Reed Valve Kit

Rocky: Expansion chambers vary in price drastically across the board. Moped pipes can cost anywhere from $50-220 and more expensive isn't 'Better'.

Pipe geometry is what effects Everything, and for his processes and materials, his cost may be higher than SBP's. Furthermore, SBP's pipes seem to have pretty insane header lengths, Arrow's pipes look to be much nicer for mid-to-high RPMs.
I'd have to see the blueprints to be certain, but if it were my $, I'd spend it on the newcomer.
 
Tohri said:
Rocky: Expansion chambers vary in price drastically across the board. Moped pipes can cost anywhere from $50-220 and more expensive isn't 'Better'.

Pipe geometry is what effects Everything, and for his processes and materials, his cost may be higher than SBP's. Furthermore, SBP's pipes seem to have pretty insane header lengths, Arrow's pipes look to be much nicer for mid-to-high RPMs.
I'd have to see the blueprints to be certain, but if it were my $, I'd spend it on the newcomer.
Click to expand...

I see. It would be nice to know what exactly his pipe is tuned for. But I'll probably be buying his exhaust anyway. Looks to snazzy to pass up and I'm sure performs well. Just waitin on thatsdax to get his carburetors in stock agian before I do anything else.
 
Venice Motor Bikes said:
I ordered two of these on Tuesday night & I got them both today! Lightning fast shipping & a quality product! (^)
I even had time to install one & test it a little. ;)

vmbreedvalve2.jpg
Click to expand...

Norm! how'd it work? extremely curious...
 
dave you do the bike world justice love the product and shipped so fast to me way down here in tasmania australia got to be the luckiest bloke down under just tuning and jetting a new look carb but when i do wow i be pulling 77 k easy
 
Last edited:
Here's my first post about how it worked... I should have just bolted it on & tested it without doing any mods; but i didn't... :-{
What I did right out of the gate was to remove the cylinder & cut a wide groove down the inside of the cylinder (from the base of the intake port straight down) to keep the intake manifold open to the crank case 100% of the time.

What I found from doing this was that the engine lost 80% of it low end power, but it gained noticable power from the mid RPMs all the way to full RPMs. It didn't gain any top speed, but now it has a lot more power! With the revs up, it can now climb hills that it couldn't before. (^)

I'm going to experiment more when I get some time.
 
Venice Motor Bikes said:
Here's my first post about how it worked... I should have just bolted it on & tested it without doing any mods; but i didn't... :-{
What I did right out of the gate was to remove the cylinder & cut a wide groove down the inside of the cylinder (from the base of the intake port straight down) to keep the intake manifold open to the crank case 100% of the time.

What I found from doing this was that the engine lost 80% of it low end power, but it gained noticable power from the mid RPMs all the way to full RPMs. It didn't gain any top speed, but now it has a lot more power! With the revs up, it can now climb hills that it couldn't before. (^)

I'm going to experiment more when I get some time.
Click to expand...

To make proper power you should cut a 5th boost port above the intake port. Cutting a port below the intake isn't going to improve power and will actually decrease your crankcase compression ratio which is where your loss in low end power came from. The extra high end power probably came from having 360 degrees of intake port timing because of that new cut you made.

If you cut the new 5th transfer above the intake port you might be able to gain extra low end power by improving scavenging of the combustion chamber at low RPMs. You can also trim the piston skirt to increase your intake port time-area.

Generally for cylinder reeded engines 360 degrees of intake port timing is not always a good thing.
 
i just got mine installed from arrow cycles today:D OMG this thing is AWESOME!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! the bike runs SO and i mean SOOOOO much smoother quieter and more POWERFULL than ever before. Before it sounded like a ticked off weedeater now the engine just sounds like a moped. I could not be happier with this purchase, if you are thinking about getting one just go ahead because you WILL NOT regret it. well one more thing after riding around i found out that i do not have a self oiled air filter anymore, no biggie thats what they make air filter oil for right guys?
 
I tried to look up his expansion chambers today, the link is dead... does he have a new one or... good god don't tell me he's not making anymore pipes.... :(
 
Nice Build Venice, I love the reed valves i got mine from rock Solid in Australia:

Sorry i cant upload image but my signature has it :)
 
Here's another update... I cut that intake port (from the carb) upward to just below the height of the two stock side ports... The bike gained all the low RPM power back & has even more high RPM power. I was only able to ride it a few blocks before I had to close shop today.
Tomorrow I'm adding that much needed front disc brake to the bike & then I'm going to do some GPS testing.
I really think this bike is going to need a 36T rear sprocket soon! (^)
I'll post more later. :)
 
More progress... Today I decided to widen the new upward transfer port & also drill a hole throught the back side of the piston to help the airflow from under the piston to go up the new transfer port.
It gave even more crazy top end power but I lost the bottom end again... :/
I also did this testing without re-jetting the carb, (which it really needs now).
I'm going to try jetting the carb & install a expansion pipe & report back later.

So-far, for top end power, this is working really well. (^)

Here's some pics of what I did...
vmbenginemod2.jpg

vmbenginemod1.jpg
 
​
Hi Dave C, having 2 seals isnt redundant as when the piston starts travelling down, the compressing mixture travels up the transfers & back out the carb til the piston closes the port. Its called "reversion blowback". The reeds stop the reversion blowback. Cheers
 
You must log in or register to reply here.
Back
Top