Reed valve with extended intake

[Deleted member 12676]

Crazy test #1003: add a reed valve to a piston port engine with extended intake (7.5" total)
Results: idled stronger with slightly better power taking off from a stop. 4% less top speed. no other power difference.

Crazy test #1004: put holes in the piston skirt so that now it is an extended intake added to a reed valve setup
Results: bad off idle power, 20% more top speed (+5.3mph)

Crazy test #1005: remove extended intake
Results: good power throughout rpm, gained .3mph top speed

 

[Deleted member 12676]

Also, if I had to choose between a reed valve and an extended intake for down low power, I would choose the extended intake. It has proven better in my tests.
With the 60cc cylinder I am experimenting with I am very happy with how it runs w/o a reed valve or an expansion chamber. For most people it is as much as you need. I just like the fun of having extra mid range power with the torque pipe in place of the standard exhaust which is why I use it. But if I moved back to a hilly city I would probably prefer just using an extended intake. Probably the best mod there is for almost zero expense. In the picture above it is the sidestepping intake manifold from JNMotors that I used with a 2.5" length of automotive hose. It allows less carb movement than just using hose attached to the stock manifold.
The 60cc cylinder is slightly ported. Most important is having increased the intake port duration to 120 degrees. See my page about upgrading from 48cc to 60cc for porting details.

 

[geebt48cc]

Jag, I notice that you've got pictured the RS reed with extention. So, do you think that this would work close to same with the Arrow reed staying at the 7.5 total length?

 

[Deleted member 12676]

I would definitely try it.
Try different lengths also. My 7.5" was without the distance of the reed valve. (The intake port is 1.1" long.)
You should try it w/o the piston skirt "holed" and then put holes in it to see which way you like best.

 

[geebt48cc]

Well, I plan on doing that if the reed valve ever gets here?? Jag, I just really wonder if the Arrow reed will at least be as good as just using the extention has?.

Hope that with using them both at a total length of 8.5", ..................

(even though piston hasn't been ported for intake) it will hold its own.

Uno, one would think for the 95.00 dollars, that there would be at least a small improvement............

 

[lazylightning@mail.r]

Crazy test #1003: add a reed valve to a piston port engine with extended intake (7.5" total)
Results: idled stronger with slightly better power taking off from a stop. 4% less top speed. no other power difference.

Crazy test #1004: put holes in the piston skirt so that now it is an extended intake added to a reed valve setup
Results: bad off idle power, 20% more top speed (+5.3mph)

Crazy test #1005: remove extended intake
Results: good power throughout rpm, gained .3mph top speed
View attachment 46707

Hi Jaguar!

I remember you writing once about the great synergetic effect of the pipe plus the reed valve and drilled piston. The test you made with the ported piston yielded lower torque now. Was that after changing to a 36 tooth rear sprocket?

Would you say the plain ported piston setup with the pipe is better, than the pipe - plus reed valve and drilled piston? Or is the plain piston + reed valve and pipe better than just a plain piston plus pipe with no reed valve? I guess this means low end torque of course. And what about that super sweet middle to upper end where it wanted to do a wheelie? Then it may be a matter of choosing between the two? Low end or cruising power plus...
I already have a 7.5 inch rubber hose extention from piston to venturi....due to frame - carb fitting problems =-)

Best Regards,
Paul

 

[Deleted member 12676]

What I have written about here does not include use of an expansion chamber. Adding my torque pipe to any of these combinations will of course improve torque.

 

[lazylightning@mail.r]

What I have written about here does not include use of an expansion chamber. Adding my torque pipe to any of these combinations will of course improve torque.

So the pipe with the reed and drilled piston with boost ports is the best for low rpm torque from idle and for middle to upper power rush as well. Yes?

 

[Deleted member 12676]

Yes but unless the engine is 100% optimized you can't expect any kind of rush. But the pipe in this context is my torque pipe, not the other pipes offered for sale.

 

[seb1008]

Would the weber carb work with the extended intake? I am going to buy the stage 3 kit from JNM and I was going to get the Arrow reed valve for it, unless you think the extended would work better.
I am looking for low end power for using in the mountains on gravel roads. Elevation 300-3,000 meters but mostly in the 300 range. Towing a bike trailer. Motor is a 80/66cc with a jackshaft.
Arrow Torquer 2 expansion exhaust.