Jump to content

RAD VALVES


Recommended Posts

I bought a used shee with rad valves I also have VF-2 that needs new reeds. Would I be better off to change reeds. The bike has fmf fatty pipes,coolhead 18cc domes,stock porting,28mm flatslide carbs,open lid on airbox and 20 over fresh bore. :notworthy:

Link to comment
Share on other sites

I like the V Force 2 reeds better then the rad valve. i tried the rad valve and i really didn't care for them, then i put in a set of the V force 2 reed valves and it really made a big difference in the throttle response. i ended up selling the rad valves

Edited by TREELIZARD
Link to comment
Share on other sites

banshee reeds/intakes are already straight , theres no angle like on a dirtbike. im pretty sure dirtbike type inlets are where rad vbalves really shine, to help the flow make that turn into the case area. on a banshee the air has a straight shot from the filter through the carb and into the reed cage, so a rad valve wouldnt actually help anything.

Link to comment
Share on other sites

If you decide to go with the V Force2 reeds then you are going to have to modify your stock intake where it bolts up to the cylinder. there is a rubber piece that fits inside of the stock reed cage that will need to be cut off when you use the V Force 2 reeds

Link to comment
Share on other sites

i currently run the rad valve reeds but the cages have been ported and i love them so if you don't mind doing a little work on them then i would keep them. just my .02. if you would like to see some pics of mine i can send them to you to get a idea.

Link to comment
Share on other sites

banshee reeds/intakes are already straight , theres no angle like on a dirtbike. im pretty sure dirtbike type inlets are where rad vbalves really shine, to help the flow make that turn into the case area. on a banshee the air has a straight shot from the filter through the carb and into the reed cage, so a rad valve wouldnt actually help anything.

Yep. The rad valves do great on engines where the reed valves are at an angle.

 

I haven't seen a single engine builder yet that recommends rad valves over v-force. Look at a v-force design, and you can't beat it. If all the reeds open up the same angle as a boyeson cage, then the v-force will flow more. The only way for another cage to flow more than v-force, is for the reeds to open further, which will shorten life expectancy.

Link to comment
Share on other sites

Yep. The rad valves do great on engines where the reed valves are at an angle.

 

I haven't seen a single engine builder yet that recommends rad valves over v-force. Look at a v-force design, and you can't beat it. If all the reeds open up the same angle as a boyeson cage, then the v-force will flow more. The only way for another cage to flow more than v-force, is for the reeds to open further, which will shorten life expectancy.

 

I take it that you're the same type of person that swears that your boost bottle adds a ton of low end power. :baseball_innocent:

Link to comment
Share on other sites

I take it that you're the same type of person that swears that your boost bottle adds a ton of low end power. :baseball_innocent:

No, I just happen to be majoring in mathematics/computer science and minoring in physics. The v-force design is better, plain and simple. You can't make the valve any wider. So the only way is to get the valves to open further. You keep a stock like design (RAD), and you have to open the reeds further to flow more. Bending the reeds will fatigue them quicker. Not to mention it won't have as good of control at high rpm. The v-force can achieve the same flow while only opening half as much.

Edited by dawarriorman
Link to comment
Share on other sites

No, I just happen to be majoring in mathematics/computer science and minoring in physics. The v-force design is better, plain and simple. You can't make the valve any wider. So the only way is to get the valves to open further. You keep a stock like design (RAD), and you have to open the reeds further to flow more. Bending the reeds will fatigue them quicker. Not to mention it won't have as good of control at high rpm. The v-force can achieve the same flow while only opening half as much.

 

If you want to stack your proposed degrees against mine, let's go at it. I have a BS in Vehicle Design and an MS in Mecahnical Engineering. I work for one of the world's premier racing organizations as a PMME.

 

You have missed theone of the key points of intake system designe completely. The goal is to stuff the maximum amount of air that you can down in the the engine. This is not necessarly done by trying to make the largest opening possible (you may want to re-think your choice of minoring in physics). In any intake system, laminair flow through the tract is the key, but the air has to be below super-sonic speeds. Past super sonic speed, the air stalls and and begins to decrease flow throgh the system at an exponential rate. Needless to say, if the flow is not laminair, the flow through the system will stall at a much lower speed. As not to write a book on the subject, the priniciple used in the development of such systems is call "reasonant ram tuning".

 

Additionally, I have been to both the Boyesen and Moto Tassarini facilities, Boyesen does development on their products including CFD trials. Moto Tassarini has some spread sheets and a flow bench that is older than I am. Aside from everyting else, ask yourself, who's reed system do you want in your bike?

 

My entire arguement falls apart if you wind up with a 35mm carb or larger. That is the largest venturi system that the XL RAD Valves are designed for. If you're going bigger than that you need to be looking at some cylinder that accept 250cc dirt bike reeds and cages.

 

Thank you, drive through. :baseball_santa:

Edited by FireHead
Link to comment
Share on other sites

damnit :clap::headbang:

 

Sorry about that, I was having a rough day at work when I posted that. It's the truth though. I tend to have a problem when folks claim to be right by flaunting their degrees, or soon to be had degrees in this case. :baseball_innocent:

 

All that really matters is that you are happy with what you have and your bike runs properly. If your bike doesn't make 100hp or more, the type of reeds you have doesn't matter as long as they are a quality aftermarket set. :baseball_santa:

Edited by FireHead
Link to comment
Share on other sites

Sorry about that, I was having a rough day at work when I posted that. It's the truth though. I tend to have a problem when folks claim to be right by flaunting their degrees, or soon to be had degrees in this case. :baseball_innocent:

 

All that really matters is that you are happy with what you have and you bike runs properly. If your bike doesn't make 100hp or more the type of reeds you have doesn't matter as long as they are a quality aftermarket set. :baseball_santa:

i agree! :thumb:

Link to comment
Share on other sites

Sorry about that, I was having a rough day at work when I posted that. It's the truth though. I tend to have a problem when folks claim to be right by flaunting their degrees, or soon to be had degrees in this case. :baseball_innocent:

 

All that really matters is that you are happy with what you have and your bike runs properly. If your bike doesn't make 100hp or more, the type of reeds you have doesn't matter as long as they are a quality aftermarket set. :baseball_santa:

Ok then, at least you know what you're talking about. I tend to take it personal when people call me stupid, and then have nothing to back it up with.

 

But you still haven't showed me how the RAD valve is better. A flow bench is a great tool, but it can't simulate the air flow in a 2 stroke engine. If thats all moto tassinari has, then that does make them seem a little backwoods, but you don't always need fancy equipment. All you did is explain what happens to supersonic air through the intake. (By the way, you ever read mototuneusa guy's reduction porting, how he blew off the guy that told him he was full of it?). I still have never seen someone who ports these engines recomend the RAD valves.

Link to comment
Share on other sites

Ok then, at least you know what you're talking about. I tend to take it personal when people call me stupid, and then have nothing to back it up with.

 

But you still haven't showed me how the RAD valve is better. A flow bench is a great tool, but it can't simulate the air flow in a 2 stroke engine. If thats all moto tassinari has, then that does make them seem a little backwoods, but you don't always need fancy equipment. All you did is explain what happens to supersonic air through the intake. (By the way, you ever read mototuneusa guy's reduction porting, how he blew off the guy that told him he was full of it?). I still have never seen someone who ports these engines recomend the RAD valves.

 

Moto Tassinari is a company that is full of the Italian and German equivalent of Arkansa hillbillys. From my experience, CFD systems are the best experimental tool for evaluating two stroke intake system designs.

 

I have not seen mototuneusa's reduction porting. Post up a link.

 

One thing that I do know, is that no one in the industry know's everything about anything. I am not sure RAD valves are not reccomended like the V Forces are. For the last 5 years I have alwasy done my own porting on a CNC mill. I don't know anyone outside of the top tier manufacturers that do porting in this fashion, therefore I never pay much attention to what other porters reccomend. :baseball_w00t:

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...