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GHETTO FABRICATOR
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Discussion Starter #1
Anyone have any info or expeience with the reed stuffers?

Either this application or others?



 

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GHETTO FABRICATOR
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1,114 Posts
Discussion Starter #3
What type of info are you after J? I do not have direct info (I don't have one) But I could tell some stories, and talk about how it works / doesn't work, but I'm betting you have read the same Books as I have! :)

Actually I know little to nothing about them so any info would be an improvement.
 

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But who prays for Satan?
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I'll try to do my best...

lets start with something not good, just to be weird....

Like another user was talking about, they can be thought of to be "in the way" but if we are going to be thinking like that, the reeds are basically in the way too.

the tip of the stuffer is pretty small, and is in fact reducing the amount of possible flow, If we are talking about Flow-Bench numbers, strictly moving air, but, aligning the charge and adding velocity to it should not be overlooked, an example I used earlier is Velocity Stacks, the reeds already have a natural taper to them, so they are in fact "Reducing flow" well, to some extent the stuffer can be thought to do the same thing.

O.K. that is some of the dirty bad stuff, not much except the fact that it is one more thing in the way of the air intake tract.

Now lets talk about some good stuff...

Case volume / displacement, O.K. so Technically they are behind the reeds, as in outside of the case, but what about when the reeds are open, should we not then assume the inside of the reed cage to be counted as case volume? it is a tricky question, but when the reeds are open, I think yes! :)

Why would we want to reduce case volume? to increase case pressure, there is a thing called a "VG" turbo, variable geometry, in this setup the turbo housing actually changes it's internal size, using baffles, as the turbo housing moves in on the compressor the PSI's go up, The Volume does go down a bit, but sometimes Volume is not everything, Low end power!

The stuffer, leaves less "open" space for the mix to "mess around" in, it helps align the flow to a nice straight and tapering path, think of the tapers as being there to add velocity, like on a hose with a nozzle?!!!

Believe it or not, once the Mix has been atomized by the carburetor, unless we do something to mess it up (Smooth Surfaces, Sharp Angles etc) it can be thought of as good to go! the more chances we give the mix to puddle, or pool, or even just circulate the less atomized it will "most likely" end up being, Now please do not get me wrong, circulating the "mix" around the case is important, we are talking about a 2-stroke, without oil injection, with ummm bearings! but when speaking of performance, The fuel would love to come out of the carburetor and Explode right away :eek:

I believe, there would be slight pumping losses, but I think there should be a larger gain to be had from the Velocity / pressure differences "Bernoulli's principles" and the "Aiming" going on...

I do believe in Velocity Stacks etc, when they are designed right as well as Crank Stuffers! and yes, I like the idea of Reed Stuffers, but I really am BROKE!!! :eek:

I hope some of this (I guess you could call it) Information is correct / useful, as always, I am an AZZ, and this is no doubt my "Crazy" interpretation of what is happening, based on examples I have been shown, articles I have read, and other peoples brains I have picked! I admit RIGHT NOW, I could Easily be wrong, and will not be too sad if anyones opinion's differ, this is the Internet, and I could be a 10 year old kid Quoting Google, but, copy/paste some of the stuff I write, you should be able to Verify, I copy/paste by reading everything in sight, adding my own twist on it, and writing back on here off the top of my head, I think I'm a tiny bit smarter than "normal" and am willing to be proven wrong, if it means I got to Speak what was on MY mind.

I hope some others will join in on this too, it is a really cool subject! and has been up for "Debate" for years. So have reeds for that matter, ever read about piston port pared with "Case Reed" ?!?!? yummy! I'll link you to the standard two stroke tuning books I got the vast majority of my info / perceptions from if you like, it makes for some good bedtime reading! :eek:
 

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But who prays for Satan?
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I talked to PBU before about the spacers used between the reed cage and the cases in B1 & C1 Blata Rep bikes. There's are .200" thick and they said go no more than .250" at the max.
My C1 already has 4 CF reeds on a 46cc B/B engine, thats not enough, I just want to add the spacer, which I believe moves your reeds back so they can open wider.
 

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But who prays for Satan?
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I talked to PBU before about the spacers used between the reed cage and the cases in B1 & C1 Blata Rep bikes. There's are .200" thick and they said go no more than .250" at the max.
My C1 already has 4 CF reeds on a 46cc B/B engine, thats not enough, I just want to add the spacer, which I believe moves your reeds back so they can open wider.
The Stuffer is for "Inside" the reed block, you could do a spacer too, but it would be better to just mod the case, (engine case) spacing the reeds back adds slightly more case volume than just opening the section of the intake where the reeds are being blocked from lifting, Lower case volume and pressure is REALLY important to avoid! <--usually!

But I would say, for the newer guys that hate to grind stuff down, A spacer is an easy part to make / add, and it does show overall gains. :cool: :thumbsup:
 

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Two Stroke Addiction
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The stuffers are "designed" to minimize turbulence and redirect flow to properly distribute the intake charge across the reed petal surface...but...let me tell you this: Unless Your VE (Volumetric Eficiency) is at least 80%, the turbulence inside the engine really doesn't matter....I mean, there are A LOT of other factors to take care of to gain performance.

I have played around with stuffers and no stuffers for long time....and I don't "feel" any difference, I bet there is a difference if you test your bike on a Dyno, but for most of the people not having acces to a Dyno, using the stuffers or not, is the same...just my 2 cents.

Regards,
 

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But who prays for Satan?
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Thanks for the input Mexicano, Like I said, I have no direct connection to reed stuffers, I have only read about them, and thought about them, I bet you have tried more than a few "Other" tricks too, on the Scooters?

I Bet J and the rest of the guys would LOVE to hear some of your other thoughts, And I know I would! :) :thumbsup:

For instance, have you "Played" with Crank shaft Stuffers too? and did you like them? or was it about the same as the reed stuffers for you?
 

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GHETTO FABRICATOR
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Discussion Starter #10
Thanks all for the imput.

Was actually thinking of doing the reed spacer along with the stuffer.

For the time being I think I will hold off on both.
 

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Two Stroke Addiction
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654 Posts
Thanks for the input Mexicano, Like I said, I have no direct connection to reed stuffers, I have only read about them, and thought about them, I bet you have tried more than a few "Other" tricks too, on the Scooters??

I Bet J and the rest of the guys would LOVE to hear some of your other thoughts, And I know I would! :) :thumbsup:

For instance, have you "Played" with Crank shaft Stuffers too? and did you like them? or was it about the same as the reed stuffers for you?
You're wellcomed, Nick

I have been doing racing scooter engines since 2003, lots of trial & error for my learning process, lots of reading, but the most important is to TRY new things, there are LOTS of racing parts for scooters, there is too many RD made by others, the sky is the limit(and the money, of course), not sure if all the "tricks" can be used on this small engines, I guess most of them, It's a matter of try them and see what happends, I will be glad to share with all of You what I have learned thru these years.

The cranks I use for my scooters have stuffers from factory, I have never used other type, the stock cranks are not full circle/no stuffers but never had used a stock scooter engine for more than a couple of weeks.....need for speed;LOL

This is the last crankshaft I got from Japan, it is to built a new 103 c.c. engine...some time in the future when I have plenty of time, I'm runing now a 110 c.c.

The crankshaft:



Jaloos: As for the reed valve: forget about the stuffers and the spacers, grind the carter to allow for more petals opening and If you really want a reed valve that works best, go for the VForce...or a Malossi VL14, the VL14 is good but not as good as the VF...once I put my hands on the C1 engine I will develop my own VF reed, stay tuned!
 
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