I was thinking about the saame thing, a ram air intake tract! Not sure what angled pipe to use though
Better air filter
- Thread starter BoardTrackBomber
- Start date
I tagged on to this old thread because the title was good and it had some good links to Silverbear's excellent air filter designs.
I pulled my engine apart for a little look see and to tweak my transfer ports.
With only 5 tanks of fuel in this engine I was disappointed to see that the intake side of the cylinder and piston are scored. This is from dirt entry because there is almost nothing on the exhaust side and there is grit in the intake tract.
One earlier poster mentioned about running with no filter: "so what, I'll replace the piston and ring".
Well, add the cylinder to that too, it is damaged beyond re-use. I do a lot of dirt road and off road riding, and it is cold and dusty at present. The stock filter is not up to the task. With the well scored cylinder, ring and piston I experimented with oil mix ratios yesterday and discovered 32:1 worked better than 40:1 or less. I am guessing because more oil helps seal the scored cylinder. I ran some 20:1 today with a new filter but it didn't get any better so I am sticking with a tank of 32:1.
I made a new filter pad with a finer foam, about 1/4" (6mm) thick from a scrub pad.
I could breath through it freely and made it slightly oversize to seal well all around.
Results were not great. Top speed of barely 55kph and sluggish.
I packed 2 stock black filter pads into the housing and got 58kph, almost the same as the 58.8 I got with one stock pad and 58.5 with no pad in it (what does it matter now the cylinder is scored?). Taking the the filter housing off altogether I got 61.2kph which indicates it has a restriction or resonant effect.
So - I need a better filter housing and a better filter material to keep the dust out, and I would recommend other China Girl - Grubee - Happy Time motors consider replacing the stock filter ASAP.
Anyone else have this cylinder wear problem with the stock filter? Suggestions?
Steve
I pulled my engine apart for a little look see and to tweak my transfer ports.
With only 5 tanks of fuel in this engine I was disappointed to see that the intake side of the cylinder and piston are scored. This is from dirt entry because there is almost nothing on the exhaust side and there is grit in the intake tract.
One earlier poster mentioned about running with no filter: "so what, I'll replace the piston and ring".
Well, add the cylinder to that too, it is damaged beyond re-use. I do a lot of dirt road and off road riding, and it is cold and dusty at present. The stock filter is not up to the task. With the well scored cylinder, ring and piston I experimented with oil mix ratios yesterday and discovered 32:1 worked better than 40:1 or less. I am guessing because more oil helps seal the scored cylinder. I ran some 20:1 today with a new filter but it didn't get any better so I am sticking with a tank of 32:1.
I made a new filter pad with a finer foam, about 1/4" (6mm) thick from a scrub pad.
I could breath through it freely and made it slightly oversize to seal well all around.
Results were not great. Top speed of barely 55kph and sluggish.
I packed 2 stock black filter pads into the housing and got 58kph, almost the same as the 58.8 I got with one stock pad and 58.5 with no pad in it (what does it matter now the cylinder is scored?). Taking the the filter housing off altogether I got 61.2kph which indicates it has a restriction or resonant effect.
So - I need a better filter housing and a better filter material to keep the dust out, and I would recommend other China Girl - Grubee - Happy Time motors consider replacing the stock filter ASAP.
Anyone else have this cylinder wear problem with the stock filter? Suggestions?
Steve
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