Regular Season HMS Four Cylinder Rules Will Be Released at a Later Date


Competition will be open to 1962 and later models of American or Foreign four passenger sedans sold in the United States. No Cosworth Vegas. No Mid Engine or all wheel drives.


Stock OEM configuration steel front fenders, roof and rear quarter panels will be considered “stock”. May fabricate stock appearing metal doors and trunk lid. Aftermarket nose, tail and hood allowed. Metal, fiberglass or plastic. May interchange body on chassis make and model. Full aftermarket bodies allowed. Full aftermarket bodies and bodies interchanged chassis vs. make model. No addition to total weight. No open rear sections, minimum rear bumper cover height is 18 inches. No open wheel bodies. Bodies must be of a stock car type appearance. Hood and deck lid must have positive magnetic steel type fasteners. Inner body panels may be removed but must be safe and neat appearing. Headlight and tail light openings must be covered.


Aftermarket body must maintain a minimum or 44 inches in height when measured 10 inches back from the center of the windshield.


Rear spoiler can be a maximum of 5 inches and no wider then the rear deck.


All cars must use a complete metal dash.


OEM factory suspension only for make and model of chassis being used. No full tube cars with aftermarket suspensions. Upper A-frames may be cut. Adjuster cups or wedge bolts permitted. Lower control arms must be stock for year, make and model of car. May not use longer, later model Mustang 6 cyl A-arm on earlier models. All mounting points on the front lower unit must be in stock location. OEM spindles must be used and not altered except for adding bracing. Mono-Balls are permitted in the suspension. Neoprene and solid bushings are allowed. May use sliders, wedge bolts or extended shackles on leaf springs . Rear control arms must be stock OEM type. Stock type coil over strut kits may be used on cars that came with spring over strut design. EX: Toyota Corolla . Strut towers may be removed.


Any front anti-sway bar mechanism allowed. No Late Model sway bars with arms. No rear anti-sway bars. Must use heim joints on sway bar linkages. Must use OEM steering rack and/or linkages. OEM Ford pack and pinion may be used on other makes. May use heim joints where steering rod ends meet spindle steering arm for bump-steer correction.


Firewall required and must fully shield driver from the engine compartment. Rear firewall may be stock or fabricate. No less then 24 gauge steel and must separate driver from the fuel cell.


Factory floor pan must extend from the front firewall to the rear firewall. May fabricate wheel wells and crush panels but they must be metal if part of either firewall. Floor pan may be patched. Must be steel patchwork of at least 24 gauge. Floor pan may be minimally altered to accommodate exhaust systems extending thru the firewall, but safety will be at the discretion of the officials. Front and rear chassis may be connected with tubing that protrudes thru floor pan. Tubing may replace rocker panels.


All chassis to suspension control arm mounting points must be of OEM dimensions. And relative heights. Including, Front A-arms, rear upper and lower trailing arms , steering rack and pan hard bar. Uni-body design chassis may be tied together. No under slung rear chassis. No full tube chassis. Original chassis rails must be in tack from front cross member mounting to centerline of rear axle. Aftermarket tubing clip extensions must mount cross-member, suspension parts and steering rack in OEM location, and the majority of the front clip and rear chassis rails must still be present to measure relative to. Considers will be made for wrecked and repaired chassis at the tech-mans discretion. Stock front cross member must be used.


Wheelbase must match year of car being used. 64 inch tread width maximum. 101 inch wheelbase length maximum allowed.


Race height 5 inch minimum with driver, checked at pinch weld or chassis. Which ever is lower. Ride height will be checked down length of left side of car between wheels. Minimum nose valence height is 4 inches.



Refer to NASCAR LMSC guidelines for minimum requirements.


OEM 4 cylinder engines . No 3 / 4 / 5 valve or double overhead cam engines allowed. No rotary engines . Cars may interchange with all gasoline engines and parts within same make under the following guidelines. With the exception of the dodge 2600 cc engine which is permitted.


No aftermarket blocks. No o-ringing of block of block to head allowed. Must use head gasket. Cylinder walls may be sleeved for repair. No excessive machining to fit parts from other models. All parts within the block must be of the same make.


May use any stock or aftermarket cast or forged piston. Must have same configuration as stock. Nissan 22 engine must use stock type dish pistons. Flat top pistons allowed only in engines that came that way. Toyota engines may use dome pistons which conform to all stock dimensions. Must match the head that is being used. Flat part of any piston may not protrude out of block. 0.065 inch max overbore permitted on all engines except for 3TC, where 59 mm is allowed. Pistons must be installed same as stock.


Any magnetic steel aftermarket rod permitted. No hollow rods. Maximum rod length 5.7 for Fords. Only Toyota engines may use H-Beam style rods.


Stock OEM crankshafts only. No aftermarket crankshafts. Crankshafts may be polished between #5 main and #4 rod journal only for viewing of possible cracks. Not for lightening. No machining to crankshafts except to journals. Lightening only to balance and by means of drilling, No grinding. OEM stock stroke crankshafts. 0.015 stroke variation from stock. May use later model 2.3 liter Ford crankshafts in early model 2.3 blocks.. No excessive machining to fit crankshaft to block. Crankshafts must be matched with there relative bore size. No 2500 cc crankshafts matched with a 2000 cc bore size. 3TC crankshafts allowed in 2TC blocks.


Any single camshaft permitted. Any lifter solid or hydraulic permitted. Aftermarket or high performance cam pulleys permitted. Stock ratio roller rocker arms permitted on GM engines only.


Only manufacturer stock production heads which bolt to engine block being used. No excessive machining to fit head to block. No aftermarket cylinder heads permitted.

NO Esslinger aluminum stock type reproduction heads permitted. Heads do not have to match the block but all parts must be from same make. No porting and polishing to head whatsoever. No blending of valve job with rotor tool to head casting. Bowl cuts will be in accordance with LMSC guidelines with no blending to port. Multi-angle valve job will be permitted.


Stainless steel valves permitted. Neck down valves permitted. Ford millimeter stern size valves permitted. Swirl polished valves permitted. Valve head diameter must match cylinder head being used, no oversized valves. Valves will be 1.75 or 1.5. Oversized valves add 100lbs to minimum weight. Listed right side and front minimum weight remains at 1035, total weigh 2400lbs.


Any valve spring allowed. Flat spring dampers allowed stock diameter.


350 cfm 2-barrell Holley carburetors teched. By LMSC guidelines.


A one piece or two inch aluminum carb spacer(s) (adapter) maximum 2 inches in thickness may be installed between intake manifold and carb. Any hole design and blending in spacer allowed. No more than 2 inches.


Stock and aftermarket intakes allowed. May machine port and polish stock intakes. Atermarket intakes must remain as from manufacturer, only machining to accept carburetor/spacer is allowed. Any gasket.


Any round pleated paper air cleaner no hats, ducts, o-baffles. Must not proturde through hood. No opening in hood or cowl. Hood must seal to fenders and cowl. Bottom of air cleaner cannot be above choke horn.


Only stock OEM starters permitted. Stock appearing for make and model block being used. No magnetos or MSD boxes. No crank-fire ignitions. Racing coils permitted. Mels ignitions permitted.


Must be 12V. The battery must be installed in an enclosed metal box complete with cover, located in front of the real axle housing or behind the driver's seat. The battery box must be mounted inside the frame rails and cannot extend below the bottom of the frame rails. The battery mounting position must be acceptable to Track Officials. Any battery that would be installed during the race must be installed in a battery box.


Any water pump belt driven from the crankshaft permitted. Stocked production radiators only or cheap aluminum racing radiator allowed. Minimum of one (1) quart overflow catch can required. All radiator overflow hoses must exit to the right side of windshield. Toyota may reroute water line to intake. Stock type or electric fans may be used stock type must have fan shroud over top of fan. Aftermarket pulleys permitted.


Must use stock lubrication system for block being used DEM or aftermarket oil pans permitted. No cranks scrapers/wipers. Windage trays permitted. No dry sump systems.


Any stock or aftermarket exhaust permitted. Must have pipe which exits side of car. Exhausts exiting thru the firewall allowed at tech officials discretion as to safety or arrangement. No header wrap allowed. Crankcase to exhaust evacuation system permitted.


Stock type clutch disc and pressure plate only, minimum 8.5 inches diameter disc. Aftermarket discs allowed must be OEM pressure plate and match block being used.


Aftermarket aluminum flywheels permitted, must be stock diameter for block used.


Blow proof bell housing recommended. If stock bell housing is used, a scatter shield of belt material must be installed to floor pan.


Must use standard OEM three (3), four (4) or five (5) speed manual transmission with all gears in working order. No automatics.


Only stock drive shaft permitted. Must be painted white. Two (2) 350 degree drive shaft loops of ¼ inch thick and two (2) inches wide solid steel required located six (6) inches to twelve (13) inches from each universal joint No aluminum drive shaft .


Must be stock, standard production assembly. May interchange makes and models. MUST use stock mounts for chassis being used and rear end must be in the stock position. Any differential allowed. No quick change rears allowed. Non-adjustable pan hard bars allowed. Must mount in stock location with stock brackets and bushings and must be mounted with the horizontal center line of the axle housing. Panhard bars on cars that did not come with them no adjustable pan hard bars. No independent rear axle assembles allowed. No cambered rear ends. Zero (0) degree camber with rear axle level.


No double master cylinder adjustable arrangements. Must be stock OEM parts. Flow control valves must be out of reach of driver.


Eight (8) inch maximum width permitted. Any offset allowed, must be same on all four wheels. Must be 13 inch wheel.


Track fuel required. $500.00 dollar fine for additives. Must purchase 10 gallons of fuel from track at each event. Minimum fuel cell capacity is eight (8) gallons. All fuel cells must meet the standard safety requirements and be incased in a minimum 24 gauge steel box. Electric fuel pumps permitted only when used with a Mercury cut off switch connected to the oil pressure switch . Fuel pump must be mounted in the engine compartment. No electric fuel pumps allowed in the trunk


All cars must weigh one (1) pound per cc. Minimum weight for any car is 2300 pounds. Minimum right side weight is 45% or 1035 lbs whichever is greater. All weight penalties are cumulative. Engine cc's must be posted on the hood in no less then 2 inch letters/numbers. Any weight penalties and infraction description must be clearly posted with engine cc's when crossing the scales after qualifying and race. Ex: Total weight: 2340 cc's.


Any questions call



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