Hi, I've acquired a basket case comprising a '57 Model 77 frame and a '58 Dominator 600 motor, and I'm hoping somene can tell me which screw threads were used, before I make the wrong assumptions....
I'm specifically after what is used for the head steady bolts into frame, seat fixing studs, upper shock bolts, and the engine plates.
Thanks a lot
Robin
Threaded Holes â Iron Hea…
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Previously phil_hannam wro…
Yes And you get all these fittings at www.NooksNuts.co.uk in stainless or nickel plated there the nicest ones and these do not come undone and you get some free washers to if you put in a big order like I did Nooks-nuts are some of the best I seen and he now dose nylock nuts as well , I used them on my two NortonsThreaded Holes â Iron Heavy Twin Heads.
There are 6 different threads sizes used in total on this particular head.
Most threaded holes are tapped Cycle at 26tpi (with 60 degree thread angle) apart from the exhaust ports and the oil feed inlets.
The 3 head/barrel studs are 3/8 Cycle x 26tpi both ends as is the headsteady centre stud hole.
The oil feed inlets are 5/16 BSF x 22tpi.
The inlet rocker cover stud hole is 5/16 Cycle x 26tpi.
The intake port manifold stud holes and rocker spindle plate screw holes are both 1/4 Cycle x 26tpi
The exhaust rocker cover stud holes 1/4 Cycle x 26tpi.
Exhaust ports are 1-15/16 x 14tpi. The factory shop manual technical specification appears to be in error.
Threaded Holes - Aluminium Heavy Twin Heads.
All threaded holesare Whitworth form (with 55 degree thread angle).
Dominator & Atlas - forthe 3 head/barrel studs - 3/8 BSF x 20tpi
Atlas - headsteady centre stud hole - 3/8 BSF x 20tpi
Dominator & Atlas - intake rocker cover stud hole - 5/16 BSF x 22tpiDominator, Atlas- 2 oil inlet on top of head - 5/16 BSF thread x 22tpiDominator, intake port manifold - 1/4 BSW x 20tpi
650 & Atlas-intake port/manifold - 5/16 BSW x 18tpiDominator & Atlas- rocker spindle cover plate screws (pre 66-short) - 1/4BSWx 20tpi
Dominator & Atlas- exhaust rocker cover studs- 1/4 BSW x 20tpi
heavy twins
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Previously anna jeannette…
Previously anna jeannette Dixon wrote:
Previously phil_hannam wrote:Yes And you get all these fittings at www.NooksNuts.co.uk in stainless or nickel plated there the nicest ones and these do not come undone and you get some free washers to if you put in a big order like I did Nooks-nuts are some of the best I seen and he now dose nylock nuts as well , I used them on my two NortonsThreaded Holes â Iron Heavy Twin Heads.
There are 6 different threads sizes used in total on this particular head.
Most threaded holes are tapped Cycle at 26tpi (with 60 degree thread angle) apart from the exhaust ports and the oil feed inlets.
The 3 head/barrel studs are 3/8 Cycle x 26tpi both ends as is the headsteady centre stud hole.
The oil feed inlets are 5/16 BSF x 22tpi.
The inlet rocker cover stud hole is 5/16 Cycle x 26tpi.
The intake port manifold stud holes and rocker spindle plate screw holes are both 1/4 Cycle x 26tpi
The exhaust rocker cover stud holes 1/4 Cycle x 26tpi.
Exhaust ports are 1-15/16 x 14tpi. The factory shop manual technical specification appears to be in error.
Threaded Holes - Aluminium Heavy Twin Heads.
All threaded holesare Whitworth form (with 55 degree thread angle).
Dominator & Atlas - forthe 3 head/barrel studs - 3/8 BSF x 20tpi
Atlas - headsteady centre stud hole - 3/8 BSF x 20tpi
Dominator & Atlas - intake rocker cover stud hole - 5/16 BSF x 22tpiDominator, Atlas- 2 oil inlet on top of head - 5/16 BSF thread x 22tpiDominator, intake port manifold - 1/4 BSW x 20tpi
650 & Atlas-intake port/manifold - 5/16 BSW x 18tpiDominator & Atlas- rocker spindle cover plate screws (pre 66-short) - 1/4BSWx 20tpi
Dominator & Atlas- exhaust rocker cover studs- 1/4 BSW x 20tpi
heavy twins
Thanks, that helps.
Can anyone tell me the thread type in the frame for the two head steady bolts?
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Threaded Holes â Iron Heavy Twin Heads.
There are 6 different threads sizes used in total on this particular head.
Most threaded holes are tapped Cycle at 26tpi (with 60 degree thread angle) apart from the exhaust ports and the oil feed inlets.
The 3 head/barrel studs are 3/8 Cycle x 26tpi both ends as is the headsteady centre stud hole.
The oil feed inlets are 5/16 BSF x 22tpi.
The inlet rocker cover stud hole is 5/16 Cycle x 26tpi.
The intake port manifold stud holes and rocker spindle plate screw holes are both 1/4 Cycle x 26tpi
The exhaust rocker cover stud holes 1/4 Cycle x 26tpi.
Exhaust ports are 1-15/16 x 14tpi. The factory shop manual technical specification appears to be in error.
Threaded Holes - Aluminium Heavy Twin Heads.
All threaded holesare Whitworth form (with 55 degree thread angle).
Dominator & Atlas - forthe 3 head/barrel studs - 3/8 BSF x 20tpi
Atlas - headsteady centre stud hole - 3/8 BSF x 20tpi
Dominator & Atlas - intake rocker cover stud hole - 5/16 BSF x 22tpiDominator, Atlas- 2 oil inlet on top of head - 5/16 BSF thread x 22tpiDominator, intake port manifold - 1/4 BSW x 20tpi
650 & Atlas-intake port/manifold - 5/16 BSW x 18tpiDominator & Atlas- rocker spindle cover plate screws (pre 66-short) - 1/4BSWx 20tpi
Dominator & Atlas- exhaust rocker cover studs- 1/4 BSW x 20tpi