1970 Olds Cutlass W31

1970 Olds W31 Launch at Sacramento Raceway
Photo By Bob Johnson 

The Car

Car:  An original 1970 Oldsmobile Cutlass S W-31
Front Suspension: Stock Olds except for Moroso front springs 250 lbs. in., QA1 RC1914P adjustable front shocks, removal of factory sway bar, modified bump stops, Moog ball joints, Timkin bearings, 7/16" x 3" Studs.
Rear Suspension: TRZ Adjustable lower control arms relocated to change IC, Chassisworks adj uppers, Pinion set at 2° angle, H&R parts 'n stuff rear chromoly sway bar set neutral, Moroso springs 125 lbs. in., QA1 DTC1661P double adjustable shocks, 1/2" x 3" studs
Steering: Stock W-31 except for GM Saginaw manual steering box to replace the power unit, Moog tie rod ends.
Brake System Front: Stock W-31 non power disc brake with Hawk pads.
Brake System Rear: Wilwood Disc with Wilwood pads and Kelsey Hays adjustable brake proportioning valve.
Safety Equipment: Simpson Camlock Belt, Jaz 12 gal fuel cell.
Instrument: Autometer Memory Tach w/Shiftlight. Autometer Pro Comp oil press and water temp gauge.

The Drivetrain

Transmission: FB Transmission Pro Comp Stage II Turbo 350 with JW Bellhousing, full manual reverse valve body with transbrake
Transmission Cooler: Perma-Cool  Maxi-Cool 6-pass with Fan
Torque Converter: JW 10" Ultra Comp #20444-A
Shifter: Turbo Action reverse pattern, Biondo air shifter, Biondo controller,
Driveshaft: Denny's Nitrous Ready 4.0" shaft with 1350 solid joints and TH-350 slip yoke.
Thirdmember: Strange iron 3.250" case
Spool: Strange lightened 35 spline
Pinion Support: Moser Daytona support
Gears: Motive Gear 4.86:1
Axles: Strange 35 spline
Wheels: 15" x 10" Centerline Convo-Pro rear w/5.0" backspace, 15" x 4" Centerline Convo-Pro front w1.750" backspace
Front tires: Moroso 7.10 x 15 - 27.750"
Rear tires: Mickey Thompson Radial Slicks 30x9x15  #3066R R1 Compound, screwed to rims, no tubes or Mickey Thompson Slick 30x9x15 #3066 L8 Compound Screwed to rims, no tubes.

The Engine

Year/Make: 1971 Oldsmobile
Bore & Stroke: 4.091" x 3.385" (103.91mm x 85.98mm)
Displacement: 356 ci, (5.83l, 5834cc)
Horsepower: Estimated 420 HP
Block: 1971 Olds 350 Gas Block w/stock caps and bolts
Crankshaft: 1971 Oldsmobile Nodular iron "N", Clevite MS 805P-10 bearings, .0034"-.0036" clearance.
Rods: 1971 Oldsmobile w/ARP bolts (50 lbs. ft.), beam polished and shotpeened, Clevite CB-684P-10 rod bearings, .0028"-.0030" clearance.
Pistons: TRW L2320F-030 Flat top (measure 4.0835"  .0075" Clearance),  Piston-to-Pin Clearance .0012", 11.76:1 compression (Compression changed from 11.38:1 to 11.76:1 in Feb 07). (changes: compression ratio increased to 12.4:1 9/09)
Rings: Total Seal plasma moly gapped .018" top, .020" second.
Oil System: AR modified Melling HD pump, Milodon Pickup, .345" Bypass Spacer, Milodon chromoly shaft,  Moroso steel 7quart oil pan, Directional windage screen, System 1 Oil filter, Angle milled block adaptor w/ bypass plugged,  Enlarged Oil feeds on upper main bearings, cam feed restrictors, 6 qts of Synergyn 3w30 Oil.
Heads: Oldsmobile #7 iron, milled approx .060"-.065" to 59-60cc chamber, ported, Exhaust crossover filled Feb 07. Update: heads milled to 56cc chamber 9/09
Valves: Intake Stock Length PEP 1.99" valves .0014" guide clearance, Valve face angle 45° x .049 seat w/30° backcut. Exhaust Stock length Manley 1.62" Exhaust valves .0024" guide clearance.  Valve face angle 45° x .059" seat w/top radius.  PC .500" seals.  Update: 2.07" / 1.68" stainless valves installed 9/09, all other specs remain the same
Rockers: Harland Sharp SV5002 Aluminum rollers
Springs: Crower 68101 Dual Tungsalloy 1.520" OD.  Installed 1.900" Installed height, 140 lbs seat pressure, 330 lbs. open Seat pressure changed from 130 lbs. to 140 lbs in Feb 07.
Retainers/Locks: Crower titanium / Crower +.050" 10° locks
Pushrods: Crower chromoly .083" x 8.450" long
Head Gaskets: Cometic MLS 4.100" x .036"
Camshaft: Cam Motion solid lifter, Duration @ .050" 238° Intake, 246° Exhaust, Lobe Lift .323" Intake, .3295" Exhaust, Valve Lift w/ 1.6:1 Rockers .517" Intake / .527" Exhaust, 109 LSA Installed 2.25° advanced, 106.75° Intake Centerline, Lash .022" Intake / .018" Exhaust.  Update: New camshaft installed on 9/09, Cam Motion solid lifter, Duration @ .050" 246° Intake, 257° Exhaust, Lobe Lift .348" Intake, .344" Exhaust, Valve Lift w/ 1.6:1 Rockers .557" Intake / .551" Exhaust, 109 LSA Installed 1.0° advanced, 108° Intake Centerline, Lash .022" Intake / .018" Exhaust
Lifters: Crower solid .842"
Cam Drive: Rollmaster Chain & Gears
Intake: AR Modified Holley Street Dominator.  Carb mounting flange welded and relocated.  Minor porting and port match. Modified SCE Intake Gaskets.
Carburetor: Box stock Holley 750 HP, custom floats, jet extensions, 1" tapered phenolic carb spacer.
Fuel System: Product Engineering 310 pump set @ 25 psi w/bypass, Barry Grant filter, and Product Engineering 4-port regulator set @ 7psi, Product Engineering regulator bypass and Earls braided line.  VP 110 racing fuel.
Ignition: MSD pro billet distributor w/advance locked out at 36 degrees, MSD 6AL-2 Programmable ignition Box, MSD 8.5mm Plug Wires and NGK B7S plugs gapped at .032"
Exhaust System: Kooks 1-7/8" Primary w/3" Collector, 12" collector extension, Pan Evac. (No Mufflers), SCE Reinforced Graphite Gaskets.
Cooling System: OPP Aluminum water pump, Moroso electric pump drive with AR built mount, Howe Aluminum radiator, Black Magic electric fan, 7/8" water restrictor.  Distilled water with 1/2 bottle of Red Line Water Wetter.
Balance Info: Bobweight 2217.1 grams, Piston: 644 gr, Pin: 130 gr, Rings: 61.5 gr, Locks: 0, Rod: 736 gr (Sm end: 195 gr, Bg end: 541 gr)

Car Setup

Weight Distribution: Car ready to race NO Driver: 3540 lbs

LF = 969 lbs. RF = 952 lbs. Front = 1921 lbs. 54.2%
LR = 769 lbs. RR = 850 lbs. Rear = 1619 lbs. 45.7%
Left = 1738 lbs. 49.0%, Right = 1802 lbs. 50.9%
Weight with Driver: Joe = 3735 lbs.

Front Suspension
Alignment: Camber: 1/4-1/2°: Positive, Caster: 2° Positive, Toe: 1/16" Toe In
Front Spring: 250 lbs. Spring Rate
Front Shocks Front (0-12 0=soft, 12=hard) Bump: Fixed Rebound: 4
Front Tire Pressure: 32 Psi Rear Suspension
Pinion Angle: 2°
Rear Control Arm: Lowest Position
Rear Spring: 125 lbs. spring rate
Rear Shock: Rear (0-24 0=soft, 24=hard) Bump: 4, Rebound: 0 or 1
Rear Tire Press: varies 15-18psi for Radial Slicks 11-13psi for Bias Ply Slicks    


Valve Lash: .022" Intake, .018" Exhaust Carburetor: Holley 750 HP
Primary Jet: 72
Secondary Jet: 82 (w/jet extensions)
Primary power valve: 65
Secondary power valve: None
Squirter (primary/secondary): 31 / 31
Pump Cam (primary/secondary): Red #1 / Red #1
Fuel Pressure (pump): 22 psi
Fuel Pressure (carb): 7.2 psi Ignition Spark Plugs: NGK B7S
Plug Gap .034"
Timing: 36° locked out Lubricants and Fluids Engine Oil: Synergyn 3w30 LTS
Transmission: Castrol Type F ATF
Rearend: Mobil 1 75w90
Wheel Bearing: Mobil 1 Synthetic
Coolant: Distilled water & 8oz Redline Water Wetter
Brake System: Wilwood DOT 3 570
Fuel: VP 110

Best Performance  

Best 1/8 ET:  7.423 by Joe Adkins on October 1, 2010 at Summit Div 7 ET Finals at Sacramento Raceway Park.
Best 1/4 ET:  11.731 by Joe Adkins on October 1, 2010 at Summit Div 7 ET Finals at Sacramento Raceway Park.
Best 1/8 MPH: 91.724 by Joe Adkins on October 1, 2010 at Summit Div 7 ET Finals at Sacramento Raceway Park.
Best 1/4 MPH: 113.18 by Joe Adkins on October 1, 2009 Summit Div 7 ET Finals at Firebird Raceway in Chandler Arizona
Best 60': 1.558 by Joe Adkins on October 30, 2009 at Barona Dragstrip, Lakeside California.