Team GPR

[mr bucketracer]

will try some reeds with more tension, i know years ago the one i made with more tension made more hp but lost midrange (so the set off my pants told me ) lol so a bit of a weigh off

[mr bucketracer]

Will post some dyno runs tomorrow. The reed idea gave no more rpm and less hp but retard gave more rpm . All less hp

[Bert]

that is a good point .as a rs it revs to 14 max .think rs reeds go in it .forgot to try

you can't use RS125 reed block or petals. But test away, would love to see the result

Didn't you guys lot have homemade reeds and blocks for Regans RS that performed better than the HRC kit??? Back in the day of course.

Kel, rule 16.2 or appendix a fails to cover the use of RS125 reeds (they are neither motorS, transmission parts). In fact the new wording sucks even more than the previous lot...

Will post some dyno runs tomorrow. The reed idea gave no more rpm and less hp but retard gave more rpm . All less hp

Hummm interesting result, so I conclude that the restriction in the transfers (and small size) is the source of the problem.
Ok my reason, if by retarding the ignition allowed for more RPM then the flame front must be expanding too quickly acting as a barrier to increasing RPM.
Retarding the ignition effectively slows the timing of the flame front thus allowing for increased RPM.
So given that at high RPM only the charge (air & fuel mix) stored in the transfers is displaced (and sucked) into the cylinder - if one increase the available volume (of the stored charge) then more would provided and the slower the flame front will be.
Therefore, the standard ignition would be more suitable....
My view (two cents)...

[mr bucketracer]

Didn't you guys lot have homemade reeds and blocks for Regans RS that performed better than the HRC kit??? Back in the day of course.

Kel, rule 16.2 or appendix a fails to cover the use of RS125 reeds (they are neither motorS, transmission parts). In fact the new wording sucks even more than the previous lot...




Hummm interesting result, so I conclude that the restriction in the transfers (and small size) is the source of the problem.
Ok my reason, if by retarding the ignition allowed for more RPM then the frame front must be expanding too quickly acting as a barrier to increasing RPM.
Retarding the ignition effectively slows the timing of the frame front thus allowing for increased RPM.
So given that at high RPM only the charge (air & fuel mix) stored in the transfers is displaced (and sucked) into the cylinder - if one increase the available volume (of the stored charge) then more would provided and the slower the frame front will be.
Therefore, the standard ignition would be more suitable....
My view (two cents)...

its makes a ring sound when it hits max rpm. Reved 1500 more but all fall of with retard

[Bert]

its makes a ring sound when it hits max rpm. Reved 1500 more but all fall of with retard

Power falls off everywhere with retarded ignition, but revs higher.

Yip, so with standard timing it works ok up until high revs.
This would suggest that up to a point you are getting enough charge (air/fuel) and everything is working fine (as a complete system).
but if you are only supplying a fraction of required "charge" (air&fuel) to the cylinder at high revs - then power will fall off burning too fast and expanding too quick). Current ignition timing you are hitting a wall (being the speed of the expanding charge at high RPM).
In my mind anyway...
My thoughts about ignition curves and the retarding of the curve shape is that it is a response to the total available charge and timing of the flame front in relation to the position of the piston in its stroke.

Too late and the expansion of the flame front in the cylinder fails to add any increase into accelerating the piston/crank.
Too early, the frame front acts as a barrier thus slowing the piston..
Just right, then the expanding flame front and charge will push/accelerate the piston, thus producing power.

It's a balance of electrics and charge. My theory is that you are not getting enough charge into the cylinder at high RPM.
Knowing the size of the transfers - I think this is the source of the problem....

Note, I'm using the term flame front loosely (expanding gas, explosive energy blablabla)...

The ringing is an interesting by-product of this me thinks....
I did say two cent worth...

I would love to see the transfers opened up another 25-50% of the available spare space. I bet you will see an improvement. If not then you can laugh at me even more than you currently do

[mr bucketracer]

This is rs reed v kr

[seymour14]

This is rs reed v kr

Did Regan ever blend (or chamfer) those intake ports at the base? I think that is an obvious thing to do next...

Was also wondering which of the two exhaust port stubs you mounted in the end. The blended/tapered one or the 'snub nose' one. Was hoping sometime to do a direct comparison of the two and see the results, intention then to make one that brings the most desirable result. I suspect a compromise on the two.

[FastFred]

This is rs reed v kr

Very interesting but which trace is the RS reed?

[mr bucketracer]

Did Regan ever blend (or chamfer) those intake ports at the base? I think that is an obvious thing to do next...

Was also wondering which of the two exhaust port stubs you mounted in the end. The blended/tapered one or the 'snub nose' one. Was hoping sometime to do a direct comparison of the two and see the results, intention then to make one that brings the most desirable result. I suspect a compromise on the two.

exhaust port stubs would be good to try the other

[mr bucketracer]

Very interesting but which trace is the RS reed?

the green , we should try it again and rejet , got a oxgen sencer for the dyno now so should hook it up some time

[TALLIS]

Gees this thread is getting technical.... remember boys, round two is this weekend. Don't push it too hard or Regan will be on the old smoke machine.... I know he would love that

[husaberg]

This is rs reed v

Robinson reeds mods tension etc

Bear in mind, (as far as i am aware) a CR125 VF3 Reed valve is worth a HP on a RS125.

[seymour14]

Gees this thread is getting technical.... remember boys, round two is this weekend. Don't push it too hard or Regan will be on the old smoke machine.... I know he would love that

I think it will probably venture out at this stage as it stands (weather playing its part would be appreciated too).

Making a little spacer this morning, it may be the final nail in the coffin to pushing this over the "impossible" barrier.

[mr bucketracer]

AF metre . Works realy well

[Bert]

AF metre . Works realy well

Apparently 14.7 isn't the magic number for peak power.. 12.6
Need to redraw the wall graph.


For install, this is worthy of reading
http://wbo2.com/lsu/LsuInstal.pdf