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What temperature Thermostate in 440?

Started by my73charger, June 15, 2007, 10:13:09 AM

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my73charger

What temp thermostate are you guys running in your 440's?  My 440 runs a little hot even with a bif aluminum radiator.  It is bored 60 over so I assume that is most of the issue.  It will run between 200-210 on the highway.  I was thinking of replacing my current situation, which is basically just a restricter ring with a 195 now that the motor is good and broke in.  I started out runnig a 160 then 180 then tried a 195 and finally went to basically what amounts to a washer that restricts flow. 

Challenger340

Some ideas that may help get you some good answers.

How much compression ratio does your 440 engine have ?

What Fuel ?

Whats your timing at ?

I run a 180 in my 440, stock radiator, no problems.
My total timing is 32 degrees, all in by 3000 rpm with 9.4:1 CR on iron heads, 234 @ 050 Cam.

Only wimps wear Bowties !

my73charger

I am running about the same timing with 10.3.1 compression on iron heads.  I use 91 octane premium fuel

Challenger340

In my opinion, the 10.3:1 C.R. is the problem on the iron heads. The compression ratio is too high for 91 Octane.
Which Iron head casting do you have ?
What Piston are you using ?
Does this engine ping under load at lower rpm's ?

Let me give a description of what I think you are experiencing, if it seems accurate after you read it, then you can plot a course to remedy the situation.

Here goes;
Normally, after you start the engine cold, the temperature steadily increases to almost overheat and stays there. Worse in stop & go traffic with faster rate of temperature climb.

If you drive along at 30 - 35 mph in top gear at "minimal" throttle pedal, just to maintain speed, just above "coast", which gives best ratio of airflow and rad cooling, to low engine rpm's, the engine will maintain, or slowly drop it's temperature ?

Does it maintain a "level" temp without increasing at 30 mph in high gear("D") ?

Only wimps wear Bowties !

my73charger

I am running I believe 352 heads.  One other note I didn't mention is I am now running an electric fan with the aluminum rad.  It does slowly climb and just stays at 200-210 range.   It doens't ping however.  Seems to run excellent actually.  Thanks for the help.

Challenger340

Solid or Hydraulic cam ?

Sometimes, with detonation, just because your not hearing it, doesn't mean it's not there.
At 10.3:1 C.R., Iron heads, there has to be some detonation going on with 91 Octane.

For lack of a better description, and getting to the point, detonation manifests itself in temperature problems, as too much cylinder wall exposure to peak combustion temperatures.
The cylinder walls are the heat sink that absorb the excess BTU's, which overload the cooling system. Thinner 060 over walls also mean less heat sink.

fix;
if you're otherwise happy with the tune, try a Mezziere or CSR electric style water pump, but pricey !
or
try chasing the problem with the tune, which can be frustrating

Geez, I dunno, hope this helps out, just some ideas.

Bob out.
Only wimps wear Bowties !

firefighter3931

Have a look at the plugs to make sure it isn't lean....they should be light brown > tan in color. White or light grey means it's lean. It could very well be just a tuning issue as Bob suggested above.  ;)

You'll have to do a little investigative work to sort it out.  :scope:



Ron
68 Charger R/T "Black Pig" Street/Strip bruiser, 70 Charger R/T 440-6bbl Cruiser. Firecore ignition  authorized dealer ; contact me with your needs

my73charger

Thanks guys!  I will do some homework.

Ghoste

Quote from: Challenger340 on June 15, 2007, 12:41:21 PMSometimes, with detonation, just because your not hearing it, doesn't mean it's not there.

:yesnod: Especially with headers and low restriction exhaust.

my73charger

Ok, I can't believe it, I feel like an idiot cause I knew this, but my lower radiator hose didn't have a spring in it and was colapsing under pressure and causing my running hot.  This happened to me once before.  I put a new hose with a spring in it on with a 180 stat and now it runs about 185-190 degrees.  Also, my plugs are a nice light brown color so I feel confident that I am not running lean at all.  I do have another question though.  A friend of mine that is a racer told me that I should plug the hole in the water pump housing directly below my stat because it will flow better and run even cooler.  He told me that his engine builder told him about it and he runs about 10 degrees cooler than before.  Has anyone here ever heard of this or tried it?