- Sun Oct 30, 2011 12:36 pm
#279530
Section 8.1 lists all allowable modifications in H1-H5
I'd stay away from H1, people spend World Challenge money there. I would jump into H2 using a B20 in a CRX or EF civic.
- Tue Nov 01, 2011 4:27 am
#279694
H4 and H2 usually have the biggest classes.
Body swaps are legal as long as there is not an structural advantage. The only car this really applies to is the ITR.
Section 8 lists all allowances for all classes and section 8.1 tells you exactly what you can do to the motor in ALL CLASSES. The following sections for H1 and H2 are supplemental to those individual classes. These are the only motor mods that can be done in H4. I forgot to add that most H4 prepped cars are eligible for SCCA IT classes also.
8.1 Engine
a) Engines may be balanced and/or blueprinted. Lightning of moving parts beyond what is necessary to
balance is prohibited. Engine bearings may be replaced with aftermarket replacements and engine
clearances (piston to wall, valve lash, etc) are unrestricted and are considered blueprinting.
b) Engines may be bored to a maximum of .040 inch (1 mm) over standard bore size. c) Factory replacement pistons or the exact equivalent shall be used. Exact equivalent shall be defined as
the same dome/dish/valve relief configuration, weight, ring thickness and location, and pin location as
the OEM replacement piston. Wrist pins and method of retention must also conform to OEM
specifications. In the event that a .040 factory replacement piston/wrist pin is not available, the oversize
pistons/wrist pins shall not weigh any less than the largest size OEM piston for that engine.
d) Piston rings are unrestricted but must be of proper OEM ring thickness.
e) Cylinder head intake ports, exhaust ports, and intake manifold may be port matched but cannot be
machined beyond one (1) inch into the head or intake.
f) Valve face where it mates to the seat may be machined and valve seats may be machined for the
purposes of a valve job. Valves may only be replaced with the exact OEM equivalent, with exception of
valve job.
g) Valve guide material is unrestricted. However, shape and size must remain the same as OEM.
h) Compression may be increased one half (.5) a point greater than OEM number.
i) Cylinder head gasket surfaces may be machined so long as it does not increase compression beyond
the maximum value allowed for make and model.
j) Timing gears must remain OEM. Cars equipped from the factory with plastic timing gears may replace
them with metal gears so long as cam timing remains stock. OEM crank timing gear may be adjusted
with an offset key back to stock position. Offset keys may be used with cam gears on SOHC engines
only.
k) Any OEM Honda or Acura ECU (including other models, domestic markets (JDM) and generations) may
be used, and may be relocated ONLY to facilitate cage installation. Reprogramming of OEM ECU is
allowed. Piggyback ECU’s that plug into the OEM ECU (e.g. Hondata) are allowed. VAFC
(VTEC/Air/Fuel) controllers or other devices that perform the same function may be used. AEM
Standalone ECU is permitted. OBD0 equipped cars may update distributor and associated wiring to
OBD1 or OBD2. This includes the use of a “jumper harness†to convert the OBD0 wiring of the stock
ECU plugs to work with the OBD1 or OBD2 ECU.
l) Polyurethane or hard rubber motor mounts and/or inserts may be used.
m) Any air intake system in front of the throttle body (including mass air sensor) may be used (stock throttle
body must be retained).
n) Carbureted vehicles may use an alternate carburetor of the same design and configuration (for example,
a single barrel can be replaced with an alternate single barrel, but not a dual barrel).
o) Any exhaust manifoldheader and exhaust system may be used. All emission related devices may be
removed or disabled. Catalytic converters may be removed. NOTE: Some facilities have rules governing
sound limits. Vehicles must fall within these limits to be allowed to compete.
p) Fasteners may be replaced with items of unrestricted origin, but performing the exact OEM function.
q) Gaskets (including the use of phenolic spacers) may be replaced with others of unrestricted origin so
long as they do not violate any other rules contained herein.
r) Engine drive belts may be replaced with others of unrestricted origin.
s) Alternate accessory drive pulleys (“underdrive pulleysâ€) may be used. Crankshaft may use any pulley
(size and material unrestricted).
t) Alternate water pumps of OEM design may be used and must bolt to engine without modification.
u) Cars equipped with vacuum advance distributors may perform necessary distributor modifications to
install other Honda electronic advance distributors.
Body swaps are legal as long as there is not an structural advantage. The only car this really applies to is the ITR.
Section 8 lists all allowances for all classes and section 8.1 tells you exactly what you can do to the motor in ALL CLASSES. The following sections for H1 and H2 are supplemental to those individual classes. These are the only motor mods that can be done in H4. I forgot to add that most H4 prepped cars are eligible for SCCA IT classes also.
8.1 Engine
a) Engines may be balanced and/or blueprinted. Lightning of moving parts beyond what is necessary to
balance is prohibited. Engine bearings may be replaced with aftermarket replacements and engine
clearances (piston to wall, valve lash, etc) are unrestricted and are considered blueprinting.
b) Engines may be bored to a maximum of .040 inch (1 mm) over standard bore size. c) Factory replacement pistons or the exact equivalent shall be used. Exact equivalent shall be defined as
the same dome/dish/valve relief configuration, weight, ring thickness and location, and pin location as
the OEM replacement piston. Wrist pins and method of retention must also conform to OEM
specifications. In the event that a .040 factory replacement piston/wrist pin is not available, the oversize
pistons/wrist pins shall not weigh any less than the largest size OEM piston for that engine.
d) Piston rings are unrestricted but must be of proper OEM ring thickness.
e) Cylinder head intake ports, exhaust ports, and intake manifold may be port matched but cannot be
machined beyond one (1) inch into the head or intake.
f) Valve face where it mates to the seat may be machined and valve seats may be machined for the
purposes of a valve job. Valves may only be replaced with the exact OEM equivalent, with exception of
valve job.
g) Valve guide material is unrestricted. However, shape and size must remain the same as OEM.
h) Compression may be increased one half (.5) a point greater than OEM number.
i) Cylinder head gasket surfaces may be machined so long as it does not increase compression beyond
the maximum value allowed for make and model.
j) Timing gears must remain OEM. Cars equipped from the factory with plastic timing gears may replace
them with metal gears so long as cam timing remains stock. OEM crank timing gear may be adjusted
with an offset key back to stock position. Offset keys may be used with cam gears on SOHC engines
only.
k) Any OEM Honda or Acura ECU (including other models, domestic markets (JDM) and generations) may
be used, and may be relocated ONLY to facilitate cage installation. Reprogramming of OEM ECU is
allowed. Piggyback ECU’s that plug into the OEM ECU (e.g. Hondata) are allowed. VAFC
(VTEC/Air/Fuel) controllers or other devices that perform the same function may be used. AEM
Standalone ECU is permitted. OBD0 equipped cars may update distributor and associated wiring to
OBD1 or OBD2. This includes the use of a “jumper harness†to convert the OBD0 wiring of the stock
ECU plugs to work with the OBD1 or OBD2 ECU.
l) Polyurethane or hard rubber motor mounts and/or inserts may be used.
m) Any air intake system in front of the throttle body (including mass air sensor) may be used (stock throttle
body must be retained).
n) Carbureted vehicles may use an alternate carburetor of the same design and configuration (for example,
a single barrel can be replaced with an alternate single barrel, but not a dual barrel).
o) Any exhaust manifoldheader and exhaust system may be used. All emission related devices may be
removed or disabled. Catalytic converters may be removed. NOTE: Some facilities have rules governing
sound limits. Vehicles must fall within these limits to be allowed to compete.
p) Fasteners may be replaced with items of unrestricted origin, but performing the exact OEM function.
q) Gaskets (including the use of phenolic spacers) may be replaced with others of unrestricted origin so
long as they do not violate any other rules contained herein.
r) Engine drive belts may be replaced with others of unrestricted origin.
s) Alternate accessory drive pulleys (“underdrive pulleysâ€) may be used. Crankshaft may use any pulley
(size and material unrestricted).
t) Alternate water pumps of OEM design may be used and must bolt to engine without modification.
u) Cars equipped with vacuum advance distributors may perform necessary distributor modifications to
install other Honda electronic advance distributors.
- Tue Nov 01, 2011 7:36 pm
#279760
Yes, that is a H4 legal swap.
Negative on the high compression pistons.
Factory replacement pistons or the exact equivalent shall be used. Exact equivalent shall be defined as
the same dome/dish/valve relief configuration, weight, ring thickness and location, and pin location as
the OEM replacement piston. Wrist pins and method of retention must also conform to OEM
specifications. In the event that a .040 factory replacement piston/wrist pin is not available, the oversize
pistons/wrist pins shall not weigh any less than the largest size OEM piston for that engine.
Its all right in front of you, and if the rule book does not mention something then it's not legal.
Negative on the high compression pistons.
Factory replacement pistons or the exact equivalent shall be used. Exact equivalent shall be defined as
the same dome/dish/valve relief configuration, weight, ring thickness and location, and pin location as
the OEM replacement piston. Wrist pins and method of retention must also conform to OEM
specifications. In the event that a .040 factory replacement piston/wrist pin is not available, the oversize
pistons/wrist pins shall not weigh any less than the largest size OEM piston for that engine.
Its all right in front of you, and if the rule book does not mention something then it's not legal.