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My 1000S page. 2   (click here for page.1)

Conversion to the Sport 1100 engine

During the dismantling of the Sport 1100, it already became apparent that this motorcycle had a tough life, so did the engine. The following has been replaced:

-Exhaust valves and all valve guides

-New buses in the rocker arms

-Connect rod bearings

-V11Sport cylinders / pistons (nicasil coating was loose)

-Oil pump (screw thread broken)

-Camshaft (for more torque)

-Timing chain

-Timing chain tensioner (Stucchi tensioner)

-Digital ignition (sensor on camshaft gear)

-Oil lines

Optimization of the engine

The engine has been further optimized by a German tuner. The combustion chambers are refined, so that the left and right sides have exactly the same volumes and the compression has been increased to 1:10.5. Another camshaft should provide better torque at lower revs. The cylinder heads are fitted with a second spark plug to further optimize combustion. I did the rebuild myself to reduce costs. The new camshaft has additional oil outlets on the cams itself, for optimised lubrication. The original holes next to the cams are now closed. However, the finish left something to be desired, because the chips were still in the oil channel of the camshaft. That could have ruined my overhauled engine right away. The "tuner" didn’t check and neither was impressed about it. The camshaft itself was not a example of good workmanship either, the surface had several tangible flat pieces. That would wear off quickly, he commented. I didn’t like to mount this camshaft, but there was no time to wait for another camshaft from the grinder, becaue the engine had to be ready for my holiday.

Distribution cover

To get the Sport 1100 engine to fit into the 1000S frame, the original distribution cover of the 1000S had to be used, otherwise the attachment points with the frame do not match. This will fit the 1100 block without modification.

Crankcase and oil cooler

In order to be able to mount an oil cooler in the future, I have mounted the crankcase of the V11 Sport, which already has all connections. According to the tuner, the engine would need an oil cooler, which turned out to be correct, the engine got warm for Guzzi standards. In the end, the V11 crankcase was exchanged after a short time for a special crankcase from Moto-Spezial, which has a larger volume and cooling surface. Other pluses; due to the v-shape, it is less prone to suck air through the oil pump during acceleration (weak point of the V11 crankcase). The oil filter is on the outside, easier to reach and providing some extra cooling.

Air filter box

The separate K&N filters have made way for the original air filter box. The filter box has the advantage that the air supply is larger and there are fewer swirls compared to the filters directly on the carburettors. The filter box has been modified, the snorkel at the front has been left out and an extra hole has been made on top of the box, to hinder the air flow less. The air that now enters through the top is unfiltered, the coarse dirt is only filtered through a piece of fine mesh from a kitchen sieve. The disadvantage is that a bit more dirt enters, but in heavy rain the engorged air filter is no longer an obstacle to get enough air in.

The result

The first start went without problems, the engine actually ran well right away. Now the engine had to be run in first, but there was already noticeably more torque. To prevent the mixture becoming too lean (hot engine) during running in, the main jet was deliberately kept larger. After running in, the motorcycle was placed on the test bench to make the jetting just right. The main jet has become a bit smaller and the idle jet has also been changed. Unfortunately, during the power run, it emerged that between 3500-5500 rpm there was still a significant dip in the torque curve. The maximum torque was also disappointing, this did not resemble the promises being made with the original exhausts: 81.9 hp / 7600rpm and 84.2Nm / 6500rpm (measured on the rear wheel). Later I had stainless steel exhausts made, internally identical to the original exhausts, but with a somewhat larger diameter. The exhaust pipes were fitted with an extra balance pipe underneath the alternator, just like the Le Mans 850. According to the documentation good for more torque at low revs. This already gave an improvement: 81.8 hp / 7400rpm and 91.5Nm / 6055rpm (measured at the rear wheel). Only the torque has increased by 8.6%, but that was exactly what I hoped for.

vermogensgrafiek.jpgConclusion in 2008

The dip in the torque curve remains persistent, that's just the way it is, nice promises do not always come true. Unfortunately, the dip is at speeds that are often driven and therefore clearly present while driving. Not that I have much to complain about, compared to the original engine, it now has significantly more power and torque. With the knowledge that a ‘flat’ torque curve is possible as well, it kept me thinking. The parts that I have taken as a package from the tuner do not deliver what is promised, or in other words, are not optimally matched.

                                                                                                Dyno chart: measured at the rear wheel.

The sequel in 2012vermogensgrafiek_2012.JPG

With the special camshaft, the valve overlap should actually take place 3-4 degrees before the dead center. This can be adjusted by drilling several holes in the camshaft gear in which the locking pin falls. By mounting the gear on the different holes, the hole can be chosen that is closest to the desired value (in simple terms). The tuner has been so sloppy to leave this out. So I decided to take the engine apart again to put in the finishing touches. Now that everything was loose, I also had the crankshaft balanced together with the flywheel, because the engine still vibrated considerably. I also bought a different ignition, which is now from Sachse http://www.elektronik-sachse.de/. Unfortunately, this very helpful technician died in 2013, but his work is continued by a new owner. Balancing was not really a success, the vibrations only changed to a different kind. The adjustment to the camshaft has had results compared to the last measurement: 85.1 hp / 6918rpm (+ 4%) 98.4Nm / 5714rpm (+ 7.5%) (measured at the rear wheel). With 10% loss in transmission, this is about 108 Nm and 94 hp at the crankshaft.                                                                         

                                                                                  Dyno chart: measured at the rear wheel.