Engine tuning
From Owner's Document
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To confirm differences check out your bike's sector at the bottom. Light blue for 470/501, light yellow for 550/650.
[edit] General[edit] Con rodCon rod lengths, big end sizes, and piston heights
[edit] More rod lengths - KTM121mm rods std sxs 540/ 05. 126mm std rod from stroker crank. 129mm std 525 rod. 131 falicon special, 134 mm falicon knife edge. [edit] Alloy composite rodEngine hardwear uses these in his motors and the typical weight reduction is:
[edit] Crankcase heightsWe can't confirm exactly but the 501/550 cases are thought to be 9mm taller than the 400/450/470 cases. The 630/650 cases are 29mm taller than the 400 cases. [edit] Piston heightsThe earlier 470/550/650 piston was some 3mm shorter above the L/E pin than today's pistons from the 450/550/650. (Hribman) The 470 is domed whereas the 550/650 were flat.
[edit] CompressionThe BV head has an additional 1.8mm of aluminium at the face and a larger machined out combustion chamber meaning the head alone holds another 10cc (27cc to 37cc). This heavily reduces compression if fitting the BV head to the 400. It is a future test that i see how much of this "1.8mm" can be machined away to take the true benefits of the bigger valve heads. Here is a good photo of Lineaweaver's 37/32 head with it's beryllium seats:
[edit] Thicker headgasket - OEM21 200 319-01 Cylinderhead gasket 400 (thick) -01 21 200 231-01 Cylinderhead gasket 400 -02 21 200 320-01 Cylinderhead gasket 501 (thick) -01 21 200 232-01 Cylinderhead gasket 501 -02 21 200 321-01 Cylinderhead gasket 470/550/650 (thick) -01 21 200 233-01 Cylinderhead gasket 470/550/650 -02 (joeUSA) [edit] Standard head gasket thicknessis always .056" or 1.4mm. This will compress to .050" or 1.25mm in use. [edit] Close ratio sixth gearTaken from the FC 470 or 550 gear cluster. Instead of a 27/20 ratio it's 25/21 for a closer top gear. However when running 13/48 or 14/51 for a nice first gear in the woods; sixth is too low in the open so this might be the wrong mod to do! Here are the old part numbers: Input shaft = 240 076-01 (25 teeth) Output shaft = 240 086-01 (21 teeth)
Here is a table of the gear teeth on the boxes from 2001 - 2008
Here is a table of the FC gearbox 1997 - 2000
First is much, much taller, second is much taller, third is ever so slightly taller, fourth is ever so slightly taller, fifth is exactly the same, sixth is shorter. All the like-for-like gears are interchangable. To find out if a gear from elsewhere is the right one you will need to look at the gear that presently holds that position! [edit] Coolant
[edit] Husaberg 400/450 ModelsHaving checked the squish it was an awesome .046"(400) which is 'racing stuff' (.040" minimum). The valve to piston is over 5mm (the minimum gap would be 1.5mm on both I and E) on both sets of valves which will allow possibly for someone to accidentally get the timing one tooth out or stronger cam. The springs are very powerful but need to be 'due to the flanks of the cam' (Lineaweaver) which creates heavy inlet valve 'tuliping'. Before tuning make sure the cam rollers, the camchain, camwheel, tensioner blade are upgraded and the valves are in good shape. See Wear items red alert. The pairs of Inlet the exhaust valves of the small valve (35/27) head sit 4mm nearer than in the big valve (37/30) head. This makes it very difficult to put the larger exhaust valves (30mm) into the SV head as the seats are nearer to overlapping. This also explains why the heads don't share the same rockers. [edit] Bigger valvesThe '02 400 had 35/27s standard, the later 450 now has the-KTM-like 35/30. Lineaweaver sells 28mm exhaust valves but I fitted 29mm exhaust valves and ported to 100% size of valves(cut down 30mm valves from the BV head). This gave a good increase above low revs (say 4,000rpm). Larger Inlets at this stage didn't appear to be needed and so with the inlet valve seats '3-angle-cut', the head ported, devcon used to fill it in the 'anti-chamber' another increase in power was clearly felt. But the engine had a flat spot, typically at low revs in second gear: this was cured with an open tailpipe for low rev scavenging and cured this completely. [edit] PortingThe inlet port area needs to be as near to the inlet size (35mm) as possible. The 400 is overported around the branch area and copious use of devcon aluminium paste is required along with reprofiling. This gives more bottom end, midrange and stops the hesitancy that the larger exhaust valves had created. This is due to the increased airspeed and stopping low speed back pressure through and up the inlet ports! Just by putting my hand over the tailpipe slightly; the carb slide would rattle! [edit] CamshaftsLineaweaver's LX1 and LX2 camshaft aid valve gear life, increase power. Visit Dale Lineaweaver's Homepage and see this UHE Forum Thread. The "01" cam is fitted on all 400's as standard and is mild. For real go the rider has to "cog it down one" so the "53" cam (from earlier FC400 and 550/650) is stronger with 1mm more lift and more duration. The engine pulls a gear higher with the '53' cam. The '53' cam is the same as the '55' cam (only found in the 501 engine) but is 5 degrees advanced of '55' cam due to cylinder deck height of that engine (Lineaweaver). The LX2 lineaweaver cam is better (SOTP) than the '53' cam but has the additional benefit of reducing the valve train loading. In tests the bike could be left to lug in a taller gear, was far better in rollon in gears 3-6 especially. Dale's cams have convex flanks and a sideview of the two cam profiles can leave you in little doubt! Todays new generation OEM cams STILL have concave flanks and have only marginally reduced the acceleration pressure on the cam follower bearings. Dale recommends the LX1 cam for engines of around 500cc+. Increased power comes in from 4,500rpm and due to overlap and gas wavelengths an open exhaust MUST be used. Lobe centres for cam timing are:
OEM camshafts 820.36.010.000 and H-200.342.08 share identical profiles. The later unit is shipped with a matched auto de-comp lever. 1mm lift / 0 Lash / Straight Up Intake Open 19° Intake Close 67.1° Intake CL 114.9° Exhaust Open 98.8° Exhaust Close 17.9° Exhaust CL 115.1° Tornado Cams To clarify, on cams and their power characteristics. The G1 cam (which I don't have) is a stage 1 cam for the standard 650 (2002) bike with a race pipe and pumper carb. The G2 is a stage 2 cam for a 650 with a JE or otherwise high comp piston (a must). The G3 is a very long opening high lift stage 3 cam for a bigger than 650cc berg with all the above also. None of the GW cams will work well in a standard piped Berg (Supermoto Husaberg). [edit] To check the valve timingTurn the engine to TDC on ignition mark, check both lobes are up symmetrically. Lay a ruler diagonally across the lobes and it should be absolutely parallel to the top face rim of the head. To change the valve timing, you must slot the holes in the cam gear to allow adjustment. It may pay to have the ruler tilting down toward the floor in front of the bike very slightly. This will actually level out as the camchain stretches. If the camchain link isn't where you want it, turn the engine over 3/4 times until it is. It moves on a bit everytime. [edit] Lighter valves, springs, collets and capsThe factory runs Ti valves as well as Ti collets and alloy or Ti caps (Lineaweaver can supply). Dual straight valve springs are used from a KTM450SX. The weight differences are: INLETS: Steel 35mm=48G, Ti 37mm=30G: EXHAUSTS: steel 30mm=42G, Ti 32.5=26G (Bergoroadracer)
The seat pressure is the same and the peak pressure is 1/3 of OEM. This will increase the rocker arm cam follower bearing and cam lobe life (Lineaweaver). The springs should only be compressed to a certain height, this is known as the 'Installed/nominal spring height'. The installed height for the kit is 29.65 - 29.9mm. To measure this: fit a valve in the guide, a cap with collets and measure the gap between the spring's seat and the underside of the spring cap. With the use of the shims and a lathe you will get the correct installed height. [edit] But....The inside of the camcover on the '01-03s need the rotary file putting over a small area because the spring caps touch slightly (Belgiquebastard).
[edit] Cam timing adjustmentIt's possible to file the camwheel bolt holes oval. [edit] KTM cam anyone?The KTM cam gear shoulder is 2mm less(Photo reads -2mm). The berg cam shoulder is the same width as the old aluminum cam gear, while the KTM cam shoulder is the same width as the newer steel cam gear at the shoulder. The 2mm difference also corresponds to the Decompressor length and the placement of the cam gear side bearing. To make one work you would have to use a KTM decompressor(~$20), sleeve the water pump shaft to the Bearing ID(since the bearing needs to ride beyond the original bearing placement for proper bearing support in the Berg head), place a 2mm spacer between the bearing and decompressor, and cut extra amount of water pump shaft off. I have done all the measurements, but have not yet modified and tried it. (Powerfiend).
[edit] Ignition Marks on flywheelThe ignition timing marks are often found to be out by as much as 8 degrees so check this using the 'dead-stop' method. Find TDC and mark the flywheel. Adjust the ignition knowing that timing changes x 2 in the unit (see also Troubleshooting and fettling). [edit] Other ideas!When modifying the bore, use a headgasket with a 1mm larger diameter hole than the bore. Cometic (USA) have patterns (Lineaweaver) Running without the counter-balancer is fine, it vibrates at idle and then disappears at medium revs. However when 'revving out' the bike vibrates badly and tires the rider quickly. The conclusion? In for enduro and normal use, out for SM and MX perhaps. There is no power gain anyway unless the crank assembly is rebalanced. The 400 crank should NOT be stroked. (Lineaweaver) [edit] Stroker cranks
[edit] Balancing the crank assemblyWhen removing the counter-balance the crank should be re-balanced to a factor of 70% plus or minus 10% (Lineaweaver) a spacer can be made to replace the bearing or just use the inner race.
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