2024 CLONE ENGINE RULES
*It is the intent of Flat Run Speedway to make racing safe and secondly economical.*
**Clone Rules are based from AKRA**
***The differences make it practical to have a professionally built engine or a DIY engine with equal performance.***
****WE HAVE DEVELOPED TECH METHODS THAT DO NOT REQUIRE EXPENSIVE ENGINE TEARDOWNS.****
WE LOOK FORWARD TO 2024 AND HOPE TO SEE YOU ALL AGAIN
*It is the intent of Flat Run Speedway to make racing safe and secondly economical.*
**Clone Rules are based from AKRA**
***The differences make it practical to have a professionally built engine or a DIY engine with equal performance.***
****WE HAVE DEVELOPED TECH METHODS THAT DO NOT REQUIRE EXPENSIVE ENGINE TEARDOWNS.****
WE LOOK FORWARD TO 2024 AND HOPE TO SEE YOU ALL AGAIN
CLONE OHV 200 CLASS ~ Pump Gasoline Only
1. Engine must be stock bore and stroke. Machining of block and head allowed to obtain 26.5 cc combustion chamber volume. No other machining allowed. .010 Overbore allowed.
2. EXHAUST- mini pipe or open (big) pipe- muffler must be used and cannot extend beyond bumper.
Minimum length is 15"; Maximum length is 21"
3. Floor Mounted Fuel Tanks mandatory. Any pulse type fuel pump.
4. Clutches- disc or drum shoe type.
5. CARBURETOR- Huayi- Cpe- or Ruiing carb only- choke assembly must be in place and operational. Venturi .615" max and throttle bore .751" max. Any type aftermarket air filter (no ram air). Parts that can be removed through float bowl are non-tech.
Black phenolic insulator plate must be ran between carb. and head.
6. PISTON- clone dished piston and rings- No Honda pistons or rings. No oversize pistons.
7. CRANKSHAFT- clone crank only. Standard stroke + or -.010
8. FLYWHEEL- approved billet flywheel only- NO stock clone flywheel. min. 3.3 lbs.
9. IGNITION COIL must be standard clone. Timing- non tech
10. OEM Heads only- Porting allowed
Combustion chamber volume 26.5 cc minimum.
11.VALVE TRAIN- OEM parts only- valves may be standard or stainless steel but must be original diameter- valve seats 30, 45, 60 degrees allowed.
1.1 ratio stamped steel rocker arms only- no roller rockers.
Champion rocker arms may be used.
10.8 lb. valve springs max. diameter of .798" (wire diameter .071")
Seals may be used on both intake and exhaust (max. width/thickness .027")
Lash caps may be used on both intake and exhaust
Valve Seals are mandatory on the intake.
12. CAMSHAFT REQUIREMENTS:
~EZ. Spin must work
Maximum lift at valve retainer
Intake duration 219 degrees at .050 lift/ 86 degrees at .200 lift
Exhaust duration 222 degrees at .050 lift/ 97 degrees at .200 lift
(+2 degrees/ -5 degrees)
Legal cams are BSP1- BSP2- BSP3 / All dyno cams CL-1 thru CL-3 or any cam that meets above timing events.
13. FASTENERS- non-tech
14. GASKETS- non-tech
15. BEARING- crankshaft bearings must be metallic (no other
materials)
16. CONNECTING ROD- clone (OEM) or billet aluminum
17. BLOWER HOUSING ASSEMBLY- can use pull or electric starter.
1. Engine must be stock bore and stroke. Machining of block and head allowed to obtain 26.5 cc combustion chamber volume. No other machining allowed. .010 Overbore allowed.
2. EXHAUST- mini pipe or open (big) pipe- muffler must be used and cannot extend beyond bumper.
Minimum length is 15"; Maximum length is 21"
3. Floor Mounted Fuel Tanks mandatory. Any pulse type fuel pump.
4. Clutches- disc or drum shoe type.
5. CARBURETOR- Huayi- Cpe- or Ruiing carb only- choke assembly must be in place and operational. Venturi .615" max and throttle bore .751" max. Any type aftermarket air filter (no ram air). Parts that can be removed through float bowl are non-tech.
Black phenolic insulator plate must be ran between carb. and head.
6. PISTON- clone dished piston and rings- No Honda pistons or rings. No oversize pistons.
7. CRANKSHAFT- clone crank only. Standard stroke + or -.010
8. FLYWHEEL- approved billet flywheel only- NO stock clone flywheel. min. 3.3 lbs.
9. IGNITION COIL must be standard clone. Timing- non tech
10. OEM Heads only- Porting allowed
Combustion chamber volume 26.5 cc minimum.
11.VALVE TRAIN- OEM parts only- valves may be standard or stainless steel but must be original diameter- valve seats 30, 45, 60 degrees allowed.
1.1 ratio stamped steel rocker arms only- no roller rockers.
Champion rocker arms may be used.
10.8 lb. valve springs max. diameter of .798" (wire diameter .071")
Seals may be used on both intake and exhaust (max. width/thickness .027")
Lash caps may be used on both intake and exhaust
Valve Seals are mandatory on the intake.
12. CAMSHAFT REQUIREMENTS:
~EZ. Spin must work
Maximum lift at valve retainer
Intake duration 219 degrees at .050 lift/ 86 degrees at .200 lift
Exhaust duration 222 degrees at .050 lift/ 97 degrees at .200 lift
(+2 degrees/ -5 degrees)
Legal cams are BSP1- BSP2- BSP3 / All dyno cams CL-1 thru CL-3 or any cam that meets above timing events.
13. FASTENERS- non-tech
14. GASKETS- non-tech
15. BEARING- crankshaft bearings must be metallic (no other
materials)
16. CONNECTING ROD- clone (OEM) or billet aluminum
17. BLOWER HOUSING ASSEMBLY- can use pull or electric starter.