Wouldn't putting in a larger rod reduce the effective area fuel can flow? Am I reading your post wrong? Highlighted in red above. Do you have .075 or .073 rods in it now?

Have you opened the carb and verified the jets/rods? I know you opened it, just wondering if the rods/jets are actually what it came with.

I would try the next smaller rods and go from there. Even though it shows 6% boost, you may not use 6% more fuel, it just has the capability to do it.

I would rather run a little rich than lean.

Way back, well 28 years ago or so, I had a Carter Thermoquad on my 72 Dart. I had the Carter Strip Kit and it had many different styles of rods, 12 sets I think. Some of the rods would have the same diameter top and bottom, but a different slope, some fatter towards the tip and others fatter near the top of the taper.

Measurements of a rod with a dynamic profile on the taper are not easy.

Vacuum controlled jetting area makes for infinite adjustability. Getting the infinite part matched up to what the motor wants is the interesting part. But in reality, so long as the jetting is close, changes in the vacuum of the engine will adjust the fuel trim close to what it wants as the rods move in/out of the jets. You can see a similar relation when you adjust the idle screws and watch a vacuum gage.

I wish I still had that Thermoquad. I had that Dart getting 18mpg with a 360, 727 trans and 3.23 gears with consistent 13.5 second quarter mile times. Car was my high school and after project. Bought the Dart for $50.....and it ate all my time/money for years.

 

Stang - You are correct, my mistake. The stock rod is .075" and the first increment is a .073". I just had it backward. My carb does have all stock jetting, inc the springs.

Yes, the Carter Strip Kit has some unusual rods, inc some with three steps. The kit is my nephew's and he said he put a micro switch above the rods and couldn't get it to use the middle stage - it was either full down or full up. But someplace I read that those rods were meant for RV's, which can stay in a vacuum range a lot longer due to their power/weight ratio. So, I'll probably stay with the two-stage rod - especially since the ones in the Carter kit are way rich given my jetting, and the Edelbrock kit has the rod I'm looking for.

That Dart should have been quick with a 360. I remember on Sunday after church when some of us were headed home. Me in my 383 Bee, a buddy in his 440 Charger, and his brother in a 340 Duster (Twister, I think) - all three within a year of new. Downtown Wichita, so it was light to light. That Duster would almost stay with me!

But, you didn't say if you would do the rod, the plugs, or both as the first step.

 

Gary, the Thermoquad has a vacuum/mechanical enrichment system like the old WCFB and and many of the older 2bbls. The YF does the same. As a result the metering rods are tapered rather than steps. The Chrysler AFBs and AVSs had a two stage metering system with an extra spring around the top of the piston and used a longer main spring and a raised cover along with special primary jets to allow the whole thing to fit in the same bowl.

As for all your Chrysler playmates, all three would have looked good in my rear view mirror. All I had was a .030 over 289. It was, however, a nice 375hp item, two 465cfm Holleys, and redlined at 7500rpm.

 

That would explain the odd rods. As for seeing the Mopars in the rear view, apparently your 289 was Mustang or Comet as they were light. Yes, the B-bodies were heavy, but the A-bodies weren't too bad, but they were still bigger and heavier than a Mustang. So 375 HP would have made a Mustang move. Two 4bbls must have looked good under the hood.

 

375 horses would make your truck move pretty good too, and the two fours would look pretty good as well.

 

I'm not the carb guru that Bill is, so maintaining two 4 barrel carbs would be a bit more than I want to do. As for 375 HP, if I could have it at half that RPM that would work.

 

Yeah, it was definitely a high rpm engine. The car was even lighter than the standard Mustang as it was a '66 GT350, 3.89 Detroit Locker in the 9" rear. It cornered and stopped pretty good too, manual 3.5 turn lock to lock steering, manual disc front 10 X 2 1/2 rear drum with Lakewood Velvetouch metallic linings. It cried for a 5th gear, but needed a chin spoiler since it started to get light in the front around 137mph. With a chin spoiler and a 5 speed, I don't know how fast it would have gone, it had no problem with power, when the front got light, it was still accelerating. Wish I still had it.

Other interesting fact, it got better gas mileage at 75-80 than at 55. You need the old 430 Lincoln engine I had, 375hp at 4800, 495 ft-lbs at 3100, would make a great truck engine, except it is an FE bellhousing and mount pattern and weighs around 800lbs.

 

Ok, apparently my question (Question: Would it be best to re-jet first and see if the plugs are ok, re-jet and go with cooler plugs at the same time, or go with cooler plugs first and re-jet if needed?) was either too complex or the answer was too obvious. I say that because no one attempted to answer it even though at least three of you are reading the mail.

So, here's the plan, Stan:

1. Install the cooler plugs. The reason for that is to see how they do with the current jetting. And, if they look white like the current plugs do and have the overheating indicators then I'll go to Step 2. But, if for some reason they have no signs of overheating then I'll stop, regardless of color.
2. Change the rods to ones with the next size smaller cruise diameter. Assuming that the overheating indicators on the electrodes go away I'll stop.

In other words, I think I'm more concerned with the temps the plugs are running, as indicated by the burned areas and droplets on the electrodes, than I am with the A/F ratio. However, I realize that there are several factors that effect temps, including ignition timing, spark plug heat range, cooling system temp, and A/F ratio. So, if I can get the plugs to quit running hot by using a colder plug and not change the A/F ratio that looks to be the best approach. But, if you don't agree please let me know!

Gee - 137! The Bee topped out a bit above 125, but didn't feel light at that point. Maybe it would have at 137 though. Sure am glad my son isn't reading this.

But, I don't want a 430, especially an FE 430. I'd consider a 460 if it weren't for the gas mileage, or lack thereof. I think the 351M is going to do what I need - a good mix of efficiency and towing ability.

 

Gary, I was getting ready to leave to come over to the Eastern Shore. I would try the colder plugs, if they burn clean and not dark I would leave everything else alone. If they burn a little dark you could try one step leaner cruise, but do keep track of the mileage, too lean will actually use more gas. You might just have to play with it a bit.

The Bee weighs probably 3800 lbs or more, the Shelby weighed 2800 lbs.

 

Crossing the loooong bridge?

Ok, sounds like a plan. Wish I'd thought of it. Tnx. Have a good weekend.

 

Already did, and drove Darth Vader (Matt's group of friends name for the dually) to bring a bunch of stuff over to a storage place here. I can rent a 10 X 15 for less than I was paying for a 6.67 X 12 in Newport News.

I watched that bridge tunnel being built in the 60s. Quick calculation on mine, with a questionable O2 sensor, running it doing the diagnostics and too recharge the AC, it got a little over 10 which is what it used to get before all the reformulated gas etc. I am hoping I can get 12, which would be a 20% increase.

 

Drove that bridge/tunnel a few times to/from DE when we live just out of Wilmington. Quite an interesting drive, at least the first couple of times.

Yes, I'm quite well aware of how good it feels to get a 20% increase in MPG. Rusty was doing about 10 MPG when I got him and going through the Holley carb got him to 12.25 on the highway. Changing to the Edelbrock jumped it to 14.25, and changing tires got it to 14.6 MPG. To be fair I'll just use the 14.6 and 12.25 MPG figures as the 10 MPG with with a carb with problems. So, that's a 19% increase, with the carb swap accounting for the vast majority of it.

Or, to put it another way:

• I can take Dad's truck when I go up to see him and get 10.5 MPG
• Or, I can take Rusty and get 14.6 MPG, which is a 39% increase in gas mileage, a big increase in fun factor, but a large reduction in creature comforts as the wind noise is awful since the window runs are non-existent, the back glass is jammed shut to prevent anyone from coming in since its lock is broken, and the radio couldn't be heard if it worked.
• Another approach is to take the Murano, which I did yesterday/today, and get 23 MPG. That's a 58% increase over Rusty and a huge improvement in creature-comforts: The A/C works, there's almost no road noise, no wind noise, and the stereo has over 800 songs stored on the hard drive.

 

My AC in my truck works great, as a matter of fact, changing it to the 94 up system was a huge improvement. Before, even with everything perfect, if I shut it down on a hot day it would take 15-20 mins of driving before the air from the vents got cold. Now with the insulation, larger evaporator, FS10 compressor and multi-pass condensor, it's cold pretty fast.

You make like Nissan, but ever since Renault got involved with them I want nothing to do with their stuff. I'll just have to get my 95 Continental on the road.

 

You know how I feel about making the changes. You need some type of control to base your findings on. So IMO I would just make changes one step at a time so you can actually see what the change has done.

 

Yep, I feel the same way. Will go with the plugs as Step 1 and report back.

Bruno - do you have the 1405 yet? The new-to-you one?