As many of you are aware we have formed a 600cc engine rules committee to try to define a working set of rules for the use of 600cc 4 stroke motorcycle engines for use in F500. We have essentially used the format of the engine rules for FB (F1000) as these rules are very well formulated and have been approved by the CRB & the BOD.
We have been in contact with members of both the CRB & the BOD in an effort to understand the process and to make sure that we are preparing this correctly.
Please be aware that this is a DRAFT of a proposal and there may certainly be changes as needed prior to sending any proposal to the CRB & BOD for their review.
We are asking for the input of all interested parties in an effort to make this proposal as functional as possible.[
Also note that our efforts are intended to make CERTAIN that current F500 cars remain absolutely competitive and that the class philosophy of the utmost value in low cost racing is maintained or improved.
The list of engine rules definitions are drawn directly from the FB (F1000) rules in the GCR. As such they also follow the same format and numbering. The numbering format will change if & when this rules proposal is submitted for approval to the SCCA.
(Current engine & associated rules from the F1000 section of the GCR with our suggested modifications in RED)
H.4. Engines
A. Motorcycle-based 4-cycle engines up to 600cc. Engines shall be approved production engines supplied by the following manufacturers; Honda, Kawasaki, Suzuki and Yamaha. The list of approved manufacturers may be modified by the CRB.
B. Engine internals and compression ratio must remain stock. The competitor must present, on demand, an original factory manual for the engine to allow compliance verification. There shall be no modification of any component of the engine unless specifically authorized in these rules.
C. The stock ECU shall be used. The ECU fuel map may be changed. Devices that modify inputs to the ECU (e.g., Power Commander) may be used. Stand-alone after market ECUs are not permitted.
D. Turbochargers and superchargers are prohibited.
E. Carburetion and fuel injection are unrestricted.
F. The exhaust system and exhaust manifold are unrestricted, within SCCA safety regulations, except that stepped exhaust headers are not allowed.
G. The lubrication system is unrestricted except that dry sump systems are not permitted; any oil pan and/or baffling is permitted and the use of Accusump or similar oiling assist systems are allowed.
H. Oil coolers are unrestricted.
I. The cooling system is unrestricted. Radiators and associated ductwork shall comply with with existing F500 bodywork rules.
J. Replacement of the stock camshaft chain tensioner with any other chain tensioner is allowed. The replacement chain tensioner must attach directly to the engine in the original chain tensioner position. There shall be no modifications to the engine to enable the use of the replacement chain tensioner.
K. Replacement of the standard connecting rod fasteners with alternate fasteners is allowed as long as there are no modifications to the connecting rods.
L. The engine head gasket must be the thickness of the OEM gasket for the year and model of the engine.
M. Camshafts and camshaft drive mechanisms cannot be modified or adjusted in any way unless specifically specified in these rules.
N. Engine rev limits must not be modified from the stock as defined in the shop manual. There shall be no modifications to the ECU to allow for higher than specified rev limits.
H.5. Inlet Restrictors
A. The air inlet system is unrestricted at this time. However, the CRB may require the use of an inlet restrictor at any time by publishing the requirements in FasTrack.
H.6. Fuel system
The fuel system is unrestricted within the following limitations:
A. Fuel Cell Vents: Fuel tank air vents shall be located at least 25cm to the rear of the cockpit.
B. Fuel capacity: maximum 6.0 gallons.
H.7. Electrical System
The electrical system is unrestricted within the following limitations:
A. Self-starter: Cars shall be equipped with an on-board self-starter and an on-board power supply controlled by the driver while in a normal driving position.
H.8. Transmission/Final Drive
A. Rear wheel drive only is permitted.
B. The final drive ratio is unrestricted. Internal transmission gears shall remain stock.
C. Cars may use sequentially shifted motorcycle transmissions. Reverse gear is not required.
D. All gear changes must be initiated by the driver. Only mechanical gear shifting mechanisms are allowed. This shall include cables, rods, or other mechanical linkage systems. Other assisted shifting mechanisms are specifically not allowed. This shall include electric solenoid shifters, air-shifters etc. Other similar devices are NOT permitted. Devices that allow pre-selected gear changes are also prohibited.
E. The clutch assembly is unrestricted except that the clutch engagement system shall be operated solely by driver input and shall be mechanical or hydraulic in nature. The clutch must be manually operated by the drivers hands or feet and there shall be no operation of the clutch by any assisted method.
F. The use of jackshafts to transmit power from the output sprocket to the rear axle is allowed.
G. Chain tensioners are allowed.
From the F500 rules:
E.2. Weight and Dimensions
Minimum weight as qualified and raced, with driver, shall be 700 pounds (800 lbs. for AMW and Rotax 494 engines, 825 lbs. for Rotax 493, 835 lbs for 4 stroke 600cc motorcycle engines).
Wheelbase: Maximum 80"
Overall Length: Minimum 110”
Maximum 150”
Overall Width: Minimum 50”
Maximum 55”
Thanks ... Jay Novak