Dual Carbs

[glasspacks]

Any body running George Ashe dual carbs? I am interested in the performance or advantage of them or how it affects the gas mileage. I would suppose you would need to open the exhaust also.They look cool!! Thanks Robin

Hi Bob here from Vancouver Island, when I saw this post it brought back memories.  I drive a 1941 Fargo, 230  engine is out of a 1954 Dodge.  I fitted three SU carbs on home made manifolds, engine response was amazing, gas milage not so much.

Engine had long tube headers and dual glass pack mufflers.  Biggest problem is keeping them in sync and not freezing up in cool weather.  I switched it all back to stock but now considering a new dual barrel carb with pre heat.

Tuning of the tripple carbs required a vaccum gauge and a glass spark plug, .... yes they made them for tuning motorcycles in England.

Amazing flame colour inside a cyclinder, adjusted the mixtures for best performance,   Great memories but more trouble then it was worth.

 

Cheers,

Bob.

[55 Fargo]

Hi Bob here from Vancouver Island, when I saw this post it brought back memories.  I drive a 1941 Fargo, 230  engine is out of a 1954 Dodge.  I fitted three SU carbs on home made manifolds, engine response was amazing, gas milage not so much.

Engine had long tube headers and dual glass pack mufflers.  Biggest problem is keeping them in sync and not freezing up in cool weather.  I switched it all back to stock but now considering a new dual barrel carb with pre heat.

Tuning of the tripple carbs required a vaccum gauge and a glass spark plug, .... yes they made them for tuning motorcycles in England.

Amazing flame colour inside a cyclinder, adjusted the mixtures for best performance,   Great memories but more trouble then it was worth.

 

Cheers,

Bob.

Hi Bob, so with your added carbs, and headers, that Fargo have a quite a bit more kick did she? I am tossing the idea of splitting the exhaust and going with a 2 bbl carb, or staying completely stock, I have a 251 engine. The 230 you mention, was that a Canadian Dodge, then it may have been a 228 long block....thanx for the post

[Don Coatney]

it is? what's the frosty-looking substance on the exterior of mine?

i believe you are correct about the relative humidity, ie, more likely to ice-up with high r-h. and it occurs when the ambient temp is above freezing, too (i know you know that).

The frost on the outside of a carburetor does not affect how the engine runs. The frost on the inside is what matters.

[Jim Shepard]

I'm running dual 1bbl's on my truck and they have been working working great. I got the George Asche setup with manifold supplied by him as well. Linkage is very easy - just hook it up to the stock bell crank on the manifold. I'll try to post some pics this weekend.

Pics?

[John-T-53]

Here's some pics. From one year ago - just before dropping it into the truck! 

 

I got the manifold, carbs, and linkage from George. No cam, though....still running the stock one. The manifold had two uprights brazed onto the cast iron, and was a little rough inside, so I took it a step further and smoothed out the passages for better flow. Took moderate effort to fine tune the linkage to work right, but haven't had to mess with it since.

 

George set these carbs up with '41 tops so I could keep the hand choke. Air cleaners from Tom Langdon top 'em off. He had to get me modified air cleaner bases to work with the straight style air horns on the carbs.

 

Takes longer to warm up, and more choke is necessary, but it runs well and gets slightly better mileage. Power is a lot better but this is also due to making the motor a 230 where as before it was a 218. Most noticeable was a huge increase in low-end ability.

[Jim Roach]

John,

 

How did you get the outside brazing so smooth?

[Jim Shepard]

Cool setup, John.  I still don't know anyone who's used the Offy or other after-market dual setup on one of our trucks.  George's setup using the truck manifold allows for the stock linkage to be retained.  Part of my mods will be to fab a similar bracket between the carb and manifold and spin the carb around to get the linkage on the passenger side so it lines up with the linkage under the floorboard.

[John-T-53]

Thanks Jim...yeah the original linkage can't be beat! I heard offenhauser castings are prone to quality issues, also their design for our motors puts the carbs so low the flow ain't that great. I like the Edmunds manifolds, however they are rare and expensive. They also have an heat pipe supplied by the engine coolant.

The exterior brazing on the manifold George sold me is untouched. That's how it came and he did a great job. I just deburred the inside.

[Jim Shepard]

What did George charge for all this?

[John-T-53]

I think it all was around $500 including exchanging my old single carb and manifold.

[Semmerling]

 

 

For what it is worth, I'll offer up the following observations on this 10 year old thread as it is the kind of question that is timeless.

 

4 generations of working on the same 1934 Dodge DR convertible means that I have rebuilt the engine 2 of the 3 times it was done. Everything was stock for all three times. And then I asked the very same question right here on this forum a year or two ago and went to work. Here is what I have come to realize. 

1. Freely up the exhaust flow is by far the single greatest improvement that can be made that is reasonably inexpensive and if you do it, get the highest flowing exhaust system you can. No "pinches" in the pipe casting, try to use direct in-line run right out of the head and before any bends or redirects. Nothing that is so poorly designed it impacts the mechanical fuel pump (which can easily run 3 disciplind carbs. Recognize right off from the start that when you take off the stock exhaust you are essentially opening up the intake manifold's bottom and that will require impactful decisions to the intake as a whole as well. Be realistic in your expectations of what these engines can actually deliver in regard to modern performance standards. Past the exhaust, there are very few and relatively limited and expensive alterations that will have to be done with every increase in horsepower and measureable performance improvements coming at a very high $$$ to speed ratio.

2. A single well tuned carb can deliver all the gas you would need to run your engine in all but a heavily modified engine.  

3. If you aren't willing to improve the cam, then you are never going to get the potential out of these block. The only reason to do the cam work is to commit your self to doing everything else as Plymouth Adams properly addresses earlier in this thread as well as fuel and lightening. 

4. Dual are nice to look at. Triples are nice to look at. Only one has the potential for any kind of efficiency improvements and, unless you are driving 300 miles, you won't notice it at all and the expense to get the savings would buy your more fuel than you probably will spend in 2 years of real driving.  Which one? Triples. Pick the one you like the looks of as efficieny is marginal if at all. 

5. Do not confuse Carter B&Bs with Chrysler B&Bs, most do. The later is a wholly unique in design and can only be set up for efficiency with access to a dyno and then some of the best minds on topic say its marginal. The later also suffers from an idle state design flaw that is impactful, resolvable and wholly unique in ALL of carburation world. Chrysler B&Bs would be your best choice ONLY if you want to run twins that actually were once originally offered.  Reread #4.

6.  As Don mentioned earlier, The exhaust makes a difference and the presentation can be greatly improved. In fact, if you do a really excellent job squaring everything away, standing still your can will be clearly capable 0-60 in a manner directly correlated to the IQ of the person listening to you, which in many instances with be under 4 seconds on pump gas going up hill. 

So...why would does one do it. For me it was an improvement in acceleration going up hills. Static state, open hood performance saw a remarkable increase of close to 200%  Was the project worth it? Absolutely. All that and this....

 

 

Edited July 19 by Semmerling

[greg g]

There are a couple other changes that can improve performance.  Milling the head to increase compression ratio.  You want to be in the 8.5 to 9.5 to one area this improves throttle response and horsepower, while still running 87 octane.  Grinding the intake and exhaust ports to match the gaskets, and lightening  the flywheel. Completes mods that are inexpensive and have a big seat of the pants dyno feel.  I believe I had my head done for less than 50 bucks but that was in 2007 or so.  I did the port grinding here.  No need to look for a mirrored finish.  Roughness adds to intake swirl which creates more well mixed air fuel charge.  My machinest told me that some exhaust back pressure is a positive thing so free flow mufflers and a couple bends are bennificial.  The result is an engine that will pull most area hills in Overdrive even with a full fuel tank and trunk packed with travel stuff.

 

One item for more consideration  is gas line material.  Looks like yours are copper.  Copper has a tendency to get brittle when exposed to vibration, this can cause splits to develop .  That new nickel steel brake line is easy to work and resistant to work hardening. 

 

[lostviking]

Yes, copper is for show cars, not road cars. It's a big no-no for brakes or fuel.

[rockingjd]

My engine on the run stand before it was installed in my '49 Fargo. 265, shaved about 1/8" off the head, reground cam and slant 6 distributor swap. A good friend did the welding and I made up the linkage. Sounds nice and drives nice. Extra horsepower? Yes. How much? don't know.

[Semmerling]

On 7/21/2024 at 12:15 PM, lostviking said:

Yes, copper is for show cars, not road cars. It's a big no-no for brakes or fuel.

 

Yes, for both gas and brake lines as seen in road cars that are sometimes show cars. 

The big "big no no" is confusing the nickel copper fuel lines with pure copper lines.

They are extremely strong and durable, resists corrosion and wear and, as importantly, resistant to heat.

Volvo, Audi, BMW, Aston Martin, Porsche, etc. etc. etc. etc.

Been about 20 years now......try them, all the benefits of steel and a whole lot more. 

 

George Asche Dual Carbs is a very well designed and made set-up. Takes more than a spoonful to set it up properly but is well worth the work. See the other write ups on this site.  For both go and show....

 

 

Edited August 9 by Semmerling