 light-off), not ECT readings.

Andy has a fresh mill with aluminum heads. With no carbon build up and a nice tune, he should not be pinging.


Since you're pretty adamant about this, I am curious - what were your oil temps at when your coolant was at 180*F, and how did your UOA's look?
 
I did not track oil temps. I was on a fresh 302 built by D&D with pre 92 OE TRW forged pistons and e7s that had been hot tanked due to a seated valve.

If you want to break it down to me and explain to me the advantage of running 200 versus 180 and how it is better, I am all ears. Please provide any evidence or experience other than "its what ford intended" or "its what the parameters of the stock computer were set for by ford engineers." I don't think has much weight. There are a lot of engineers out there, being an engineer for a major company does not mean your design is good and the most efficient.

Also, sorry about that smiley, I used the wrong one and wasn't trying to tell you to shut up.
 
My goal was to reply to Andy's question and then question any information I felt was not tailored for his situation. I don't have time to pull up research to support the general consensus on this thread, nor debate optimal engine temps for engine longevity (which differ from those for efficiency, which differ from those for most HP). Much info is available on the web if you're interested. If you feel like providing evidence to support your stance, we'll gladly read it.
 
I have provided facts and evidence, I am sorry your consensus is not enough for me to go research something that it is your hands to prove. I answered his question, which no where referenced "longevity."

There could be other issues at hand here.

What part throttle timing curve are you using for a timing base? A leaner car will heat up faster.
Have you tested your stat to see when it opens and closes or if it is stuck open?
When do you have your low speed fan set to kick in?

Once I got my aftermarket radiator,
I rarely ran the fan ever in the winter. Unless idling for long periods of time in traffic. This allowed the car to warm up much more quickly to 180.