engine tweeks to increase hp

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i will be building a cylinder spacer approx 7.5mm thick. basically you want to get the top of the piston flush with the top of the cylinder. the stroke of the motor that the cylinder was designed for is 43mm. so i'm really only adding 7mm to this cylinder. i think that the port timing will be very close to what i need for 10,000rpms.
to balance the crank i am adding 52% of the weight of the small end of the rod, piston, wristpin, etc to the lower half of the rod and bearing. assemble the crank with a bob weight and true the crank. balance. assemble with rod, true crank again, and fusion weld crank pin to flywheels and true again. wait tell you see the pipe i build for this little beastie.
 
i had to make this cylinder spacer 7mm thick, and had to match port the transfers to the cases. i was a little worried at first because i decided to run the cylinder backwards, (carb in front because of intake obstructions), and the ports were offset to opposite sides of the motor from each other. by the time i finished i was very satisfied with the way they turned out, very smooth transitions.


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i put this sucker on with hondabond, so its basically just an extension of the case now.


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i cant wait to build this pipe, i will have batteries for my camera.

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just picked this mikuni up today from a buddy, it came with an intake, phenolic spacer, and a k&n filter for 20 bucks. it's perfectly huge

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for those out there who are curious, stock cylinder timing with this particular stroke, is 176 on the exhaust and 136 on the transfers. i was very worried that, with the increased stroke my timing would be too high for a fixed gear, but it wasn't and i am happy.
 
ok, clay, you have done ten times more than ive seen ANYONE do with a ht engine. that mikuni is really gonna help open things up on that little engine. the port timing is something that should make a huge difference, so im curious to see how it helps you. HA by the way, im drooling over that humongous exhaust port. i oughta open mine up a bit with a dremel today... oh, i put a walbro hda 63 on mine with a goped intake spacer that i port matched with a dremel. ill fire it up today and let you guys know how it goes.
 
the first 21 cones are of the 2deg taper variety, the last three are the start of the 6deg taper, which will continue for about 8 more inches. then a little over three inches of 12 deg taper, followed by 5 inches of chamber. lastly a baffle of undecided taper.


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Speedracer, How's the puch head on your motor? did you modify the squish band at all?
 
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