Our classics, no matter how good they are, are old. And that can have consequences that only become noticeable once a specialist has been released. The engine that the owner was so happy with can suddenly be kissed awake and perform better than in the wildest dreams.
Power and capital gains
Technically and economically there is one approach that provides the ultimate answer to all your questions. And that is a visit to a company that specializes in dynamometer measurements. The performance and pain points of an engine are made crystal clear on a roller dynamometer. The professionals who operate the power bank can read and interpret the graphs that appear on the monitor - and the printout of those graphs that always look fantastic on your workshop wall - as a doctor makes a diagnosis for a well-insured patient.
The power and torque are measured on the dynamometer itself
The multi-gas tester that is pushed into the exhaust measures the composition of the exhaust gases. That composition makes a lot clear about the combustion process in the engine. A pick-up around a spark plug cable provides extra information about the ignition and speed. The synchronization of the carburation is checked separately and corrected if necessary.
Our example: Almost 30 horsepower more power
For our story we had access to a very nice example: A Laverda 1000 cc three-cylinder from 1978. A real, honest machine that, according to the information supplied, would have been tuned with the C4 racing camshafts from a Jota. The open air filters in 'K&N' style and the Jota exhaust system were at least the visible signs that something had been done to the engine. The previous owner was a diesel mechanic and said he had always done the maintenance himself. The engine felt a bit messy 'at the bottom', so at low revs.
In city traffic that was downright annoying. That somewhat choppy behavior below 3000 rpm could be a result of the installation of camshafts with sharper run-up profiles and more valve lift. Or it could simply be because the block in terms of nozzle occupation of the carburettors would not be adapted to the aforementioned air filters. From the middle range the engine - when it was warm - ran better. At the top, the case did not continue as nicely as with the C 1000 that the owner had previously owned. We visited Startrick Tuning where Hans van der Starre can analyze power ratings up to 500 hp.
The approach was to check the engine. Not to come to the ultimate top power, but to see if the case could run nicer.
Listening to capital gains
Upon arrival, the engine was first just listened to. The professional listens and analyzes the noise of the camshaft drive, valves and pistons. The response to gas commands also says a lot. The intake interview was then over. The motorcycle was lashed to the test bench with straps. This is a power bank that was developed and built by Startrick itself and where the driven wheel (s) is placed on top of 1 set of rollers.
This has the advantage that 1 contact surface most closely approximates the situation on the road while the friction is minimal. The engine receives the multi-gas meter anally. The cooling air blowers are started. The hearing protection is on.
What is such a wealth bank doing now?
A diagnosis is made about the build-up of the engine power. Quite simply, an indication for extra power and torque is obtained by a better adjustment of the fuel system and ignition in particular.
The first run gives the result that 1000 cc three-cylinder, which according to the manufacturer, depending on the state of tuning, should have between 80-97 hp at the crankshaft…. It delivers 40 hp to the rear wheel. Hans van der Starre takes his infrared thermometer and the engine is started again. It turns out that the exhaust bend of the right cylinder remains about 100 ° colder than the middle one. The first conclusion is that the cylinder does not really participate.
The right spark plug goes out and appears to be sparking. To see the gas slides, the three imitation K&N filters are disassembled. Hans van der Starre looks at things and says "Hey, we will notice that." He points to the sharp transitions in the Chinese imitation filters and the fact that the edges of the rubbers are in the way of the compensation holes of the Dell'Ortos. A look into the carburettors after a turn of the throttle makes it clear that the throttle slides don't really move evenly.
The chokes are checked and found to be OK. The throttle cables do their job. The engine restarts and the cooling fan turns on. The third cylinder now turns obediently and the block already sounds very different. In that strong breeze, the Italian 180 ° three-cylinder suddenly pulls twenty hp more! So the imitation K&N filters destroyed 20 hp! "Now we are going to look a little further."
Because Startrick Tuning is not only the distributor of Dell'Orto carburettors, but also an official K&N air filter dealer, real K & Ns are installed instead of the Chinese 'would be' K&N filters after ensuring that the three throttle valves open synchronously. The digital vacuum gauge is connected and shows that the adjustment of three Dell'Orto's by a diesel specialist does not have to be a success. Hans ensures that the three 'digital mercury columns' on his measuring device march up and down neatly in step. The three real K & N's are screwed on and the engine is started again. The nozzle occupation appears to be almost in order. For ultimate perfection, the throttle needles, in the carburettor and the main jets still need to be tinkered with. These also determine the ratio of gasoline / air. The throttle needle should go down a tiny bit and the main jets could be one size bigger.
A lot of power is enough
But that would only be nice for it. But that doesn't matter to the owner. Main nozzles are for the mixture supply at full gas, and the Laverda no longer needs to work that hard. His three-cylinder engine moved from more than 40 to more than 70 hp at the rear wheel within an hour. And with respect for the 90.000 kilometers that are on the clock, Hans has opened the case to just above the 6000 rpm. At that moment the curves continued to rise unrestrained. So there is clearly more in this block. After adjustment, the three-cylinder engine runs like a very bit of sun instead of a nasty tractor. And that was the point.
Mmm was also thinking about putting my Guzzi on that couch once.
Am really curious.