Asche Dual Carb Intake – Final solution of the Idle set pressures on dual Chrysler B&Bs

[Semmerling]

This thread is to show all interested members, my final solution to how to properly and efficiently maintain the considerable forces on the dual’s throttle actuator so that, while in idle state, just the right amount of force is applied and is fully user adjustable over time. I designed this because, over relatively short periods of time, the return spring will weaken. This is because return spring pressure is never relieved and always working, fatiguing the spring. This new design allows the user to simply adjust the exact amount of spring force required and keep adjusting it as the spring weakens over time. Moving the spring arm in the linkage is not a solution. It will eventually chew up the main shaft geometrically increasing failure risks. One can now get perfect returns and greatly reduced pedal pressures.

 

Here is the digital representation of the adjustable return spring device ,  I do for these types of projects.

 

 

Notice that one end of the spring will be bent as a hook on whatever your static hold is. The spring’s other long straight end is inserted into the threaded shaft and comes out the other side where it is bent and retained in a slot. This is much better than the single set screw holding the arm itself on to the main linkage shaft. That threaded shaft runs through an unthreaded (smooth bore) body that attaches to the linkage arm. The whole assembly can free rotate on the arm, which is more efficient than a direct spring attachment, easing the pedal pressures as well. One simply adjusts the two nuts to accurately dial in the exact force needed to keep both carbs in idle. When the spring slacks over time, one can quickly tighten it up instead of changing the linkage arm on the main shaft. It works perfectly and resolves the idle pressure problem and attends to the  pedal pressure dilemma. Lastly, with all the adjustment provided you can make a flat facing on the linkage main shaft and set the arm in place forever. We now have  reduced the chances of a catastrophe to close to zero.

The Real Deal.....

 

 

 

 

 

 

 

So why is all of this important?

I had a conversation with one of our members about the choice of carburetors on the Asche Dual Carb system that I have been writing about recently. He is one of the Nation’s most experienced vintage carb gurus, having had over 60 years experience. His questions “why did you choose that carb model?” My answer was “those were the carbs that George sent along with the intake.” To which he said “I thought you would say that and that makes sense as that particular carb type was found on Dodges in a dual configuration. I like  your fabrication work but those carbs are the worst carbs of that period.”

 

The carbs you see are NOT Carter Ball & Ball. This carb model is a Chrysler B&B design produced at a sublet of Carter’s, the Penberthy Carb plant. Carter did sell a very few of these carbs to Studebaker and International Harvester for a small number of their truck offerings. They are a unique, proprietary design that we find nowhere else. Know this, the Chryslers primary use for these carbs ended up being for stationary motors on agricultural equipment and industrial applications. Take that to mean, the engine may blow up but it won't be on public roads with passengers. Only Chrysler designed a carb with positive idle pre-set, every single other carb made for cars in this era avoided this issue. They also only have 4 screws to hold the top casting to the bowl resulting in warpage that can cause fuel leakage at the top gasket. The vacuum piston is brass but sits within a zinc alloy chamber, although not common, it can hang up. Lastly and perhaps most importantly there is a spring that loads the accelerator pump. That spring can provide uneven squirt. That spring is preloaded by the linkage and it is that load that is the heart of the idle set problem.

           
George was correct in using a Chrysler product, and the only one ever offered as duals  for a Dodge. And, as I have stated a number of times, his carb preparation was excellent, it still leaves the user with a significant problem that is perhaps one of the reasons why we see so few disciplined, stable, clean and finished examples of finished duals and triples with these carbs. George’s intake is a well designed and well executed intake with all the features one would want and most “period” intakes simply do not have. It’s all about flow folks, flow. Now let me be clear and fair here. I run these Chrysler B&B duals and they run better than my single carb. But what they will never be is as safe and fuel efficient as the vast majority of other dual carbs choices.

 

Here are the reasons why...    

1. These carbs will never rest in idle state like every other carb manufactured throughout the period without direct intervention to overcome the pre-load problem. The “pre load” constantly wants to roll the actuator into a high RPM mode and it takes dedicated force, delivered to the linkage by way of a return spring system, to avoid that. What this means, and meant at the time, is that a failure of the linkage return spring means rapid acceleration with all the consequences of that. Whether parked....low speed driving...or highway speeds, if the return spring completely fails your motor will race to destruction if you do not immediately recognize the condition and if you don’t  TURN OFF THE MOTOR...5-4-3-2-KaBoooom!        

Now if you are thinking, “run more springs!” well, work it through. It takes the exact amount of force to keep the duals in idle state. Any more than that and it only adds to an already heavy pedal. Anything more than the exact, required weight, wears the throttle linkage, work against your foot, destroys whatever pedal sensitivity you would consider normal and runs a higher risk of pulling the throttle linkage spring arm loose from the main shaft or the other side linkage, or pulling through the Allan key. Multiple springs in this case means multiple weaker springs. Once you drop in strength to the "other" spring, it may be too late. Multiple springs means ZERO chance of adjustment. Don’t do it.

 

One wants to be able to ADJUST the spring tension to the exact point that holds the duals in idle. Remember, if the spring weakens, you will know by the higher idle.....it is the risk is of gross failure of ALL return pressure that will destroy your engine. You want the strongest single spring, and be able to adjust it multiple times to its perfect weight as the spring weaken and stretches over time. Some of you have probably already figured out what attending to collective idle set with “Triples” of this carb would be like at the pedal when properly adjusted. Dragster, sure, one stomp and you are off. Driving? Not so much.

2. This model carb has a wider footprint of flange size #3 (2 15/16.) In my case, my original carb  was an early model carbs flange size #2 (2 11/16 EX-22 ’34 Stromberg). The Chrysler B&Bs are less efficient to the point where dual carbs of this model give you a fraction of the anticipated “gas efficiency” gains that is one of the hallmarks of running duals on earlier intakes. Let me be clear here, if one were to take the earlier, smaller Stromberg and make them duals and set them on George’s intake, they would send the larger, less efficient Chrysler B&B’s home to Momma in tears. It does mean that one would have to use a reducer on George’s intake to run earlier carbs. This is not a considerable issue. It also means that, where as the Chrysler B&Bs have a dual arm on the carb’s throttle actuator, the Stromberg do not. As a result the throttle linkage would work differently with the car’s own pedal actuator pulling up an intermediary linkage connect to both carb’s actuators. This is not a considerable issue either.          

3. The top of these carbs has a very low wall to set an air cleaner on. Compression ring types will come right off. The solution is to run multiple Allen set screws low on the ring. George’s intake has a design attribute that is really excellent. Unlike many other period deigns for the straight 6, George’s comes out of the block and rises up tall creating velocity. Know that that translates to a higher vibration forces as the engine’s vibration at the top of the carb is magnified. Higher walled carbs manage those forces easier. Carbs with center holds are best, but compression side mounting does work reliably.

           
Having said that, I am currently in process of restoring two Stromberg EX-22s. One is a 1934 and the other a 1935 as the ’35 introduces a vacuum tap in the base. Will I go as far as swap them in? One instance of anything close to a run-away-idle set is all that it will take.    

Edited August 22 by Semmerling

[Sniper]

Not really sure I buy any of the claims in this post But if throttle return pressure is so critical to proper idle why are you even using Springs? why not design a counterweight that will hold the proper tension at idle and never ever wear out?

[Semmerling]

I certainly want you to be more confident about what I wrote....so lets see if the following helps. 

 

Potential Claims...lets state that properly. I made the following observations, recommendations for a solutions....since you used "any" well lets do them all. 

1. The Chrysler B&B designed carburetor vs. Carter B&B designed and built carburetor.

 

The following comes from one of it not the most knowledgeable living carburetor  specialists. 50 years and 140,000 carbs have passed through or are in his hands.

 

The the Senior B of B&B died, his son, Jr. B of B&B,  went to work at Chrysler and designed a carburetor that was built by a sub of Carter named Penberthy Carb. It is the ONLY carb to preload the idle that made it on Chrysler products. They are the only carbs with pre-load that were made, period. That carb ends up being used primarily for, as I said on stationary agricultural and industrial equipment. The failings of that carb are what was laid out to me and that which I posted here. Like it or not....all are the facts. 

2. The Idle Pre-set issue that many contend with needs to be fixed and in a way that allows for the lightest pedal, linkage and firewall actuator ('34) possible.  

 

The whole Idle set issue of these carbs is but one of many problems that earn it the reputation of the guy that has made a successful career of fixing carbs. It is one of a handful of carbs that he strongly recommends not be used and tries hard not to even suggest that they be rebuilt. For all the reasons stated...those are the facts. I have spoken to a good number of people that have real difficulty with the pre-set issue, some on this board. When doubling or tripling these carbs, the pressures  double or triple and the result is very noticeable. No surprises here....all of that are well known facts about these carbs.

3. Single Spring or multi springs, use single spring.

The proper way to resolve this issue is to toss these carbs and go with any other good well designed carb of the period that isn't THESE carbs. But, I went as far as to make these carbs work with all the caveats, conditions, risks  and requirements as laid out. I showed how a single quality spring can be used. How it can be tuned for the idle state and, in doing so, keep the lightest possible pedal, linkage and pressure on the on-board actuator. Now lets say that I want to SOLVE this issue with these carbs as an engineer. I would remove the accelerator shaft enlarge it and use torsions springs externally. So, that was done. The force was SO GREAT that the torsion spring was set aside as requiring (no surprise here) attributes to be incorporated into the base casting. Counter weight? Whereas a torsion spring used in a lateral transfer will wear uniformly, a counter weight does not. It is subject to it's mass being shifted by aberrant movement on the linkage...bump perhaps, does not insure constant force, would be complicated to make adjustable and would require nothing as simple as I showed here. 
 

4. The spring weakens over time.

As you well know, any spring kept under tension weakens over time. That weakening can be static state can de reasonable calculated and is accelerated and less calculable by heat (present), vibration (present), work flex (present), etc. In EVERY OTHER carbs application of the period, the carb is at rest at idle and does not have this problem. 

5. The Efficiency of the Chrysler B&Bs

 

I have listened to a number of people explain in certain terms and that I myself have stated a number of times, that I believe my car has never run better in regard to starting, acceleration, especially under load on hills on in a higher than optimal gear. I have also head enough stories that one of the potential benefits of duals is better gas economy. Those stories are regularly told and I always ask the carbs used and the distances traveled.  Never, not once was the story relayed to me more powerfully that by the carb expert, who simply made these statements. The people that specifically wanted efficiency and had the means to properly judge it by maintaining reasonably uniform speeds over long distances all found a potential maximum savings of 15%-20% and firstly, non of them used these carbs by design and secondly, these carbs do not have the build attributes either by internal dimensions or mechanical attributes (jet, venturi, float design, accelerator pump, etc.) either by design or adjustment to make the list. According to those I spoke to who would know, the Chrysler B&Bs run rich. I don't see this as a problem as the money spent on the duals would buy more gas than consumed for a long time. The last thing that I expect is for this block, these carbs, this drive train, weight to be efficient. 

6. Low walls on the Chrysler B&Bs

Look at them.

Sniper, I for one look forward to you finishing your 6 project and reading about what you have learned that worked and what you had to over come and how you did it.  I have only been working on this car the 30 years as a hobby, but I try to give back as much as I can. My real passion was supercharging Dodge's V10s 25 years ago. So its been really 5 years of dealing with improving the performance of cars with less torque than the wheel nuts of the V10s.  Hope this helped, thanks for taking the time to express your concerns. I would say lastly, that a number of people I spoke to have stopped writing here at P-d because of the idea that it is a hostile place is legion. They still come on to read, but they will not write and some of them have actually finished their projects and they run really well and have a great deal to offer up.  I'm not saying that your entry by itself was lacking in clarity of what claims you found to question, nothing like that at all....

 

 

Edited August 22 by Semmerling

[Plymouthy Adams]

😴

[Sniper]

Dude, whatever.

 

All you have to do is hang the proper weight on that bell crank you have circled in red and you will ALWAYS have the proper return pressure with no concerns about spring wear or adjustment.  But overly complicated isn't my thing.

 

 

 

 

 

Edited August 22 by Sniper

[Semmerling]

 

Not a solution....not if you want it to work properly. Won't be doing that for all the reasons I've already spelled out for you.  When you do your Asche Duals you can tell us all how you resolved issues. The difference between you and me is that I actually finished my project and worked through the various issues with some truly helpful people who stepped forward and were actually quite illuminating on what they had for both open and closed issues. 

 

You finish you project and then you can tell us all about what you did to make it all come together and post here so that posterity can actually learn what you did and why. You can take the time to post the pics and write it all up. Until then, Sniper, you are just that guy that takes 2 seconds to type  some vague snide snippet comment. Nothing I've shown here is complicated....you have no idea what complicated looks like in engines.  You just hate people who actually finishing something and then take the time to help others understand how they went about it. Sniper....perfect name. 

[47 1.5 ton]

 Reading through this post points out several issues that need addressed when using the Chrysler B&B’s during initial setup. I also wanted to point out that once running, there needs to be slightly more spring tension applied and this adjustment would be a nice correction.  My application is slightly different (using the completely factory set-up from air cleaners through intake manifold) but the carb issues were the same as I encountered. 
  First time I ran my truck down a fairly steep hill at ~12k I noticed my throttle wanted to stick open with the duals because I had only figured spring tension at idle running. Although a light car may not see the extreme conditions, I believe it’s still something to keep in consideration. I did not have that issue when the single was installed. My correction was to add (2) more springs for safety which adds too much load to the linkage. Although adding counter weights to the system may be good in theory and possibly be tested, I believe the measurement needed could be in pounds instead of ounces.

  Thank you for adding this adjustment option to the forum.

 

  Kevin

[FarmerJon]

I have played with the WA-1 carb and the B&B, single carb.

Performance was improved in most RPM ranges, BUT am back to a B&B because i couldnt get the off idle to WOT bog out of the WA-1. It may need a larger accelerator pump jet, but not really a common thing to find. I see that as the biggest downside of ALL of the Carter 1 barrels: tuning parts availability. Maybe I am spoiled by Holley 4 barrels, but I would LOVE a carb with a common availability of the tuning parts.

Yes, I know, there are NOS Carter parts to be found, and a reasonable amount of new part support, but it still is a lot of trouble to find.

Edited August 23 by FarmerJon

[lostviking]

Wow! After a hundred years or so, a solution to a problem the manufacturers never saw, and one I've never experienced.

[Plymouthy Adams]

I one day expect to have to change the spark plugs in my 1940's Maytag washing machine engine.....never saw that coming.....I will however say we each see things in a different light and not all approach the subject in the same manner.....sticking to what works for you is best and though not your approach, while different, not necessarily wrong either.  Getting the results you want and need and keeping it safe to operate is job one, not so much the dancing in the streets you see with every freaking commercial on TV as they say; gag me with a spoon.   Lemmings are commonly found in a zoo in the US, not so much on a forum...but, they can be found in small numbers there at times.  

[Sniper]

10 hours ago, Semmerling said:

 

Not a solution....not if you want it to work properly. Won't be doing that for all the reasons I've already spelled out for you.  When you do your Asche Duals you can tell us all how you resolved issues. The difference between you and me is that I actually finished my project and worked through the various issues with some truly helpful people who stepped forward and were actually quite illuminating on what they had for both open and closed issues. 

 

You finish you project and then you can tell us all about what you did to make it all come together and post here so that posterity can actually learn what you did and why. You can take the time to post the pics and write it all up. Until then, Sniper, you are just that guy that takes 2 seconds to type  some vague snide snippet comment. Nothing I've shown here is complicated....you have no idea what complicated looks like in engines.  You just hate people who actually finishing something and then take the time to help others understand how they went about it. Sniper....perfect name. 

 

Really dude?  Crude attacks?  Coming from you, yes.  From me just pointing out stuff.

 

I don't quote mystery experts as backup to my claims.  In fact, when I do cite someone else I CITE them, I give the links, I show the data, I name the names. When I see a claim of mystery expert information, I know it for what it is, BS.

 

Finally, mr know it all.  I do not have, nor have I ever had a set of Asche duals.  So I can't complete a project I never started.  But if I did have as set of Asche Duals that were setup by a recognized expert (no mystery expert here) on these engines I sure as heck wouldn't be bad mouthing the carbs he setup for me unless I had a legit, documented issue and I would have reached out to him first for a resolution.

 

But you do you and I'll do me. 

 

 

 

 

[lostviking]

One thing I'd suggest to anyone who needs to write a book on this forum and use overly complex wording to sound knowledgeable, please proof read your posts. It takes all the wind out when you don't.