as to temperature;
I run my lil 367 at 205 to 207,by IR gun, all the time, and on purpose. The hi-flo stat is rated at 195, and the clutch-fan keeps her right at 205/207.. And she went 93 in the Eighth at that, with a lil 230*cam. It don't matter what the ambient is or how hard the engine is working, in-traffic or not,... 205 to 207.
But, I run fresh cold air into the 750DP, and she sits on an AirGap.
As to what circuit is working;
I currently have my 11/1 367 set up to run at 65= 2240 rpm in overdrive. She pumps pressure at about 180 +/- a couple.. The Barracuda is naturally a bit aerodynamic, and at 65 the carb is barely open....... partly because I am also throwing crazy timing at her, commensurate with what she wants. Some days the alloy heads want over 60* timing. Or perhaps I should say, she tolerates over 60*. I set that with my dash-mounted, dial-back, timing-retard box, advancing in 3* steps,, and then closing the throttle back to 65mph, and so on, until each step no longer increases the MPH. Then I stop the car, and change the slow-speed fueling to see what happens. Eventually it got too lean and I had add some back in.
If I told you that my car, on a certain day-trip, averaged 32mpgs, would you believe me? Well that was not with the same 65=2240 gears lol. That was with gearing of 65~1600 and a 223@.050 cam,lol.
Because you have twin 660s, I'll bet your primaries are barely open.
To see where mine were, I fabricated a simple carb stop; see below if interested.
BTW
lean is way easier to determine than rich, so start rich and work backwards. If you lean it out and nothing much happens, lean it out some more, until something does, lol.
Read the signs; If a cold engine starts and runs without choke, she is rich. If the engine runs worse as it warms up, she is probably rich. A multi-strike can hide this.
For best results, the cruise timing will have to get into the deep 50s at typical rpms in the 2200 to 2700rpm range. My rule of thumb for ballparking is to double the rpm and divide by 100, so cruising at 2200 will need 44*. Cruising at 2700 will require 54*... to start.
The purpose of timing at this time is to start the fire early enough to put peak cylinder pressure in the neighborhood of 25 to 28 degrees AFTER TDC. This is where it will apply the maximum amount of push, available in the expanding gasses, to the rotation of the crank.
Keep in mind that of all the energy contained in gasoline, only about 1/3 gets into turning the crank, with 1/3 going into the coolant and the other into the exhaust. You can't do much about the exhaust. But you can about the cooling system. If you run your engine too cold, the energy will want to go into the cooling system, instead of, into the crank. In my experience, 205* is working very well for me.
Get you coolant temp settled before getting too deep into the carb, else you may have to tune it twice,lol.
Don't forget the role elevation plays in air-density
Happy HotRodding
My throttle-stop;
I made mine from a J-shaped length of coat hanger, with one leg about a foot long and the other about 4inches; took about one minute. It took longer to find a new softer return spring, and the tiny wire-clamp (stopper) that makes it all work.
The way I made it work, is like this;
I drilled a hole in my front-mounted return-spring anchor,big enough to receive the wire, and twisted the thing to 90* from the return spring. Then I slid my wire clamp on the long leg, draped the J over the K-down pivot, while sliding the long leg thru the just-drilled hole. I installed a softer return-spring on the carb. Ok now, I put a lil distance between the loop and the KD pivot, about 5/16 inch, and tightened the cable clamp against the spring-anchor that was bolted to the intake up by the stat-house, to be a nice repeatable stop. Finally I reinstalled the stiff return spring but now onto the J-wire. To do that, I had to bend a lil hook on the short leg. Ok now I was all set, with an easy pull to the stopper, on the J-wire; then back to including the stiffer stock spring with about 5/16" travel of the throttle from idle to when it hit the loop in the J-wire; perfect.
I adjusted it to stop the throttle at a tiny opening... but it is a floating deal; so I can override it anytime, and it does not interfere with the closing action. So then I can boot it up to say 65mph and then reduce throttle, then increase throttle to where I can feel the stopper. Then Badaboom, hold it there long enough to establish an mph. If it's not right, then I gotta stop the car and readjust the stopper. It doesn't have to be exact, just close enough; BUT it does have to be repeatable.
Afterwards, I used it for a cruise-control. And it's kindof cool cuz when I hit the hiway, I can just slam the pedal to the stopper, and sooner or later, she will plateau on cruise-control.
I have a manual trans so she is very responsive to tiny inputs. IDK how well it would work with a hi-stall, but it also worked well on my 904 equipped DD, I just had to wait a lil longer for the Rs to settle.
If you want to, you will figure something out.
