Whoooo! That Australian thing with the puffer is scary. If it had ten more rear tires it might have enough traction.
Production and Modified Production frame class have a maximum of 3,000 cc.
Special Construction, Streamliner, Sidecar, and Sidecar Streamliner frame classes have no limit. (Unlimited 3001 and above). Why stop at 15,000 cc?
The following shows what you can do when watching a dull movie with a laptop in front of you.
To run, you need a Body Code from Appendix A Vehicle Data Codes. A Body code is a frame class and an engine class combination.
Production (P) frame class can run P (425), PP (426), PB (427), PV (488), PPB (489) engine class and are limited to motorcycle engines.
Modified Production (M) (and Modified Production Partially Streamlined) (MPS) frame class (Bonneville only) can run PG (459, 467), VG (475, 471), PBG (457, 465), VBG (473, 469), PF (458, 466), VF (474, 470), PBF (456, 464), VBF (472, 468) engine classes and are limited to motorcycle engines. Those two frame classes can also run F (454, 462), G (455, 463), BF (452, 460), BG (453, 461) engine classes and are comprised of major parts and components designed primarily for use in motorcycle engines.
Special Construction (A) (and Special Construction Partially Streamlined) (APS) frame class can run PG (408, 416), VG (424, 420), PBG (406, 414), VBG (422, 418), PF (407, 415), VF (423, 419), PBF (405, 413), VBF (421, 417) engine classes and are limited to motorcycle engines. Those two frame classes can also run F (403, 411), G (404, 412), BF (401, 409), BG (402, 410) engine classes and are comprised of major parts and components designed primarily for use in motorcycle engines. And omega (but only in partially streamlined!)
Streamliner (S) frame class can run PG (447), VG (451), PBG (445), VBG (449), PF (446), VF (450), PBF (444), VBF (448) engine classes and are limited to motorcycle engines. This frame class can also run F (442), G (443), BF (440), BG (441) engine classes and are comprised of major parts and components designed primarily for use in motorcycle engines. And omega.
Sidecar (SC) frame class can run PG (435), VG (439), PBG (433), VBG (437), PF (434), VF (438), PBF (432), VBF (436) engine classes and are limited to motorcycle engines. This frame class can also run F (430), G (431), BF (428), BG (429) engine classes and are comprised of major parts and components designed primarily for use in motorcycle engines.
Sidecar Streamliner (SCS) frame class can run PG (483), VG (487), PBG (481), VBG (485), PF (482), VF (486), PBF (480), VBF (484) engine classes and are limited to motorcycle engines. This frame class can also run F (478), G (479), BF (476), BG (477) engine classes and are comprised of major parts and components designed primarily for use in motorcycle engines.
Unlimited Gas (UG) engine class and Unlimited Fuel (UF) engine class (type of engine, not cc) run in Streamliner, Sidecar, and Sidecar Streamliner. Car engines can run here. Good luck with that. There is no vehicle data code.
There is an engine code (216) (where you would normally see cc's) for steam, turbine or electric.
There is also a body code (490) for Omega. Good luck with that one too.
It's all in Appendix A.
Willie? Did I cover it?