Air scoop

jus_me said:
When i get home on Monday I'll post pics. I know it's internal heat that kills motors. Hence why diesels last allot longer but if I'm wot for miles id like the xtra cooling a scoop does, i can't see in any way scoops affecting running temp at slow speeds. Plus i got a nice spot for stickers. Some how we got off subject . Any how scoop looks good 79 bronco. You do "clean work" ...
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If your are WOT for miles then there will be ample air passing over the fins to keep the motor at the correct operating temperature.

Have you considered what turbulence you may be creating by putting restrictions in the air flow.

I understand very little about aerodynamics, but I do understand that if you increase the distance that air has to travel across a surface to get to the same point on the other side of the restriction, you create an area of low pressure.

If I have confused you, study the dynamics of an aircraft wing, lift is produced by the lower air pressure on the wings upper surface..

There may actually be less air passing over the motor with a funnel in the way, or am I barking up the wrong tree.?

Contrary to public belief stickers do not add speed, they add extra weight and drag.
 
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After 20min of hard riding on a air cooled blaster you can have anywhere from a 15% to 20% HP drop from HEAT. A liquid cooled motor kit has a advantage because more constant temp that helps keep the hp from dropping as much.

If a scoop helps keep the motor running cooler on a air cooled motor then it has to help!
 
79 bronco said:
After 20min of hard riding on a air cooled blaster you can have anywhere from a 15% to 20% HP drop from HEAT.
Click to expand...

If the above is correct it would be a sign of incorrect jetting or a related problem.

If air scoops actually do work.

Air scoops on an air cooled motor would not be needed unless the motor is veiled behind a fairing or similar air restricting structure..

If an air cooled motor in open space is running hotter than optimum then jetting must be incorrect!

Increasing the main jet size will return a cooler running motor and surprisingly could produce more power.

In cooler weather do you remove your air scoops or do you adjust your jetting.

Air scoops are pleasing to the eye but should not be used as a substitute to proper tuning practices.
 
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79 bronco said:
After 20min of hard riding on a air cooled blaster you can have anywhere from a 15% to 20% HP drop from HEAT. A liquid cooled motor kit has a advantage because more constant temp that helps keep the hp from dropping as much.

If a scoop helps keep the motor running cooler on a air cooled motor then it has to help!
Click to expand...

Blaaster said:
If the above is correct it would be a sign of incorrect jetting or a related problem.

If air scoops actually do work.

Air scoops on an air cooled motor would not be needed unless the motor is veiled behind a fairing or similar air restricting structure..

If an air cooled motor in open space is running hotter than optimum then jetting must be incorrect!

Increasing the main jet size will return a cooler running motor and surprisingly could produce more power.

In cooler weather do you remove your air scoops or do you adjust your jetting.

Air scoops are pleasing to the eye but should not be used as a substitute to proper tuning practices.
Click to expand...


FACT!!!!! After 20min of hard riding on a stock 2 stroke air cooled motor that is jetted correctly you can have anywhere from a 15% to 20% HP drop from HEAT, and A stock 2 stroke liquid cooled motor has a advantage because of its more constant temp that helps keep the hp from dropping as much.

My motor runs the best right after it gets warmed up, and it get a hell of a lot hotter then that after some hard riding. Id like to ride all day just above the warmed up temp, and be pleasing to the eyes.

When we start adding stuff to our blaster like different hoods, bumpers, shocks with remote reservoir and steering stabilizers we may be blocking air from our motor. So if adding this stuff may block the air then we can hope adding a scoop may add some air back.

I cant see a scoop screwing with the jetting, but that is a interesting idea, i may have to find that out.
 
Adding an obstruction that simulates an air foil in the orientation that most people do will slow down the airflow.

Add two and the resulting air flow would be very much restricted, or is my understanding of wing dynamics lacking.

Faster air flow could be achieved by using a device shaped like a V, placed directly in front of the cylinder to speed up the air.

Food for thought Eh!
 
Blaaster said:
You make the claim, you Google to fame, and I will eat my words.
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Its not worth the wast of my time to google it for you just because your a lazy unbeliever to google it your self.

I dont know about you but in most bikes i ride i can notes the difference in power when the bike is cooled, warmed up and hot from hard riding.

Im talking about HOT from hard riding!!!! NO OVER HEATED!!!!!
 
So for the heck of it lets say the scoops aren't doing anything but providing cooler air under your seat. Because we all know heat rises and a two stroke motor can get pretty dang hot. Now is there an issue about cooler air under your seat? For most of us your dang right there is. That's where are carb sucks the air from. And i would gladly post thousands of articles about the cooler the air you get into your engine the more efficient and powerful your engine will run.
I highly doubt we could ever cool this engine down enough to not make it run properly. Theres the dt and wr 200 that are liquid cooled blaster motors. I don't see them running to cool. So why didn't they just make them air cooled? It would have saved yamaha a boat load of money on cylinders, radiators,water pumps, and so on. why we ask? because there bikes and go down the road and need the xtra cooling.
 

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I found this little nugget when I was following 89's lmgtfy: "savvy tuners over jetted,_ using the extra fuel's heat of evaporation as an internal engine coolant, and to limit combustion flame temperature. Jetting to the chemically correct mixture (at which every molecule of oxygen in the air charge i1-reacted with hydrogen or carbon from the fuel, leaving no extra fuel unburned) gives maximum power and maximum heat release, hut on that jetting, poorly cooled engines would run hard for a couple of laps, then cook. That heat would cause the intake air to expand and lose density, thereby causing power to fall off. Over jetting, by limiting this heat, allowed engines to lose less power. This is why. even today, air-cooled 500 MX engines sound so rough; they are over jetted to the point of misfiring when cold-so they'll keep more of their power when they're hot. More cooling would help these engines."
Is it just a coincidence that the guy who likes to run his bike rich doesn't think it needs more cooling?
 
Here is the link: Ten bike myths

Verdict: cooling scoops are flippin' sweet
2zs5lq1.jpg
 
Blaaster said:
You make the claim, you Google to fame, and I will eat my words.
Click to expand...

79 bronco said:
Its not worth the wast of my time to google it for you just because your a lazy unbeliever to google it your self.

I dont know about you but in most bikes i ride i can notes the difference in power when the bike is cooled, warmed up and hot from hard riding.

Im talking about HOT from hard riding!!!! NO OVER HEATED!!!!!
Click to expand...

Blaaster said:
I will take that as a no, as you cannot back up your claim.
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Haha You cant Google me WRONG!!! And now you want me to Google myself right. Im not wasting my time because you know it going to be hard to find the info, and you gave up on Google me WRONG!!!

I dont know about you but i dont believe everything i find on the Internet.

BUT i do believe the dozen or so old timers that i know that raced or had kids that raced air cooled 80cc and 125cc bikes in the past and they will tell you something like that the old air cooled 80cc bikes ran great for the first four laps until power fade from heat and that the Liquid cooled motors were a big improvement.

I also know i few people that are in to riding vintage air cooled trials bikes, and some can tell you that there bikes run strong for the first 2 loops then they will take a 20min brake before they do the last loop because of HEAT!

AND DONT tell me there bikes are not jetted correctly because some of these people are not dumb.

I had a article in a old ATV magazine comparing the old air cooled atc 250R motor VS the Liquid cooled atc 250R motor and it was a very good article, BUT i cant find it. I looked for it a few times in the past so i could post it on here, and had no luck on finding it. And the last thing i want to do right now is spend the next 5 hrs digging for a old magazine AGAIN so i can send it to you to EAT! lol

In the past I also posted a article on here from a old ATV magazine on a blaster with a Liquid cooled head, and it also talks about power loss from heat on a air cooed motor.

I dont know about you but i dont believe everything i read in a magazine!
BUT i do believe in my ass dyno!
 
Here is a discussion on air cooled 2 strokes and these people know about the loss of power from heat! >>>> air cooled 2 stroke in new frame/suspension? - General Dirt Bike Discussion - ThumperTalk

But i dont believe everything i find on the Internet.

And i do believe my ass dyno and the old timers i get my info from, so id say the people on that site may know what they are talking about.

What i found very interesting on that post is the talk about a air-cooled 1986-1988 Kawasaki KDX-200 and it had some kind of powervalve!!! Is this true??? I was looking for pics and i found a 1984 Kawasaki KDX200 cylinder and it has a huge intake and the rear cylinder studs go up through the cylinder like the CT240 cylinder. LOOK>> 1984 Kawasaki KDX200 Cylinder Core Needs Repair 66 mm Chrome Bore 84 KDX 200 | eBay
 
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