I have a restored 74 Challenger with 440/6, the engine was rebuilt due to a cam bearing issue. The engine is a mild build, 10 to 1 compression, 3"TTI headers, 3" exhaust, aluminum heads, mild cam, new radiator(4 row, 26 inch), 727 3 speed auto, MSD ignition box, 3:23 ratio. The engine runs great, starts right up every time however when in city driving it runs warm, warmer than I'd like to see on the temp gauge. It also seems to run rich to me (slight smell of gas when idling). If the center carb is set to rich will this cause the engine to run hotter? If so, can I make small adjustments to the carb to lean it out? What screw do I turn, which direction? I'm no carb expert so any pointers and pictures would be great. The car is currently in storage as I work overseas but I want to have information available for when I get home so I can make the correct adjustments. Thanks for the help.

there is a 6 pack tuning manifesto on here. Assuming your pulley ratio is not way too slow, then you need more airflow: MP thermal clutch fan or a basic rigid fan (with the most blades) spaced properly into a schroud (~1/2 way in). EDIT what temp is it running at & I would confirm that the gauge is showing a true reading.

Before we go running off into the wild blue yonder, other than the not so accurate stock gauge reading "warmer than I like to see", what makes you think there is a problem with the vehicle?

I remember that "wild blue yonder."

Exactly. every big block mopar I've had felt like they radiated A LOT of heat, but they all ran fine on the temp range.

We are gonning to need more info.

What kind of heads are you running? Do they have heat risers in the head? If not then you HAVE to wire the auto choke open and not use it because it won't work right without heat risers in the head. If you don't wire the choke open then it will run rich at idle because the choke will be partially on.

Tell us more about your cooling system...

What exactly is the temp, with a know temp gauge, or an inferred thermometer looking at the thermostat housing.

SC, I was just going to settle in for another episode of " moparts chase your tail" and you had to ruin it

And to Merlin, unfortunately with your being overseas there is little we will be able to help with until you are stateside with the car.
I would suggest tackling the issues one at a time unless one likes running off into the wild blue yonder
The most accurate method of temperature measurement is achieved with a digital meter and thermocouple probe. possibly you can obtain one while waiting

I agree--before you do ANYTHING else get a good mechanical temp gauge (or IR thermometer). The factory gauges don't tell you anything meaningful.

Nothing is worse than working to solve a problem that you aren't even sure you have.

And if you DO have a high temp problem, you will need a good gauge to track your improvements as you make changes.

I bet it'd run hotter in Riyadh!

Seriously, it sounds like guys are discounting your issue but they are mostly speaking from experience. Factory gauges can be quite a ways off.
It sounds like you have a big enough radiator if you can get air to flow through it. Blazin' Bob doesn't know how to spell shroud, but he is right that a too-slow water pump can reduce cooling capacity. Chrysler engineers did not take a one-size-fits-all approach to engine cooling. The pulley ratio for a car originally equipped with 4.10s is different from the fan ratio for 3.23s, at least it has seemed that way to me.

Look at the fans used. Some had quite a few blades, some had five. I'm thinking that for traffic many blades are better, while at highway speeds they may act as a roadblock to airflow. A shroud makes the fan more efficient, it should be there unless there is a compelling reason for it not to be.

The factory took pains to make sure that the air striking the front of the car actually went through the radiator and not around it. Many cars had rubber seals in the hood region, or around the radiator opening. You may want to check what your car came with and if they're in place.

There are no manifold heat risers on 440Source, Edelbrock, and Trick Flow heads. I would doubt that the higher performance heads have them either.
Your car should not smell like gasoline when idling or sitting. I do not believe 6-pack tuning is for the novice, although the Manifesto is pretty complete. I'm sure the experts here will amplify my statement.

Retarded timing can cause overheating.

RB engines are physically large and can stifle airflow through the engine compartment.

But first you have to measure the situation and see if it is a real problem.

Good Luck! And don't let the Religion Police get you!

R.

Sorry, I'll put myself in timeout

Ever wonder how much heat a set of 3" headers generate ?

What I noticed most ( on the last street car I had with headers) was how quickly it cooled down after shutting off, vs the stock exhaust manifolds..

more than likely that 4 flu radiator is not letting enough air pass thru at idol and low speeds . more rows need more air ... air passing over the first row is heated , then the second heats it more then the 3rd row and it is easy to get very little cooling from the last rows . 2 rows with wider tubes would prob. be better . you say its running warmer , which makes me think it is not really overheating but rather , its not very effective at a low speed due to low air flow or water flow or both. thus the temp creeps up some.... the raw fuel smell is usually poor carb set up or base timing to low. 18 degrees initial timing is close . the 6 pack set up thread is a very good bench mark to use.

What thermostat are you running. 190 degree recommended for six pack. 190 on my 70 Challenger, gauge is way toward hot side. I look at this as normal.

Rich usually runs cool(er). Don't think that is your issue.

Hot at slow speed and cool running at higher speed usually means inadequate air flow. Fan + shroud (hopefully shroud!) not enough.

Can you share some detail on your current fan/shroud setup?

PS: some heating at a stop or low speed is expected. 210 F I think is fine, 220 F some concern and 230F getting too hot for my taste. An after market mechanical temp gauge may help figure it out.

A stock 440/6 installation (this one isn't stock)uses the non-AC water pump with corresponding pulley. So verifying what you have has merit

here we go

440/6 ? ! Did someone say 440/6 ????? That alone will start the ..You'd think the same ones would be sore from trying to pile on to each other every thread but it never ends...

Thanks for all the comments and inputs. It will be sometime befre \i return home but like most car owners you have time to think on issues and have a plan in place to correct those issues, hence my reaching out for advice. To answer a few questions:
**I've read through the 6 Pack tuning manifesto.....may review it again.
**I'm running edlebrock performer aluminum heads.
**I've never used a temp gun, good thought.
**I have a 4/5 blade clutch fan in place with fan shroud. Would a 5 blade fixed fan be better?
**As for "running warmer than I like", it just seems my temp gauge needle is to far to the "hot" side of the gauge when driving slow or stop/starting in traffic (and then again, maybe nothing is wrong and this is where the engine operates according to the set up).
**I have a new 4 row radiator installed and understand the efficiency of the air flow thru the radiator.
**I never gave any thought to wiring the choke fully open and the effect on the engine running rich.

All great points to consider, my car and I thank everyone for the help, please feel free to add comments as every comment helps.