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· Registered
55 Posts
Discussion Starter · #1 · (Edited)
Wanting to Know what the best Cam Shaft for my set up, I have something a bit different then most guys in here I have a 2003 Honda 300EX Engine That i installed into a Baja Dune 150 Go Kart/Buggy and I was wondering since I have the Engine modded the Things weighs about 550ish it's pretty effing quick it will stay with Piped and jetted 400ex's no problem all day and Night. What would be the best cam for this? I List all the Modifications I have done already Down Below. it is a Major Torque Box.

The Complete Mod List on this Engine is.

1. 3mm Wisco Oversized Piston.
2. Ported & Polished Head, Polished Valves, Polished Combustion Chamber & Top of Piston is Polished.
3. I have a Tusk HD Clutch kit "To Help With Te Weight"
4. 35mm FCR Carburetor from a YZ250F
5 Adjustable DC Fired C.D.I. with adjustable Rev Limiter & Timing Curve from 8500RPM to 9500RPM
6. 28" Long Head Pipe
7. Sprocket gearing is 13 teeth to 31 teeth.
Tire Size for the Rear is 20"

· Super Moderator
4,879 Posts
The best cam for your "set-up" is totally dependent on what your performance goal is.

If you use a HOT CAM, the choice is simple - they only offer a stage 1 cam for your engine.
Exhaust Duration (Degrees at 1mm): 232.00
Exhaust Lift (mm): 7.50
Exhaust Lobe Center (Degrees): 103.50
Exhaust Valve Lash (mm): .15
Intake Duration (Degrees at 1mm): 238.00
Intake Lift (mm): 7.05
Intake Lobe Center (Degrees): 103.50
Intake Valve Lash (mm): .10
Excellent midrange and top-end increase. Uses stock valve springs and rockers.

Generally speaking; you change the cam profile to get back top end lost by increasing the bore and/or stroke which increases bottom end power. A larger carb helps with top end RPM at the expense of low end throttle response. Larger ports complement larger valves. Normally, only the exhaust port is polished - polishing the dome of the piston and cylinder head is nice, but performance gain if any is fractional - polishing the intake port robs power. Raw fuel does not burn, it's the vapors. A polished intake port (and valve) may smooth flow, but droplets of fuel simply roll across the surface and are wasted. A polished intake is advantageous with direct fuel injection, but is detrimental with carbureted engine. Likewise, a larger carburetor has a lower velocity of air flow and vaporization of fuel becomes less efficient.

If you require a other than an "across the counter" offered camshaft, consider contacting Web Cam who offers several different profiles, but you will have to send in your rocker arms for a hard weld refacing or Megacycle Cams for a custom grind and hard weld of your rockers. Only the Hot Cam does not require hard welded refaced rocker arms, but it is recommended that new rocker arms be installed with a new camshaft.

To the best of my knowledge, the information given is correct and true, but I am not a camshaft guru, I have limited experience with the three companies and technology changes rapidly. I strongly suggest you contact each manufacturers tech support before making your final decision.

· Registered
55 Posts
Discussion Starter · #5 · (Edited)
Thanks a bunch for the long response very helpful. I am looking for more Top End Torque since Low and Mid has Tons "and I mean TONS of power" I just want the top end to be able to have lots of Torque as well So it has a "All Round Power band" because if it were to be Dyno'd "I am Guessing the torque would drop off at about 6500 RPM's" the intake is only Polished 3/4 of the way through and I did that because "yes I do know about the fuel vaporization" fuel needs a little bit of Rough Texture I am very knowledgeable to Engine Building and flow Characteristics. The intakes valves being Polished that is a "Great point didn't think about that though" Also Yes Larger Carb loses Velocity, but I have the "Intake Boot" custom made it tapers right before entering the Cylinder Head to help Squeeze the incoming Air and Fuel into a Vapor. I was just more curious of Which Cams do what and you have answered my question I appreciate that a bunch man! Basically the engine in this buggy I am just doing any of the "Smallest Tweaks" to get as much power out as this little 300 can push for just for Pride to say I Build this, and of course, it's always fun because it will turn heads. ;)
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