1
RevNo
Revision note
6
Date
Signature Checked
BollAero 18
Designed by Chris Boll (UK)
Bore: 0.500 (12.7 mm)
Stroke: 0.560 (14.22 mm)
Displacement: 0.110 cuin (1.8cc)
Note:
The 1-1 Crankcase is symmetrical and may be reversed
to place the venturi and needle valve on the side that is
most convenient for the operator.
D
BollAero 18 - 3 Views
Drawn by
Chris Boll
CAD by
Ron Chernich
2009-10-27
Edition
1
Sheet
9
RevNo
2
Revision note
6
Date
Add deck height dimension
Signature Checked
2009-10-27
RC
n0.177 x THRU
0.500
12.70 mm
1.000
25.40 mm
0.438
11.11 mm
0.120
3.05 mm
5/16-24 UNF x 0.250
0.500
12.70 mm
4-40 UNC x 0.250
1.345
34.16 mm
0.290
7.37 mm
n0.890 x THRU
1.845
46.86 mm
0.500
12.70 mm
B
1.000
25.40 mm
0.398
10.11 mm
0.500
12.70 mm
0.398
10.11 mm
0.500
12.70 mm
0.398
10.11 mm
R0.675
R17.14 mm
n0.750 x 1.250
Fastner options
Drill #43 x 0.313
Tap 4-40
4 places on 1.126 PCD
6BA: Drill #42 to tap, #33 to clear.
4-40: Drill #43 to tap, #33 to clear
3.0Mx0.5: Drill 2.5mm tap, 3 mm to clear.
1-1 Crankcase
1.0 sq aluminium bar
0.398
10.11 mm
0.500
12.70 mm
1-1 Crankcase
D
BOLL-AERO 18 - Crankcase
Drawn by
Chris Boll
CAD by
Ron Chernich
2009-08-17
Edition
2
Sheet
1
RevNo
2
Revision note
Date
Signature Checked
Correct Attachment hole spacing and reposition hole callout.
2009-10-19
Ron C.
n0.750 x 0.500
[n19.05 x 12.70]
A
n1.500
n0.890
0.398
10.11 mm
0.500
(ref)
n22.61 mm
n0.114 x THRU
1.125 PCD [28.58]
(4 places)
n38.10 mm
12.70 mm
Countersink for
fastners size selected
0.398
10.11 mm
0.606
15.39 mm
0.400
10.16 mm
0.150
3.81 mm
n0.114 x THRU
(3 places)
0.606
15.39 mm
0.550
13.97 mm
2-1 Backplate
2-1 Backplate
n1-1/2 aluminium bar
4-40 x 1/4 Csk
Allen head screw
(4 reqd)
D
BOLL-AERO 18 - Backplate
Drawn by
Chris Boll
CAD by
Ron Chernich
2009-08-17
Edition
2
Sheet
2
RevNo
2
Revision note
Date
Add suggested radius dimension for turnmed journal to flange transition.
2009-10-19
n0.550
R0.062
R1.57 mm
1.000
25.40 mm
Signature Checked
Ron C
n0.114 x THRU
n13.97 mm
n0.313 x THRU
(ream)
1.000
25.40 mm
0.150
3.81 mm
n0.890
n22.61 mm
0.814
20.68 mm
0.170
4.32 mm
0.396
10.06 mm
0.396
10.06 mm
1.134
28.80 mm
3-1 Main Bearing Housing
1.0 sq aluminium bar
3-1 Main Bearing
4-40 x .375
Allen head screw
(4 reqd)
D
BOLL-AERO 18 - Main Bearing
Drawn by
Chris Boll
CAD by
Ron Chernich
2009-08-17
Edition
2
Sheet
3
RevNo
2
Revision note
Date
Signature Checked
Correct the note regarding milling depth of transfer passage.
2009-10-19
Ron C
0.316
8.03 mm
A
0.188
4.76 mm
n0.750
Mill Transfer passages 0.059" deep [1.5mm]
using a n3/16" slot-drill [5 mm] so top of
port reaches the top of the transfer port.
45
n19.05 mm
B
0.730
18.54 mm
0.120
3.05 mm
0.060
1.52 mm
1.402
35.61 mm
0.612
15.54 mm
0.290
7.37 mm
0.140
3.56 mm
C
Transfer port
drill 0.086 (#44)
[2.2mm]
2 places
Exhaust port drill n0.177 (#16)
n4.50 mm
n0.800
Inlet port drill n0.125
n3.18 mm
n20.32 mm
4-1 Cylinder
n7/8 12L14 Steel
n0.700
n17.78 mm
BOLL-AERO 18 - Cylinder
n0.500
n12.70 mm
Drawn by
Chris Boll
CAD by
Ron Chernich
2009-10-01
Edition
2
Sheet
4
RevNo
Revision note
6
Date
Signature Checked
n0.354 x 0.470
n0.433 x 0.200
2
3
Add Note 1.
Revise conrod cross section to circular.
2009-10-19
2009-10-26
Ron C.
Ron C.
A
Dome and polish ends (Note 1)
n0.157
n3.98 mm
0.625
15.88 mm
0.576
14.64 mm
0.200
5.08 mm
5-4 Contra-piston
0.275
6.99 mm
Section A-A
5-1 Piston
0.460
11.68 mm
n0.156
(ream)
5-1 Piston
5-3 Gudgeon Pin
n5/32" Drill Rod
Cast Iron
5-3 Gudgeon Pin
n0.156
n0.500
n3.96 mm
5-2 Conrod
n12.70 mm
n0.460 x 0.250
Section L-L
0.160
4.06 mm
n0.156 (ream)
n0.300
n7.62 mm
1.180
29.97 mm
Note 1.
n0.300
The -3 Gudgeon pin is a fully floating fit in the
-1 Piston and -2 Conrod. Dome and polish the
ends to prevent scoring of the 4-1 Cylinder Liner.
n7.62 mm
0.350
8.89 mm
Section B-B
n0.156 (ream)
0.250
6.35 mm
D
BOLL AERO 18 - Pistons and Rod
5-4 Contra-piston
5-2 Conrod
Cast Iron
2024 T3 Aluminium
Drawn by
Chris Boll
CAD by
Ron Chernich
2009-10-01
Edition
3
Sheet
5
RevNo
2
3
Revision note
Date
Signature Checked
Add Thread callout to -2 Compression Screw.
Correct the PCD note.
2009-10-19
2009-10-27
Ron C.
Ron C.
1/4-32 UNEF x THRU
0.188
4.76 mm
A
Drill n0.125 x THRU
on 1.126 PCD
(4 places)
4-40 Allen head screw
1.25 long
(4 reqd)
1.000
25.40 mm
n0.700
n0.125
0.625
15.88 mm
n17.78 mm
n3.18 mm
0.150
3.81 mm
0.100
2.54 mm
6-3 Tommy Bar
n0.250Thread 1/4-32
n6.35 mm
0.150
(Fin space typ)
3.81 mm
0.750
19.05 mm
6-2 Compression Screw
n1/4 Steel
0.050
(Fin typ)
Section C-C
0.550
13.97 mm
1.125
28.58 mm
n1.350
6-2 Compression
Screw
n0.125
1.27 mm
n3.18 mm
n34.29 mm
6-3 Tommy Bar
C
n1/8 Music Wire
Lightly chamfer edges
n0.500
6-1 Cylinder Head
n12.70 mm
BOLL AERO - Cylinder Muff
6-1 Cylinder Head
Drawn by
n1-3/8 aluminium bar
Chris Boll
CAD by
Ron Chernich
2009-10-01
Edition
3
Sheet
6
RevNo
n0.156 x THRU
n0.145 x 0.770
0.325
8.25 mm
Revision note
Date
Insert Centers.
2009-10-20
Signature Checked
Ron C
10-32 UNF x 0.500
0.010
0.25 mm
0.250
6.35 mm
0.280
7.11 mm
n0.500
A
n0.250
0.016
0.41 mm
n6.35 mm
n12.70 mm
10
0.030
0.76 mm
D
n0.850
n21.59 mm
0.375
9.53 mm
1.150
29.21 mm
n0.313
n7.94 mm
0.240
6.10 mm
n0.375
0.375
9.53 mm
n9.53 mm
n0.250
n6.35 mm
n0.272
n6.91 mm
7-1 Crankshaft
7-5 Collet
n7/8 stressproof steel, or HT bolt
0.125
3.18 mm
n3/8 Brass
Section D-D
n0.156
0.275
6.99 mm
n0.750
n19.05 mm
7-2 Crankpin
Loctite to 7-1 Crankshaft
n3.97 mm
0.099
2.51 mm
0.410
10.41 mm
10
C
7-2 Crankpin
n 5/32 Steel Roller or Drill Rod
n0.600
n15.24 mm
Section E-E
Plunge Knurl Face
7-1 Crankshaft
7-4 Prop Driver
n3/4 aluminium bar
7-3 Stud
1.000
25.40 mm
7-5 Collet
10-32 machine nut
7-4 Prop Driver
Alternate Threads:
2BA or 3/16 Whitworth
UNF 10-32
4Mx0.7
BOLL AERO 18 - Crankshaft
7-3 Stud
Drawn by
CAD by
Ron Chernich
2009-10-01
Cut from 10-32 machine screw
Edition
2
Sheet
7
1
Note 1:
RevNo
This sheet depicts the original crankshaft
and Prop Driver design. The method of
fixing the -4 Prop Driver is simpler than
that shown on Sheet 7, but may result in
a thrown prop.
0.325
8.25 mm
n0.850
n21.59 mm
B
0.125
3.18 mm
n3.97 mm
n12.70 mm
0.410
10.41 mm
n0.313
0.030
0.76 mm
0.450
11.43 mm
n0.145 x 0.770
Signature Checked
n0.156
n0.500
0.280
7.11 mm
Date
10-32 UNF x 0.375
n0.156 x THRU
Revision note
0.010
0.25 mm
0.250
6.35 mm
n7.94 mm
7a-2 Crankpin
1.150
29.21 mm
n 5/32 Steel Roller or Drill Rod
0.240
6.10 mm
n0.272
7a-1 Crankshaft
n6.91 mm
n7/8 stressproof steel, or HT bolt
7a-2 Crankpin
Loctite to 7a-1 Crankshaft
Section D-D
n0.750
n19.05 mm
10-32 UNF x THRU
0.275
6.99 mm
n0.500 x 0.016
0.100
2.54 mm
7a-1 Crankshaft
n0.600
n15.24 mm
Plunge Knurl face
7a-4 Prop Driver
n3/4 aluminium bar
7a-4 Prop Driver
(Note 1)
10-32 Machine Nut
1.375
34.93 mm
D
Alternate Threads:
2BA, or 3/16 Whitworth
UNF 10-32
4Mx0.7
7a-3 Stud
BOLLAERO 18 - Crankshaft (alt 1)
Drawn by
7a-3 Stud
Chris Boll
Cut from 10-32 machine screw
CAD by
Ron Chernich
2009-10-20
Edition
1
Sheet
7a
RevNo
Note 1: Drill -4 Prop Driver 0.240 (Letter "C") for a
force-fit on knurled section of -1 Crankshaft.
0.250
6.35 mm
0.280
7.11 mm
n0.850
n21.59 mm
0.031
0.79 mm
Revision note
Date
1.150
29.21 mm
0.325
8.25 mm
0.010
0.25 mm
Turn to n 0.250 [6.35 mm]
Apply course knurl.
Case Harden (opt).
Signature Checked
n0.156
n3.97 mm
10-32 UNF x 0.500
0.410
10.41 mm
n0.500
n12.70 mm
n0.156 x THRU
0.030
0.76 mm
0.375
9.53 mm
n0.145 x 0.770
n0.313
n7.94 mm
7b-2 Crankpin
n 5/32 Steel Roller or Drill Rod
0.240
6.10 mm
n0.272
0.125
3.18 mm
7b-1 Crankshaft
n6.91 mm
n7/8 stressproof steel, or HT bolt
-2 Crankpin
Loctite to -1 Crankshaft
Section D-D
0.100
2.54 mm
0.275
6.99 mm
n0.500 x 0.016
n0.550
7b-1 Crankshaft
n13.97 mm
n0.240 x THRU
n0.750
n19.05 mm
Plunge Knurl face
7b-4 Prop Driver
n3/4 aluminium bar
7b-4 Prop Driver
(Note 1)
10-32 Hex Machine Nut
1.000
25.40 mm
7b-3 Stud
Alternate Threads:
2BA or 3/16 Whitworth
UNF 10-32
4Mx0.7
BOLLAERO 18 - Crankshaft (alt 2)
Drawn by
7b-3 Stud
Ron Chernich
2009-10-20
Cut from 10-32 machine screw
CAD by
Edition
1
Sheet
7b
RevNo
n0.217 x THRU
Revision note
0.375
9.53 mm
n0.313
Date
n7.87 mm
0.125
3.18 mm
0.313
7.94 mm
F
0.313
7.94 mm
6
Signature Checked
n0.310
0.250
6.35 mm
n7.94 mm
5/16-24 UNF x THRU
0.250
6.35 mm
0.500
12.70 mm
8-4 Needle
0.010
0.25 mm
n0.146
0.438
11.11 mm
n3.70 mm
8-2 Jam Nut
7/16 AF Hex Brass
8-1 Venturi
5/16 sq Aluminium
8-5 Needle
Thimble
Section F-F
6-32 UNC x 0.375
1.500
38.10 mm
n0.188
6-32 Nut
n4.76 mm
14
0.250
6.35 mm
0.016
0.41 mm
0.500
12.70 mm
0.250
6.35 mm
8-4 Needle
n0.063 x THRU
n1/16 Music Wire
Section H-H
0.812
20.62 mm
8-2 Jam Nut
Drill thru #61
n0.055 x THRU
0.156
3.97 mm
8-5 Needle Thimble
n3/16 Brass
n0.188
8-1 Venturi
n4.76 mm
n0.173
n4.40 mm
n0.063 x 0.750
0.060
1.52 mm
n3.51 mm
Section G-G
Spraybar and Thimble: 6BA, 6-32 UNC. 3.5Mx0.6
Venturi and Jam Nut: 5/16-32 ME, 5/16-24 UNF, 8Mx1.25
D
BOLL AERO 18 - Fuel System
Alternate Threads
8-3 Spray Bar
n3/16 Brass
8-3 Spray Bar
n0.138
0.253
6.41 mm
Drawn by
Chris Boll
CAD by
Ron Chernich
2009-10-01
Edition
1
Sheet
8
