review of Rock Solid reed valve

[Deleted member 12676]

Just got it in. Here is my technical review:

Design flaw
Sucking on the intake side of it reveals an air leak. Took it apart (3mm allen wrench) to discover the internal gasket covers only half of two 1/16" diameter holes that bypass the reeds. not good. (see drawing)
So all owners need to take it apart and glue those holes shut with something gasoline resistant like JBWeld. (silicone sealant wont work). It will run much better sealed. And trust me, there is no reason to have bypass holes. The reeds need to completely prevent all blowback.

Flow Volume
Looks like the maximum possible flow volume (cross sectional area with both reeds open) should be 111 square millimeters which matches the 113sqr mm of a 12mm carb. But since they didn't angle the valve downward it then hits the upper port surface after only opening 2mm which results in only 84 sqr mm volume.

Performance
This is going on my 55cc engine with 12mm Dellorto carb ported out to 14mm. If I bore the intake to give the upper reed more room to flex then I expect to be able to rev even higher since this ported engine is limited by my homemade reed valve which has stiff reeds and only around 88 sqr mm flow area. But the crankcase on mine is stuffed which makes it favor high rpm power. I am making an expansion chamber for a peak rpm of 9300. See my web site (click on my signature link) for info on how to drill holes in the pistons intake skirt and make a boost port. These are essential steps for use with a reed valve. I expect this valve will give low rpm gains for both 48cc and 66cc engines but will limit revs on the thirsty 66cc engine.

My recommendation to Rock Solid:
Seal those holes to begin with. And design a wider reed valve to be sold with 66cc ported cylinders that allow a wider design. And angle the valve downward. (And make the mounting hole spacing 40.5mm for the 55cc and 66cc engines.)

 

[Fabian]

As far as i am aware of, there is no mixture screw on the NT carburettor, but only an idle speed screw.

There is nothing wrong with the standard carburettor but a Walbro style carburettor commonly used in chainsaws is by far the better option.
I will be purchasing a Walbro carburettor (with adjustable low speed and high speed mixture screws) from Rock Solid Engines as a stop gap measure until their Electronic Fuel Injection kit hits the showroom floor.

 

[Lunardog]

Ok guys heres a quick semi update. Found some micro drillbits in my box and tried to open the jet in my carb. Bad plan...lol. Even as small as I opened it , it was too much. Ordered a set of 5 jets from dax. 60 ,65 ,70 ,75 ,and 80. Put the 80 in and it was drawing too much fuel regardless of clip placement on the needle. Dropped to the 75 and she responded better however I adjusted the float also and went too far as my carb is on a bit of a slant and this allowed the bowl to overflow. During the run even with the float incorrect I did experience a better low end torque on the hills. I have some steep inclines here in Pa. and even the worst on my trips she almost climbed completely without peddaling. The long gentle slopes she pulled at a steadier pace and without having to downshift as much. I have reset the float and verified seal and will test again in the next couple days. There may be a need to get 71 thru 74 jets to tune it perfectly but for now I will play with this one and see what happens. I recently purchased a boat and that has eaten up my bike time for the last month or so...lol. Ill post again when I finish testing this 75 jet. Thanks again for the help and info guys. As always you save me a lot of trial and error testing with your knowledge.

 

[Ivan H]

Hi, I have RSE reeds & have just cut 2 ports in the piston, 2 Jags heights, both r 9mm wide with 6mm left between, removed 5mm from skirt & port floor + boost port. Cut intake ceiling horizontal depth 8mm, width 20.5 to allow upper reed clearance as its needed. Jetting went from 25 pilot 72.5 main to 32.5 pilot 92.5 main & will order 1 richer main to get it spot on. Very good power ncrease right thru. Cheers

 

[Deleted member 12676]

good for you. all you need now is a good expansion chamber.
I was experimenting today with my 55cc cylinder with the same reed valve and got it up to 7830 rpm with very tame porting and just the stock exhaust. Of course I have a Dellorto 14mm carb and a Honda piston, 120psi compression, Jaguar CDI. Like you, I also dremeled away some of the ceiling aluminum at the intake to make more room for the upper reed movement.

 

[Ivan H]

Hi Jag, have SBP plated chamber, but wouldnt mind 1 of ur designs next. Also have SBP shifter/8 speed shimano, RSE head, NTN main/4thou end float, countershaft/10x14x15 small end, 16mm mikuni, RSE pull start & home made CDI along ur lines, on hi strength hand made frame I scored from Op Shop for $60. U do some good development work on these Jag, cheers

 

[BadgerMW]

Recently bought a RSE reed valve kit, installed it once but was too lazy to re-jet carb and possibly boost port the jug.

Let me know if anyone wants it, I paid $80 from JNM looking to get some of it back.

The reed valve is in almost brand new shape, installed it on new engine, rode it to the end of driveway and back and took it off...been sitting in the garage ever since.

Jag's site has some very detailed instructions on setting it up right.
http://www.dragonfly75.com/motorbike/reedvalve.html

 

[Deleted member 12676]

maybe you gave up on it because you saw no improvement. Why don't you drill a couple holes in the piston skirt in order to see some benefit from the reed valve?

 

[BadgerMW]

Ill PM you

 

[Deleted member 12676]

For the benefit of all this was his concern:
"I really like the product but I'm worried about the reliability of the piston and jug in the future. I saw other members that had gone and drilled holes in their pistons and it resulted in small scratches in the cylinder walls. At first I am sure I will see good results but over time i feel it will lower its reliability and life."

I replied:
1st, these engines are too low power to put stress on the piston. I used to run a piston with 27 holes in it. I ran up to 8500rpm no problem, going downhill with throttle full on to see if anything would break. nothing. ran great for a few months till I switched for different testing.
2nd, any idiot can feel that drilled holes leave raised edges that need to be taken off with an exacto knife or something. It was the raised edges that scratched the cylinders.
3rd, you can always slap in a motorcycle piston that has the windows in the intake skirt:
47mm Hoca Minarelli piston and rings for reed valved engines -
http://www.partsforscooters.com/169-188_Piston_Ring_Set
Thinner rings, preserve cylinder coating, less friction for higher RPM's and less blow-by for better compression. 85mm rod motors (Grubee brand/Type A) will need a 5mm spacer (between crankcase and cylinder).

46.8mm Honda Hobbit overbore piston kit for reeded engines $66
https://www.treatland.tv/honda-hobb...nt-piston-p/hobbit-polini-piston-204.0278.htm
Compression height of 25.5mm and overall length of 50mm, it'll need to be trimmed 2mm at the skirt but it should work in the 80mm (dax) rod 66cc engines. Sits 0.5mm higher than stock and will boost compression significantly


The only tricky thing to drilling the holes is that you have to make a mini-ditch for the bit otherwise the drill bit will wonder off center. I used a rotary tool but even a pointy hunting knife can do that.
If anything a reed valve can increase reliability by reducing the vacuum on the crank seals caused by piston port intake as the piston raises. Rvalve only allows crank pressure (and just a little vacuum).

 

[bahramu]

Badger, too bad you didn't also get the Walbro carb with reed valve adapter. The walbro kit + RSE reed-valve kit from JNmotors is on my "dream" list. I'd love to pick up one of those second hand.