MOTOR KLASSIK 11/2017 THE CARBURETOR SPECIALIST

Thorsten Ihlo takes care of what he calls “the heart of the engine” in his carburetor factory. So it's a good thing that his work is not just a matter of the head.

Text: Michael Orth

It happens the first time. That was 21 years ago. He opens the engine cover of his malachite green KarmannGhia, locks the hood in place and waits a moment - perhaps the moment it takes, because in it, determination takes its place alongside excitement and the importance of the task. Then he grabs a 14 mm wrench, loosens the two MB nuts on the flange, pulls the Solex-28-PCI off the intake manifold and finally holds the carburetor in his hands.

“I took it apart and restored it,” says Thorsten Ihlo, ”I can still remember exactly how all the individual parts lay in front of me. It fascinated me”. He says that something happened that he hadn't even consciously noticed. “I just realized that it was doing something to me. I discovered my personal comfort zone,” he says today.

Thorsten Ihlo, who runs his carburetor factory as a master craftsman's business for the motor vehicle guild, trained as a wholesale and retail salesman, later studied communication and graphic design and worked in an agency. And he has always been tinkering since he dismantled his older brother's racing bike when he was eight. “I wanted to see how it worked,” he says. “You're crazy,” says his wife, ”you take everything apart.” But also: back together again.

From hundredths to thousandths

There is still the drive to get to the bottom of things, to find out how something works, or why it doesn't, in order to then repair and improve it. He can still go from hundredths to thousandths until it is clear how he can really do justice to the matter. So each individual carburetor: with careful disassembly, thorough but careful ultrasonic cleaning of individual components in the appropriate bath, blasting of the housing, revision, repair or restoration as well as the procurement and reproduction of special parts.

In one case, a housing has to be welded at a crack, in another it has to be re-bushed or face-milled after material has been applied to the flange. The next patient has a rattling throttle linkage, draws the wrong air, has a crooked throttle valve shaft or one that needs to be replaced in the housing, or requires specially manufactured nozzles, needles and gaskets.

Ihlo reaches into one of the black-lined cases in which the overhauled carburetors live as if in comfortable single rooms, and carefully places a Schebler HX in front of him on the workbench, where a revised pair of Zenith 35/ 40 from a BMW 3.0 CS is also waiting for a final inspection.

“This Schebler here,” he begins, ”is 100 years old, 100 years old, and nobody had touched it before it came here for a patina restoration. You then think very carefully about how you should remove the soldered throttle valve from the shaft. What solder did they use 100 years ago? How will it react to heat now? And you only have one attempt. If you don't think carefully, the part is broken and gone. The work is very complicated, although the carburetor is actually simple in design. The carburetor batteries for a Maserati or Ferrari twelve-cylinder or the two on the other table are much more complex.”

The individual parts of two Solex twin carburetors from a 190 SL are spread out like twins on white paper towels, arranged as if in pedantic order. How many? “That depends on how you count them,” says Thorsten Ihlo, picking up one of the diaphragms. “It's already bolted to the carrier. That could be considered one part”. Or take it apart, then it would be six parts. But that's not the point, it's not about the number of parts or the complexity of the design. It's about the interaction of all the parts in each individual case.

“As I see it, the carburetor is the heart of the engine. The best engine is nothing without a suitable carburetor. But the carburetor environment is as important as the carburetor itself. Two thirds of all problems with the carburetor are not due to the carburetor itself, but come from the intake tract, the exhaust, the engine, the valve clearance or the ignition. It all has to fit together, it has to be coordinated.” Thorsten Ihlo raises his eyebrows behind his glasses. “The problem is,” he then says, ”that you tend towards perfection when you do something like this. But there's no such thing as perfection.” It doesn't exist, he says, as an exactly reproducible calculation parameter.

Because on the one hand, every carburetor is just an atomizer. “It mixes fuel with air, that's all it does”. This matter-of-fact approach is as true as his assertion that he “doesn't do anything special. It's just a craft. I love doing it and I feel it's a privilege, but you can't overdo it.”

Living beings

On the other hand, each of the carburetors he devotes himself to, which in some cases he even has to rebuild two thirds of the way through, is like a living being. Thorsten Ihlo also acknowledges this: “It drinks, it stinks, it makes funny noises and needs a lot of attention. Everyone is very individual. They all have their own character.” No two are the same, even if the model is the same. “You can get lucky with standardized bushings or gaskets. But as a rule,' he explains, 'that doesn't work.

It doesn't work because the 40, 50, 60-year-old or even older carburetors have tolerances that Ihlo says are “hilarious” due to the production machines and methods of the time. It almost can't work, you think to yourself, as imperfect as it all is. But that's the case throughout the engine. Now you go and perfect every component. You put everything together and think it works perfectly? Not at all.” It's not that easy.

Coltrane's saxophone

It only works with a great deal of empathy and a precision that can give the imperfect just the right amount of space to harmonize with the other, equally imperfect parts so that the whole thing works perfectly in the end. And perhaps there is more to it than mere craftsmanship, perhaps there is a little bit of craftsmanship in it.

“I'm just meticulous,” is all Thorsten Ihlo says. The carburetors that he has overhauled do not contradict this. The SU unit of a 4.2-liter E-Type rests in one of the boxes, while a pair of Solexes wait in another until they are allowed back under the hood of a Porsche 356. Ihlo has just replaced the double Weber for a racing Alfa on the old tester with the Zenith of a Commodore A when he opens another case and removes a Dell'Orto DHLA 40. Converted for use on a motorcycle and completely chrome-plated, it looks like a musical instrument surrounded by the aura of a work of art, Dizzy Gillespie's trumpet, John Coltrane's saxophone.

“For me, working with the carburetors has something meditative about it. I'm usually a rather impatient person. But here I can really withdraw into what I'm doing. But it's not about me either.” Thorsten Ihlo emphasizes this again and again. “My work is the focus, not me.” At first, that sounds as if the one can be separated from the other. But it's not. You have to listen to him carefully. Thorsten Ihlo doesn't speak in such a way that the subtleties don't matter. He doesn't say “the work”, he says “my work”. He is in his work, it is in him. ■

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