Cam mod + Carb for HS Questions

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Mr. Minecraft

Mr. Minecraft

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Jan 13, 2012
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Cam Mod:

What is this mod?

What will it do for me?

How do i install it?

Where do i get the parts?


Carb:

People say a Big bore carb is good for the HS 4 strokes. What carb is this? (links help xD)
 
scotto-

scotto-

Custom 4-Stroke Bike Builder
Jun 3, 2010
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Mr. Minecraft said:
The title does say 'For HS'. I assumed that refered to the 49cc Huasheng.

So this cam: http://www.affordablegokarts.com/mm...ode=A&Product_Code=1610&Category_Code=MTRBK49

And this carb: http://www.affordablegokarts.com/mm...ode=A&Product_Code=1160&Category_Code=MTRBK49

With this breather: http://www.affordablegokarts.com/mm...ode=A&Product_Code=1506&Category_Code=MTRBK49

Will noticeably improve the performance of my HS?
Click to expand...
It will with a free-flow exhaust and air filter with the valves adjusted properly.

I'm fresh out of links right now, let me see if I can dig some up?

dnut

EDIT: found a link that might help..... http://motorbicycling.com/showthread.php?t=33958
 
Last edited:
The_Aleman

The_Aleman

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Jul 31, 2008
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A Future Pilot said:
It gives you more power, but I'm not entirely sure of the science behind it.
Click to expand...
Basically the cam's base circle diameter is reduced, effectively increasing the lobe's lift.

Because an engine is basically an air pump, more lift means the valves open farther, increasing the amount of airflow.

Like Scotto said, the intake and exhaust must be modified to take full advantage of this. Valve adjustment is a must with cam swap.
 
donphantasmo

donphantasmo

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Sorry, Minecraft. I didn't understand what HS ment.

I think this would be better in the 4 stroke section. But my knowledge of a 4 stroke cam, it changes when the the intake and exhaust valves open and close. So, it allows the intake to get more air, and therefor changes your compression and hopefully give you more power.
 
The_Aleman

The_Aleman

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Jul 31, 2008
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donphantasmo said:
Sorry, Minecraft. I didn't understand what HS ment.

I think this would be better in the 4 stroke section. But my knowledge of a 4 stroke cam, it changes when the the intake and exhaust valves open and close. So, it allows the intake to get more air, and therefor changes your compression and hopefully give you more power.
Click to expand...
It IS in the 4-stroke section. Also, the camshaft doesn't affect an engine's compression. It only regulates when and how far the valves open and close.
 
donphantasmo

donphantasmo

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Oct 3, 2010
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Middleburg, FL
The_Aleman said:
It IS in the 4-stroke section. Also, the camshaft doesn't affect an engine's compression. It only regulates when and how far the valves open and close.
Click to expand...
If the valve opens after the piston is at top dead center, and close before it goes to full down position, then you will have lower air volume then you will if the valve opens directly at top dead center, and closes right at full down position. More air volume = more compression.

I'm not saying I know everything, Aleman.. I am a Jet Engine mechanic (been since 1999). I'm pretty sure these 4 strokes are with-in my crasp.

I used to work at a Nissan dealership. The first major mod everyone did to a 350Z or 370Z is installing a NISMO or STILLEN cams. They varried when the intake and exhaust valves came open. That drastically improved HP.

BAM!!!.duh.
 
E

Erich_870

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Dec 4, 2009
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donphantasmo said:
If the valve opens after the piston is at top dead center, and close before it goes to full down position, then you will have lower air volume then you will if the valve opens directly at top dead center, and closes right at full down position. More air volume = more compression.
Click to expand...
I'm pretty sure that's not correct. Engine compression is a ratio of volumes. It's the comparison of the volume inside the compustion chamber "when the piston is at the bottom of its stroke, and the volume of the combustion chamber when the piston is at the top of its stroke." Atleast that's what Wikipedia says.

Compression Ratio

Erich
 
Mr. Minecraft

Mr. Minecraft

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It seems to me that if the valve opened at TDC then closed at the bottom of the stroke, there would be more fuel-air mixture in the chamber. If the valve does not stay open for the absolute longest it possibly can, then there will obviously be less air/fuel mixture. When there is more air/fuel, there is a bigger explosion, which means more HP.
 
scotto-

scotto-

Custom 4-Stroke Bike Builder
Jun 3, 2010
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Ridin' inSane Diego, CA.
Mr. Minecraft said:
It seems to me that if the valve opened at TDC then closed at the bottom of the stroke, there would be more fuel-air mixture in the chamber. If the valve does not stay open for the absolute longest it possibly can, then there will obviously be less air/fuel mixture. When there is more air/fuel, there is a bigger explosion, which means more HP.
Click to expand...
Kinda sorta.....it's more about timing really. And compression.
 
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