Fixing the 130R

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roland2001
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Fixing the 130R

Post by roland2001 » Sat Sep 22, 2018 6:26 pm

Gluefixes.jpg
Without going into allot of theory these are the charges I recommend:
1) Diameters of the "intake" tubes: starting with the second tube/intake: increase the INSIDE diameter to 3.5625" (3 and 9/16".)
Decrease the minimum diameter INSIDE to 4.09375" (4 and 3/32"). or 4.0625" (4 and 1/16".) The diameter of the first-stage tube should be increased INSIDE to 1.78125" or(1 and 25/32".)

2) Length(s) of the 3rd stage intake tube:....this depends on how you are measuring the max diameter(s) of the paraboloid cone, straight section and convergent cone; if you are using .040" thick SS and you measure the inside diameter as nine inches (9"), then your overall combustion volume (excluding the tailpipe) will = approx. 1320 cubic inches. If you measure the outside diameter as nine inches (9'), then your combustion volume is reduced to approx.1300 cubic inches. For purposes of making recommendations for the length of the diffuser I will assume a CC ID of 8.92" and be making suggested measurements from the inside of the far wall of the CC.

a) the throat/minimum diameter point of the 3rd stage should measure (be at) 14.5625" from the inside of the far wall of the CC.
b) the lip of the flare of the third stage should measure (be at) 15.1875" from the inside of the far wall far wall of the CC.
c) the bottom of the second stage should extend .3125" (5/16') into the 3rd stage flare, and equal distance of 5/16" from the minimum diameter- measuring 14.875" from the far inside wall of the CC.

3) Length of the 1st stage tube: if both the fist and second stage had the same diameter it would be easy to suggest a length: (the 1st stage would be exactly 1/2 the length of the 2nd stage or 7.4373" long, and extending into the second stage by 1/4 of it's length or =/- 1.859375 inches .......
(I'd round to 1.85".) I tuned my 1st stage to about twice the frequency of the 2nd stage by using an air nozzle, a pitch pipe and my ear, but a oscilloscope would be best. Adjusting the frequency of the 1st stage ( to that of the 2nd stage) should only be performed after it has been flared to spec. The flared second stage is the FUNDAMENTAL to which the first must be compared. Eg. 2nd stage = 440 Hz, then the first stage has to be
880 Hz.

Finally, My experiments have indicated that the 130R is way too rich fuel/air. Metering jets and the hot nozzle have to be smaller (and you will get much hotter sonic flow.) .2125" for the hot nozzle with straight section 2.125" L , and for each of the metering jet I'd go with .070-.071" D. You might have to go to meteric drill bits for these. mail kylebear2000@hotmail.com or call 208 426 8858 if you have questions,
roland2001 aka Kevin

PLease see image attached....this can be confusing.

roland2001
Posts: 18
Joined: Wed Mar 10, 2010 2:24 am
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Re: Fixing the 130R

Post by roland2001 » Wed Sep 26, 2018 3:03 am

re the theory about the changes to the intake:

1) first, re the lengths....the fundamental wave created by the 2nd stage intake tube (the longest) is reflected back from the far wall of the combustion chamber "CC" and is the inverse (opposite) of the incoming wave. This situation sets up the appropriated circumstances for "destructive interference", and thus for all intense and purposes illuminates the reflected 2nd stage wave off of the far wall of the CC.
One might ask "why not just shorten the length of the 2nd stage tube instead of lengthening the 3rd diffuser stage"? The answer has to due with the geometry of the cone, straight section of the CC and the convergent section: Looking at the long or "sagittal" view of the aforementioned you can see that from where the cone joins the CC to where the narrowest part of the convergent reducer cone meets up with the TP measures 14.87". and that the 005" of the 14. 875" lies at the union of the of the CC and the tailpipe. Instead of nodes and antinodes related to the incoming fundamental wave, one migth consider that there is a pumping action the occurs with the pulsations inherent in designs with straight tailpipes and the variations of delagration of the air/fuel mixture that occur. *One important thing bares mentioning: the 1.87" convergent section between the CC and tailpipe also acts as an oscillator and is integral in the aforementioned "pumping action" (pulsations of the engine in the engine).*

2) The 130R is notorious for regurgitation or reflux (what ever you what to call it), at the 2nd and third stage(s) conjunction/union. More than because of the relected wave not being illiminated, the cause of this has to do with the areas of the stages: Going back to Gene's patent he states "the the area of the 2nd stage intake should be no less that 75% that of the 3rd stage". Or words similar to that. The RQ plans misses this mark by a significant amount and the combustion pulsations that occur in the third stage overwhelm the incoming flow of the second stage, where the inverse is supposed to be the case. The changes of/in diameter(s) of the inflow stages (see image above [first post]) have served me very well, and I recommend them highly. The third stage is very much a to-fro balancer for the engine although the compressions are greater than the rarefactions always keeping combustion reflux at bay.

More to come on theory next section. Ciao! K

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