9HP JR. LATE MODEL TECHNICAL RULES
Body must be straight, sound, stock appearing and in stock position on frame. Alterations or customizing to gain any advantage is prohibited. Original wheel arches must be retained. Original body seams must be retained. No hood pins or fastenings devices out-
NOTE: Both front fenders (considered being from nose of car to the number on the door) and windshield banner shall be completely free of lettering of decals. JCAR retains the right to specify type, size and location of all decals on front fenders and windshield.
NOTE: Mini cup chassis use 1” o.d. x .085 d.o.m.
NOTE: If running head and neck restraints (HAANS) is worn. You do not need neck collar If using a HAANS both head support are MANDATORY.
Weight must be securely bolted between outer frame rails and behind front axle and a head of rear axle centers. With a welded in bracket with 2 bolts and painted white with your number on it .
OLD STYLE ENGINE SPECIFICATIONS
** All parts may be compared with known Honda parts to verify their originality. One off parts will be considered unacceptable manufactures deviations.
ALL DECISIONS BY PIT STEWARDS, CHIEF TECHNICAL INSPECTOR OR JCAR EXECUTIVE COMMITTEE MEMBERS WILL BE FINAL, ALL RULES SUBJECT TO INTERPRETATION BY JCAR OFFICIALS. RULEBOOKS WILL BE ISSUED TO MEMBERS
GOVERNED BY THE AFOREMENTIONED RULES ARE TO BE SUBMITTED TO JCAR, NOT LESS THAN 30 DAYS PRIOR TO THE DATE OF INTENDED USAGE. NO EQUIPMENT WILL BE CONSIDERED APPROVED BY REASON OF HAVING PASSED THROUGH INSPECTION UNOBSERVED. RULES APPLY TO ALL RACE EVENTS.
> CARBS – no intchangeing of carbs between motors New with New / Old with old
1. Governor may be removed
2. Decompressor must not be removed
3. Block may be bored to the three Honda oversize
4. Piston dish may be a minimum of .037
5. Piston may be a minimum of .038 below deck
6. Stock Honda rings must be used & installed properly
7. Any ring gap allowed
8. Stroke shall be a maximum of 58mm or 2.287
9. Stock or .010 undersized rods allowed
10. Stock or billet cleaner allowed
11. Any heat range spark plug as stock reach
12. Stock 25K valves & keepers, stellite exhaust allowed
13. Valves may be refaced but not excessively
14. Any valve spring allowed
15. Stock carb jet & emulsion tube allowed NO jets larger than 92 allowed . NO MODIFIED CARBS
16. Carb must be BE21JA model
17. Minimum head CC is 25
18. Minimum cylinder head thickness is 3.728
19. Head gasket is steel .009 thickness
20. Any flywheel air gap allowed
21. Any vacuum operated fuel pump allowed
22. Only stock ignition timing with stock key allowed
23. Only early style flywheel & coil allowed (fixed timing)
24. Carb throttle bore is .832 max
25. Carb venturi bore is .676 max
26. Camshaft intake lobe height is 1.265 max 1.250 min
27. Camshaft exhaust lobe height is 1.255 max 1.245 min
28. Max lift at intake valve at 0 lash is .282
29. Max lift at exhaust valve at 0 lash is .270
30. Camshaft must have stock lobe separation angle
31. Three angle seat grind allowed
32. No porting, no deburring, no matching