How much of a power gain can I expect?

Clayon

Clayon

#1
#1
I know this question must have been asked before but when I searched I couldn't find what I was looking for. :doah: Anyway, I bought a black 6.5hp honda clone motor. I am doing these mods to it:
  1. K&N style air filter
  2. Header
  3. Re-jet carb
  4. 140 e-tube
  5. Crankcase breather

I know, I know very basic, but how much of a performance gain is there in doing this? Like would the horse power rating increase a bit? :shrug:
 
joekd

joekd

Active Member
#2
#2
Doesnt matter the actual power gain in numbers, it will pull stronger and the header will make it sound so much better. This is what really matters.
 
outcrydrummer

outcrydrummer

Member
#3
#3
Yeah you will increase the hp rating a bit with those mods. I'm not guessing much but probably 1 or 2 horses I would imagine. All I hear is how restrictive the stock intake and exhaust is and coupling that with the fact that you will be jetting and getting a new e tube I would say you'll be doing alright for the money.

those are the same mods I plan to do to my honda clone here in the very near future. Well except for the crank case breather..... not sure I understand what mod your talking about there.
 
1BadFox

1BadFox

New Member
#5
#5
Not much bro. A lotta da trick is in the tune and airflow. Think of the engine as an air pump. Thats all it is. The more air you can move..... the more hp you make. To move air you need to have the valves open enough to get more in. Then once you do get more air in..... it needs to be met with the proper amount of fuel.


A cam with higher lift gets the valves to open more. Or for cheap a ratio rocker will do the same trick to a point. Compression makes power. More Compression is forcing the air and fuel mixture into a smaller space. Remember..... lots of air......the most fuel for the job......squeeze it into a small space..........and BOOM shaga. You gots da powa!. We will talk about getting rid of it through exhaust later.

For now...... concentrate on that.
 
texasfabguy

texasfabguy

New Member
#6
#6
At 3600 rpm it would be 7.3hp with a torque rating 6.9 FTP. With the right gearing and a good tail wind 51mph down hill.












I don't know what I'm taking about.....:eek:ut:
 
O

oldbugger

New Member
#8
#8
I couldn't say either but I did one of mine in stages and went back a step a few times, trying different combinations just to see the bolt on difference.
A simple change to the freeflowing air filter does make the biggest difference in power however it comes on pretty quick and not all that smooth, hence the reason for installing the 140 tube (this assumes you already rejetted the main and idle jets when you added the KN type air filter).
BTW ANY freeflowing type air filter is good, even it is a no name and only costs 12$.
Your exhaust will not add to much to your need and feel for speed until you really push that engine. That means your uh sorta bypassing the speed control (governor with a stright link) to gain the breathing advantage of a exhaust header.
I run a tach and bypass the gov and keep it to less then 4.5K RPM and that keeps my speed down to a sane level. Sane level is your bouncing down the street at 30+mph on tires that were made for a garden tractor with no suspension and only one poor A**rear brake and hanging on for dear life (were talking a bad lawnchair with a engine on it! Remember speed is on a 6.5+ is in many cases a matter of gearing.
But if you add the exhaust it sure sounds mean...and even sounds "Faster", but to really take advantage you need the billet rod and flywheel, valve springs to fully utilize the effects of the exhaust (I just have them cause the add a cool factor) and it allows me to "hide" my fuel tank under the seat so I have a "All engine" effect.
Crank case breather is nothing more then a big gas filter from Kragon plugged onto the breather line, works on karts fine and is cheap, does the job of keeping from blowing oil over things and also keeps low flying birds, bugs and sand etc out of the internals.
 
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Newoldstock

Newoldstock

New Member
#9
#9
Add some compresssion.
14cc head from any 5.5 clone will make the biggest simgle improvement in performance and enhance the VE and fuel curve imrpovements of your proposed build Clayon
 
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