Stromberg Chrome Linkages

Good news for all our chrome Stromberg 97 customers. The full TwoStep linkage range is now available with chromed die-cast levers and polished stainless steel. Designed specifically for use with multiple Stromberg 97 carburetors, the TwoStep range of direct and progressive kits covers all of the commonly available 2×2 and 3×2 intake manifolds – principally for flathead Ford, small block Chevy and Ford, plus various other vintage OHV V8 engines. Chrome linkages for 4×2 and 6×2 applications are also available to order.

The new chrome range perfectly complements our popular chrome Stromberg 97 carburetor (9510A-CHR), and chrome fuel delivery parts. With our show chrome models now accounting for a significant percentage of carburetor sales, customers were naturally asking about matching linkages. So we’re particularly pleased that we can offer real show quality chrome and polished stainless pieces….and at very competitive prices.

Designed and manufactured exclusively by us here at Stromberg Carburetor, the TwoStep linkage range combines clean, traditional looks with maximum leverage and huge versatility. All kits come pre-assembled and install in just two simple steps, without the need for extended throttle shafts. Here are just a few of the features and benefits:

Direct linkages available with swivels or rod ends – opposite threaded for easy adjustment.

Versatile progressive linkages allow you to choose when the secondary carburetors open.

Every kit includes two Stromberg ‘Snapback’TM throttle return springs. Wrapped around the linkage end of the throttle shaft, these chemically blacked, stainless steel torsion springs snap the carburetors shut, yet virtually disappear from view.

Every Stromberg TwoStep linkage kit comes with full instructions, and further help with selection, installation and tuning is available at the Stromberg Tech Center at www.stromberg-97.com.

You’ll find all of our linkages, regular and chrome, on the Stromberg website. Click the link to check them out.

Chrome 97 crown for 111 Digger

We’re going to let the pictures speak for themselves here, as once you’ve seen this set-up, there’s not much else to add. Before our trip to the Lone Star Roundup earlier in the year we emailed a lot with Steve Wertheimer who, along with a bunch of cool cars, cool bikes, cool house, cool garage, cool music clubs – you get the picture – also happens to head up the Roundup. Steve mentioned his new digger and the miserable old 94s he had on that awesome Norm Jones-built Desoto Firedome Hemi and to cut a long story short, fedex delivered six new chrome 97 carbs, plus a new chrome Stromberg 6×2 direct linkage, just before the event. Steve had top local polisher Wade ‘Buffy’ Monson (512 903-1996) polish the whole damn intake manifold and we installed the carburetors when we got out there.

Keith Tardel (at Rex Rods), who built the car around one of his Chassis Research inspired frames, revised the linkage to drive the new 97s, and ‘El Jefe’ pretty much debuted the car at the HAMB drags – where most of these pics were taken.

We’ve been hammering on about our chrome 97s and our cool 6×2 linkages now for most of the year. So I guess this is where it all comes together – a full chrome 6×2 system with all new chrome Stromberg linkage. On one of the coolest nostalgia diggers around. Does it get any better? Not from where I’m sitting…We’re honored.

Thanks to all our photographers, Buzz M Jones, Nick Savo, Jason Veale, Blake Burwell, Trent Sherrill and Rick P here at Stromberg HQ.

Tuning the Stromberg 6×2 linkage

You’ve chosen your Stromberg 6×2 kit. Now let’s get it working…

It’s not hard to see why every hot rodder loves a Stromberg 6×2 system. It’s an eyeful from every angle. And it hauls ass too. But don’t forget that 6×2 systems were generally designed for racing, so making them work effectively on the street is another question altogether. Now, we’re not going to be talking about which Stromberg 6×2 kit to select for your intake here. We cover that in another Tech Center How-to (and elsewhere on this Bulletin). What we’re talking about is how a 6×2 intake can be set up, with a linkage that helps your whole application work better…

First off, we better remind everyone that a 6×2 system is no place for worn out old 97s. You need good reliable carburetors with good fuel metering, no play in the shafts and no air or fuel leaks. Six air leakers is a problem for good idle. Six fuel leakers is a problem for your personal safety.

Racing. If you’re genuinely using six 97s to go racing then it’s simple. Buy a Stromberg 6×2 direct linkage. And set the pedal link to open all six at the same time – quickly.

On the street. OK, so what about the 6×2 linkage in your grocery-getter? The truth is, we can’t give you a definitive answer for every application. But we can say that, whatever you do, you’re probably going to look at a linkage based around two Stromberg TwoStep 3×2 progressive linkages, plus a Back-bar kit to join the two banks of carburetors together. Linkage installation instructions can be downloaded at our Tech Center, of course.

Let’s look at some basic principles and remind you that all Stromberg progressive linkages are hugely flexible in operation, so you can tune it for many different outcomes. One setting does not fit all applications, and the weight of the car, gearing and rearend ratios, engine tune and drivability, your favored freeway cruising speed, and more, can all play a part.

Pedal response. As a rule, you want smooth throttle operation with a slow pedal ratio, ie. you push the pedal further for a set response at the carburetors. Do the opposite and the throttle becomes like an on/off switch, which is no fun on the street. Now, your pedal ratio and travel are probably fixed, so being able to change things at the linkage end is important. There are three adjustment holes at the top of the long back bar levers. And if you link your pedal to the highest hole and set the link to the carbs in the lowest hole, you will get the slower throttle response. The opposite is true of course, if you find you are bottoming out your pedal before you hit WOT and you need faster response at the carburetor end of the linkage. Remember, of course, that you must never hit Wide Open Throttle (WOT) with any pedal travel left to go, as forcing the pedal further could damage the linkage, stress all the links and, worse, break it and leave your motor uncontrolled.

Four carbs working. Here’s the next thing to think about. Just because you have six 97s on the manifold, it doesn’t mean you have to use them all. One option is to use our 29447K Blank-off plate kit under the center carbs on each bank (remembering to use a gasket above and below the plate) and blank off the fuel to them too, keeping the outer four operational. So it looks like a 6×2, but operates like a 4×2. You’d keep one carb pretty much over each set of intake ports. Plus you’d be looking at 4x162cfm = 648cfm – enough to run a 350 Chevy and rev any older motor well beyond its comfort zone.  You could run a Stromberg 6×2 direct linkage opening the four outers together, or you could hedge your bets and go for the progressive option in case you ever change your mind on the center carburetors. The 3×2 progressive on each bank can be set up so it pulls the outer carbs from idle.

Six carbs working. Ok, so you want the full 6×2 street experience? Let’s talk about linkage adjustment. With the progressive sliding links on the top adjustment holes in the center carburetor levers, and the sliding stops adjusted so that all three carbs on each bank reach Wide Open Throttle (WOT) at the same time, the system will run on the center two carburetors from idle, bringing the outer carburetors in from around 50% throttle. On a 3×2 you have a a lot of versatility on bringing the outer carbs in earlier or later, but on a 6×2, it’s not that easy because the slider rod MUST be attached to the top hole in the long center lever because the bottom hole is taken by the link to the back-bar. And if you swap them, those back-bar links hit the back carb fuel inlet.

Even then, we’re not completely out of the woods. On a 6×2 progressive linkage, the sliding rods on each bank must join to the front carburetors. They cannot join to the back carbs (as you would usually with a 3×2) because of clearance issues with the back-bar. Why is that a problem? Because on a front-facing 3×2 progressive, with the sliding rod in the top adjustment hole, that sliding rod will rub on the underside of the center carburetor hose (if you use traditional fuel hoses). The good news, though, is that we offer a special fitting to help you out. 9080K-E, our extended Superseat hose fitting, moves the hose and clamp further out a little to leave a gap for the sliding rod to clear. Check out the pictures on our website. You may have seen pics of old school 6×2 progressives with slider rods bent like a big L shape to miss that center carb fuel inlet. Use a 9080K-E and bendy rods are history.

Warning! ….Do not use the linkage in any configuration that will cause sticking and binding, which could result in uncontrolled engine speed, property damage, serious personal injury or death.

Return springs. Make sure all six carburetors snap shut when you lift off at the pedal. We mean it! All Stromberg linkage kits are supplied with our Snapback torsion throttle return springs. They’re almost invisible. They work great and you can get more from your Stromberg dealer (ask for 9154K). Remember you already have the accelerator pump springs helping return the throttle so you shouldn’t need a crazy number of springs. If there is any slowness in the throttle return it is probably at the pedal end or because your swivels are misaligned. Eye the system from above and adjust the levers along the throttle shaft or Back-bar as required.

Jetting. We cover jetting in other How-to’s and the message is the same for a 6×2 system as any other. With engine tune, elevation, local gas laws, ethanol content and more all having a bearing, each application will be different, so it’s almost impossible for us to estimate what you need. So we usually say start with the standard 0.45 mains that Stromberg 97s come with and see how it works from there. Though as a rule you’ll probably need small power valves – nearer the number 71 mark.

Just remember, the main jets come in almost immediately off idle and control the fuel air mixture at cruise speeds. Once you get past around half throttle, the power valves join the party. The power valve controls the amount of enrichment at higher revs. While it does pass through the power valve, the volume of accelerator pump ‘squirt’ is not really dictated by it. In tuning, you might want to try disconnecting some of the accelerator pump lever links (like all outer four at first) to test reducing that top end enrichment and also the amount of at raw gas injected when you pump the throttle. Remember, most 6×2 intakes were designed for racing at full throttle. If you crawl around town and rev it at the lights, you will get wet fuel in the bottom of the intake.

As always, getting the car/engine onto a dyno of some sort will help you measure what is happening and make informed decisions about tuning. One small tip: Once the linkage is set-up, it is often easier to leave it in place and remove the carburetor bowls off the bases to change jets. Keep persevering and you will find a good level of tune that suits your engine and your driving style.

Your link to the pedal. We have said this before, but it’s worth repeating. Stromberg recommends a mechanical pedal link for all multi-carb systems. Ideally, your 6×2 Back-bar can be connected to the pedal via one of the long levers that work the two banks of carburetors. But if these don’t line up with your pedal link, you can add a third long lever to the Back-bar shaft with Stromberg kit 9096K (Long linkage arm/swivel) positioned to align with your throttle pedal ‘pull’ point.

You can download this How-to at the Stromberg Tech Center (click the link). As with all our Tech articles, we welcome customer feedback and other input. Add a comment right here, or email us (tech@stromberg­-97.com) with your thoughts and if it adds to the debate, we’ll add it in.

 

AMBR contender – six chrome Stromberg 97s!

A few years back, we were looking for old pics for our website of cool Stromberg-equipped cars from back in the day. A great contact in California sent us this awesome COLOUR picture of a channelled ’32 roadster at the 1961 Oakland Roadster Show. We had no idea who took it (though I now hear it was Andy Southard), but I thought it was the coolest thing ever – it says everything about what Stromberg means to millions of hot rodders the world over. But the blue colour balance didn’t work for the website and it never made the cut. Then just recently we nearly used it again for our ad in the forthcoming Jalopy Journal book. Note, I said, ‘nearly’…

So let’s back up to October 2011. We get a phone message from a guy named Marcus in CA. I mean, no-one phones us from California! But he had six chrome 97s and was asking about 6×2 linkages. We were still in development then, but we emailed back and showed him pics of our early feasibility prototypes and mock-ups. By December, we had enough parts to send Marcus our first ever 6×2 Back-bar kit. No idea what the car was or anything. Happy customer… on to the next enquiry…

Next up, in Feb 2012, we get the first pics of the Grand National Roadster Show contenders. We make our personal choice. No contest. Sylvester III, the wild red ’32 with the six chrome 97s. I can’t see the attraction in Indy-car looking hot rods myself, but the judges thought differently, I guess. Then in May this year, a new email back from Marcus. I hate the word ‘humbling’. It’s overused, but it kinda fits here:

Hi Clive, Back in January, you sent us a prototype 6 X 2 rear linkage and we would like to say thanks again for your help.  We have recently finished a project using 6 of your new chrome 97’s, a couple sets of your progressive linkage and your “you-fit” rear linkage and couldn’t be happier with the overall look and performance of all of your products.  We have taken the car to a few high-end indoor shows this year and have been getting a very good response and are attracting a lot of attention………(I’ve cut some here)…. I have attached a couple pictures of the car, and look forward to hearing from you.

Two things. One..humility. Guys build my vote for coolest car of the year and talk about “a very good response”. I should say so! I love this car to death. And we want to give huge thanks to Marcus Owens and Paul Shaughnessy of New Metal Kustomz for using our chrome 97s on this car. 2012 was actually a breakthrough year for Stromberg at the GNRS with a bunch of the real high profile cars using our carburetors and other products. So thanks to all those who chose Genuine Stromberg! We know you have a choice… And the second thing? Suddenly it all makes sense. Mystery Marcus, the awesome red ’32, and yes, of course, it’s the very same car as in our blue-tinted 1961 Show picture!

You can read all about the car and its trip to the GNRS 2012 on the HAMB. No point us repeating it all here. Far better to hear from the various horses’ mouths. Click the HAMB link to check it out.

 

Choosing the right Stromberg 6×2 linkage

So you’ve got yourself a cool 6×2 intake, either a new cast manifold like the Edelbrock X1 ram or the Offenhauser Pacemaker 3924 (low-line), or a U-fab or log-type intake, and you’ve stepped up for six 97s. What you need now is a quality, sturdy linkage that won’t flex when you stick your foot in it, and won’t swamp your beautiful carburetors with huge brackets or weird curved linkage rods going in all directions (yes, we’ve seen them too).

Stromberg has 6×2 progressive and direct (non-progressive) linkages to fit pretty much everything out there. This means ready-to-fit kits for those popular intakes that are available brand new. And ‘Trim-to-Fit’ kits for everything else. The direct linkages come complete in one box. And the progressive linkages are modular, so you can always get the right parts for your intake. Here’s how they work…

Choosing the right 6×2 Direct Linkage kit. Let’s get the easy ones out of the way first. Right now, we offer three 6×2 Direct Linkage kits.

Got the Edelbrock X1 ram 6×2 intake? You need our 9261-D 6×2 Direct Linkage Kit. It spaces the carburetors 4-7/8th inch in front of each other and 9-1/8th inch apart across the intake, and there is no offset between the two banks of carbs. This linkage is ready to go, comes almost completely assembled with the Back-bar levers pinned to the shaft and even though it bolts straight on, it still comes with full instructions, of course.

Got the Offenhauser Pacesetter 3924 6×2 intake? You need our 9262-D 6×2 Direct Linkage Kit. This is a low-line intake compared with the X1 so it can give you a little more clearance for low hood applications. It spaces the carburetors 4-3/4 inch in front of each other and 6-1/2 inch apart across the intake, with the carbs on the US driver’s side 3/4 inch offset in front of the other bank. As before, this linkage is ready to go.

Got something else? You need our 9260-D 6×2 Trim-to-Fit Direct Linkage Kit. It will work with intakes that space the carburetors up to 5-1/2 inch in front of each other, up to 9-1/8th inch apart across the intake and up to 1 inch of offset between the two banks of carbs. Believe us, that’s going to cover pretty much every production engine around. How difficult is the trimming? You’ll be drilling and maybe shortening one bracket and adjusting the lengths of the rods. And everything is explained in the Installation Guide included. Download a copy right here in our Tech Center if you’d like to see it first.

Choosing the right 6×2 Progressive kits.

A 6×2 progressive linkage is really just two 3×2 kits plus the Back-bar which joins it all together. With so many different variables between intakes, that’s also how we offer them. Here’s how to order the right kits for your intake:

1. Measure the carb to carb spacing – from one throttle shaft to the carb in front. Then order two kits – one for each bank – of the correct Stromberg 3×2 progressive linkage to suit your carburetor intake spacing. There’s a list of which linkage fits which spacing below. If your spacing is not covered, buy the next size up and trim down the threaded rod between the secondary (outer) carburetors. Trim the right hand threaded end and add more 3/16-32 UNF thread if required.

For this spacing….use this kit

4-9/16inch………..9243PRO

4-3/4inch………….9253PRO (fits Offenhauser Pacesetter 3924)

4-7/8inch………….9251PRO (fits Edelbrock X1 ram)

5-3/16inch………..9245PRO

5-1/2inch………….9246PRO

2. Now add the 6×2 Progressive Back-bar Kit to link both carburetor banks together. 6×2 intakes can differ in the space and offset between banks.

For this intake…………….use this kit

Edelbrock X1 ram………..9261-BB

Offenhauser Pacesetter 3924…….9262-BB

Anything else……………..9260-BB (Trim-to-Fit)

It might also pay to compare the spacing, width and offset of the Edelbrock and Offenhauser intakes (see above in Direct Linkages) to see if they are nearer to your requirements.

Your link to the pedal. Stromberg recommends a mechanical pedal link for all multi-carb systems. Ideally, your 6×2 Back-bar can be connected to the pedal via one of the long levers that work the two banks of carburetors (they have three adjustment/connecting holes at the top). However, if these do not line up with your pedal link, you can add a third long lever to the Back-bar shaft with Stromberg kit 9096K (Long linkage arm/swivel) positioned to align with your throttle pedal ‘pull’ point. Complete with swivel, clamping screw and 3/32” roll pin, the 9096K lever can also be drilled and pinned to the Back-bar to ensure positive location.

You can download this Tech article at the Stromberg Tech Center (click the link). As with all our Tech articles, we welcome customer feedback and other input. Email us (tech@stromberg-97.com )with your thoughts and if it adds to the debate, we’ll it in.