Cold air/ram air intake

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Nate D

Nate D

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Jun 25, 2009
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So coming from many years of car tuning including extensive work and knowledge on turbos, one thing I am a very firm believer of is having a good intake set up. These china girls with their intakes in the rear get the used and abused warm air after it has been heated by passing over the cooling fins. I rigged up a scoop which delivers air from a much cooler location. I notice a slight power increase at higher speeds and a 1mph increase in speed. Throttle response seemed better at lower speeds and slight torque increase. The mod was free just used some tubing, adhesives/sealers and a soda bottle. LOL Would love to see some other mods of this I'm sure someone can come up with some even better ones given a little more time. I made this in half an hour. Comments? Do check out my ride as well.

Getting much cooler air to that carb now.
 

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BarelyAWake

BarelyAWake

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Jul 21, 2009
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Created for entirely different reasons lol, it would serve a similar purpose save the "ram air" effect, I thought ya might get a kick outa this: http://motorbicycling.com/f4/remote-airbox-intake-silencing-cheap-10967.html

I would like to mention that while "ram air" intakes are effective - they can lead to a lean condition at speed, best to keep an eye on that plug & compensate w/needle clip settings if needful... tho it's true that the NT/stock kit carbs (not the new CNS tho) are prone to a rich condition anyway lol
 
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bairdco

bairdco

a guy who makes cool bikes
Aug 18, 2009
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here's the thread i made about it: http://motorbicycling.com/f38/backwards-engine-experiment-1939-colson-13458.html

i got the idea from Norman. he's got a thread on it somewhere but i can't find it.

in a nutshell, you need to reverse the barrel, and match the transfer ports from the barrel to the case.

i reversed the piston, too. it looked like the ring gap would hang up on the intake port.

the head itself doesn't matter, it works either way.

then you need to bend the exhaust and i had to make a shorty intake to make my carb fit.

i've had this motor on for about 9 months with no problems at all. well, the left side of the case cracked when my chain broke, but that had nothing to do with the motor being reversed.

it is a little harder to start, but other than that, i think it's awesome.

i really doubt there's a "ram air" effect, though. just doesn't go fast enough to take advantage of it.
 
Fulltimer

Fulltimer

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Aug 13, 2010
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I agree that you can't get a true ram effect but it does have to help to some degree. It would be forcing more, cooler air, into the carb. It might be so small of an improvement that it can't easily be measured though.

Terry
 
bairdco

bairdco

a guy who makes cool bikes
Aug 18, 2009
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living the dream in southern california
i think the same thing. i've ported and "blueprinted" (not like you really can actually blueprint one of these, but i've cleaned them up) motors and ran them forwards and backwards, and the backwards ones seem to have more power and run smoother.

the shortened intake helps alot, i'm sure, and just having a free-er airflow around the carb probably helps, too, instead of having the carb crammed up behind the motor, breathing in hot air.
 
ferball

ferball

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Apr 8, 2010
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What would happen if you just but the exhuast on the back and the carb on the front? The port are the same, and there are no valves to worry about, or am i forgetting something?
 
Nate D

Nate D

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Jun 25, 2009
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auburn, wa
drhofferber said:
here is what i come up with...the large hose is the way to go...make sure good filter system...
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Hey drhofferber I love your set up. That is kind of what I had in mind too but wanted something right now like within the hour you know so I worked with what I had lying around. I might later on make another one like yours but instead of the rigged tubing use a more smoother one. Was thinking of placing a heatsink fin from a cpu cooler in the scoop area to cool the air further.

A comment, great feed back everyone we know these motors do not get much power when "blown" but definately everyone agrees it is well known cooler air does affect performance. I live in WA the performance on a cool wet day is very noticeable compared to a hot day in the 90's the air temp is one of the factors. If anyone else has any other mods or set ups they did to get cooler better air please post would love to see.
 
Nate D

Nate D

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Jun 25, 2009
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auburn, wa
bairdco said:
if you really want to experiment with the ram air effect you need the carb to face in the proper direction...;)

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LOVE IT!!! Great mod, you are getting some good cool air ever think of making a custom cowling possibly to direct even a little more air? If not the current set up you have is fine if you want more of a stock looking engine, very clean. Will have to check out your post.

The only concern I have though is I really really like where my exhaust is did you see how it wraps right down the bottom of my frame, you ever burn yourself on that?
 
D

drhofferber

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Jun 22, 2008
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Nate D said:
Hey drhofferber I love your set up. That is kind of what I had in mind too but wanted something right now like within the hour you know so I worked with what I had lying around. I might later on make another one like yours but instead of the rigged tubing use a more smoother one. Was thinking of placing a heatsink fin from a cpu cooler in the scoop area to cool the air further.

A comment, great feed back everyone we know these motors do not get much power when "blown" but definately everyone agrees it is well known cooler air does affect performance. I live in WA the performance on a cool wet day is very noticeable compared to a hot day in the 90's the air temp is one of the factors. If anyone else has any other mods or set ups they did to get cooler better air please post would love to see.
Click to expand...
i was going to get one of those knock off tornados and place it in the cone...but i just moved on and didnt finish it...the biggest thing when the cone is facing frontward is a good air filtration system...those tornatoes can be picked up on ebay fairly reasonible...when i get home from work i'll send a pick from the front...hope you keep your energy up on this...i always thought it would be a good mod...Dennis
 
Nate D

Nate D

New Member
Jun 25, 2009
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auburn, wa
drhofferber said:
i was going to get one of those knock off tornados and place it in the cone...but i just moved on and didnt finish it...the biggest thing when the cone is facing frontward is a good air filtration system...those tornatoes can be picked up on ebay fairly reasonible...when i get home from work i'll send a pick from the front...hope you keep your energy up on this...i always thought it would be a good mod...Dennis
Click to expand...
I kind of like the current scoop for the fact it is out of the way does your leg ever hit the scoop or tube? I think I'll add a mesh screen on it for now til I get bored with it. I ordered a boost bottle that will be my next mod possibly a race carb down the road. Yes please send pic of the front of the air ram for us to see.

I use my bike as a commuter, to the store, to visit friends, take with me camping and the ocean I get a lot of use out of it so dont want it to be too loud and hopped up Just so I can hit the 35mph mark easy. Mine is a very comfortable set up I have a rear suspension seat by Schwinn and the front has shocks with lock out button for smooth rode riding and of course i have the rear and front fenders. Very nice to ride :)
 
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D

drhofferber

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Jun 22, 2008
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Nate D said:
I kind of like the current scoop for the fact it is out of the way does your leg ever hit the scoop or tube? I think I'll add a mesh screen on it for now til I get bored with it. I ordered a boost bottle that will be my next mod possibly a race carb down the road. Yes please send pic of the front of the air ram for us to see.

I use my bike as a commuter, to the store, to visit friends, take with me camping and the ocean I get a lot of use out of it so dont want it to be too loud and hopped up Just so I can hit the 35mph mark easy. Mine is a very comfortable set up I have a rear suspension seat by Schwinn and the front has shocks with lock out button for smooth rode riding and of course i have the rear and front fenders. Very nice to ride :)
Click to expand...
you have a very nice setup...keep it simple...just remember...if a little rock or bee gets in there it can create havek....our laws in nevada only allow 30 mph...moped law...50cc and under...no m1 license or insurance...if you get caught over thirty they stick it to you...insurance,m1 license...and registration...and a heafty ticket: check your state laws....i used to live on star lake and lake finwick, in your area...nice areas to ride...so check your state laws...enjoy...Dennis
 
2door

2door

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Sep 15, 2008
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Littleton, Colorado
Nate,
I hate to say this and no offence intended but being an old Air Force fighter pilot, your ram air system looks very familiar to me. We called them 'relief tubes' and I'll give you three gusses what we used them for. (Hint: Flight suits have very deep zippers)
Tom
 
Nate D

Nate D

New Member
Jun 25, 2009
40
0
0
auburn, wa
2door said:
Nate,
I hate to say this and no offence intended but being an old Air Force fighter pilot, your ram air system looks very familiar to me. We called them 'relief tubes' and I'll give you three gusses what we used them for. (Hint: Flight suits have very deep zippers)
Tom
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LOL too funny. Well heck if you had one laying around I could have used it. I actually used silicone tubing and a soda bottle though. The only difference I guess is this has 2 tubes instead of one. Well if the airforce considers this a proven design to direct "fluids" then directing air is no prob and simple is good.
Well this is kind of off the subject but I got my "boost" tube installed today they should really call these something else like "air/fuel ratio regulators" or "idle regulators" The description on how these provide a "supercharger" effect had me laughing. It is nothing like a supercharger I read up on its workings well it did not give me any power increase but did lessen motor vibration as it said it would do and does seem to throttle up a bit smoother.
 

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