NOZZLE NUMBERS: Every nozzle is engraved with a number indicating the throat size in 64ths of an inch. For example, a #24 nozzle has a 24/64″ = 0.375″ throat diameter. Isn`t that nice? No more guessing what that nozzle in the bottom of your range box is.
Suggested EX Nozzle throats are based on the use of typical packable EX propopellant formulations and are meant as a starting point.
The best throat sizes for each hardware size are based off of the desired operating chamber pressure, which is dependant upon the specific propellant formulation, processing methods and grain geometry used.
| Motor Diameter |
Case Length |
Case Wall | Aprox. Total Impulse |
Liner length |
Max Propellant Length |
ID of casting tube |
Commercial Nozzle throat | Suggested EX Nozzle throat |
Typical Bates Grain Geometry |
| 29 mm | 5.5″ | 0.058″ | 120 | 3.5″ | 3.25″ | #13 | Two 1-5/8″ long grains with 3/8″ cores | ||
| 29 mm | 7″ | 0.058″ | 180 | 5.12″ | 4.88″ | #15 | Three 1-5/8″ long grains with 3/8″ cores | ||
| 29 mm | 8.6″ | 0.058″ | 240 | 6.75″ | 6.35″ | #18 | Four 1-5/8″ long grains with 3/8″ cores | ||
| 29 mm | 11.8″ | 0.058″ | 360 | 10″ | 9.75″ | #22 | Six 1-5/8″ long grains, four with 3/8″ cores and two with 7/16″ cores | ||
| 29 mm | 15.1″ | 0.058″ | 460 | 13.25″ | 13″ | #25 | Six 1-5/8″ long grains, four with 3/8″ cores and two with 7/16″ cores, plus one 3-1/4″ grain with a 7/16″ core | ||
| 38 mm | 4.81″ | 0.083″ | 120 | 2.937 | 2.4 | 1.212 | #10 | #11 | One 2.375″ long grain with 7/16″ core. |
| 38 mm | 7″ | 0.083″ | 240 | 5.063″ | 4.6″ | 1.212″ | #16 | #16 | Two 2.25″ long grains with 7/16″ cores |
| 38 mm | 11.5″ | 0.083″ | 480 | 9.5625″ | 9.1″ | 1.212″ | #19 | #22 | Four 2.25″ long grains with 1/2″ cores |
| 38 mm | 16″ | 0.083″ | 740 | 14.063″ | 13.6″ | 1.212″ | #22 | #28 | Six 2.25″ long grains with 1/2″ cores |
| 38 mm | 24.625″ | 0.083″ | 1200 | 22.6875″ | 21.75″ | 1.212″ | #28 | #28 | Six 3.7″ long grains with 1/2″ cores. (Hold on tight) |
| 54 mm | 9.850″ | 0.094″ |
950 |
7.375″ | 6.8″ | 1.755″ | #19 | #24 | Three 2.265″ long grains with 1/2″ cores |
| 54 mm | 12.875″ | 0.094″ | 1200 | 10.375″ | 9.81″ | 1.755″ | #24 | #29 | Three 3.25″ long grains with 5/8″ cores |
| 54 mm | 15.875″ | 0.094″ | 1600 | 13.375″ | 12.81″ | 1.755″ | #26 | #33 | Four 3.2″ long grains with 5/8″ cores |
| 54 mm | 19.375″ | 0.094″ | 2000 | 16.875.” | 16.25″ | 1.755″ | #29 | #36 | Four 3.25″ long grains with 5/8″ cores and one 3.25″ long grain with 3/4″ core |
|
54mm |
28.625 Gen 1 28.525″ Gen 2 |
0.094″ | 2800 |
26.05″ (Std) 27.13″ (Ext.) |
25.48 (Std.) 26.68″ (Ext.) |
1.755″ |
#42 Single Use |
#44 | One 4.15″ and Five 4.25″ long grains with 13/16″ cores. |
|
54mm |
43.85″ Gen 1 43.75″ Gen 2 |
0.094″ | 4000 | 42.375″ | 41.92″ | 1.755″ | Single Use |
Gen 1 -Snap ring end margins were 0.250″. Gen 2 – Snap ring end margins are 0.200″ – Distance from front of thrust ring to back of case is now 0.425″. This is now the same as all other current 54mm Loki Research cases. |
|
| 76 mm | 14.5″ | 0.116″ | 2400 | 11.49″ | 10.7″ | 2.551″ | #28 | #32 | Two 5.34″ long grains with 3/4″ cores |
| 76 mm | 19-5/8″ | 0.116″ | 3600 | 16.937″ | 15.75″ | 2.551″ | #40 | #40 | Three 5.25″ long grains with 3/4″ cores |
| 76 mm | 25.0″ | 0.116″ | 4800 | 22.3″ | 21.2″ | 2.551″ | #48 | Four 5.25″ long grains with 7/8″ cores | |
| 76 mm | 30-7/8″ | 0.116″ | 6000 | 27.187″ | 26.05″ | 2.551″ | #52 | #52 | Four 5.25″ long grains with 7/8″ cores and one 5″ long grain with a 1″ core |
| 76 mm | 40-7/8″ | 0.116″ | 8000 | 37.187″ | 36.05″ | 2.551″ | #56 | #60 | Five 6″ long grains with 1″ cores and one 6″ long grain with a 1-1/8″ core |
| 76 mm | 57.0″ | 0.116″ | 13000 | 53.312″ | 51.95″ | 2.551 | #80 | Propellant dependant | |
| Historical | Information | Only | Below | Not | In | Production | |||
| 98 mm | 18″ | 0.188″ | 5000 | 13.75″ | 12″ | 3.225″ | #44 | Two 6″ long grains with 1.25″ cores | |
| 98 mm | 24″ | 0.188″ | 7500 | 19.75″ | 18″ | 3.225″ | #52 | Three 6″ long grains with 1.25″ cores | |
| 98 mm | 30″ | 0.188″ | 10000 | 25.75″ | 24″ | 3.225″ | #60 | Four 6″ long grains with 1.25″ cores | |
| 98 mm | 40″ | 0.188″ | 12500 | 36.125″ | 34.625″ | 3.225″ | #64 | #76 | Six 5-3/4″ long grains with 1.5″ cores |
| 98 mm | 47-7/8″ | 0.188″ | 16000 | 44.0″ | 42.625″ | 3.225″ | #80 | ||
| 114 mm | 18″ | 0.237″ | 6000 | 13.75″ | 12″ | 3.8″ | #48 | Two 6″ long grains with 1.5″ cores | |
| 114 mm | 24″ | 0.237″ | 9000 | 19.75″ | 18″ | 3.8″ | #60 | Three 6″ long grains with 1.5″ cores | |
| 114 mm | 30″ | 0.237″ | 12000 | 25.75″ | 24″ | 3.8″ | #64 | Four 6″ long grains with 1.5″ cores | |
| 114 mm | 52″ | 0.237″ | 22000 | 45.75″ | 44″ | 3.8″ | #90 |
O-ring Info
| Motor Size | ID | OD | Width | Dash number |
| 29 mm | 7/8″ | 1″ | 1/16″ | 020 |
| 38 mm | 1-1/8″ | 1-3/8″ | 1/8″ | 215 |
| 54 mm | 1-5/8″ | 1-7/8″ | 1/8″ | 223 |
| 54 mm Bulkhead/Liner Shoulder | 1-5/8″ | 1-13/16″ | 3/32″ | 130 |
| 76 mm | 2-1/2″ | 2-3/4″ | 1/8″ | 230 |
| 76 mm Bulkhead/Liner Shoulder | 2-7/16″ | 2-5/8″ | 3/32″ | 143 |
| 98mm | 3-1/4″ | 3-1/2″ | 1/8″ | 236 |
| 114 mm | 3-3/4″ | 4″ | 1/8″ | 240 |
| 152 mm | 5″ | 5.5″ | 3/16″ | 354 |
* In 38mm -215 or -216 can be used. The smaller -215 rings are a tight fit and can be difficult to remove from the nozzle. The larger -216 rings are a loose fit and can be harder to push into the case. I use -215 for both Buna-N and Silicone ring material for use in Loki Research reloads.
38mm Delay o-rings are -113
54mm Standard Smoke o-rings are -120
54mm Extended Bulkhead smoke and 76mm smoke grain o-rings are -120
Nozzle Exit Diameters
38mm
#10 thru #15 = 0.470″
#16 thru #18 = 0.630″
#19 thru #24 = 0.780″
#25 and up = 0.900″
54mm
#19 thru #23 = 0.850″
#24 thru #28 = 1.000″
#29 and up = 1.250″
76mm
#28 thru #39 = 1.255″
#40 thru #51 = 1.500″
#52 and up = 1.818″
76mm nozzle exits up to 2.0″ are available upon request for an additional machining fee, however this removes more graphite material, thus weakening the part and making it more vulnerable to cracking.