2912cc bored 30 thou over giving a displacement of 2963cc (180.8ci).
Compression ratio is 12:1 using Venolia domed Pistons and Total Seal Gapless rings.
Cranking pressure is 240psi give or take 2-3psi across all cylinders.
Leakdown is under 1%.
Horsepower is approximately 200hp, with a 5500RPM redline, although if pushed hard we'll sneak it on up to 6000.
No fancy aluminum head, billet crank or Carillo rods - hence the RPM limits. Maxed out my Visa Card years ago!
Lightweight steel flywheel - 14 lbs. using a 9 1/2" competition clutch.
Cam specs: 300o duration, with a cam lift of 0.315". Using the stock lifters and stock rockers with a 1.43 ratio with a valve lift is 0.40505". Valves are 214N stainless steel with stellite tips with competition springs.
Added an adjustable cam timing gear (from Denis Welch of course).
We run the engine timing a tad over 40o BTDC, and use 110 octane race fuel.
An aluminum ribbed baffled sump keeps most of the oil in the engine.
We run Valvoline 40 weight racing oil that seems to be working pretty good.
We tried the vane type oil pump, but noticed that it put quite a load on the cam gear and caused premature wear. We went back to the stock gear pump and record an oil pressure of 35-40# running hard in 100o Texas heat.
We use a 16 row oil cooler up front to control the oil temperature reasonably well. The hottest oil temperature we've seen is about 220o (again running hard in 100o Texas heat).
The radiator is aluminum with an 1600cfm electric fan (used during pace laps and cool down laps). No fan on the water pump. We manually switch the fan on or off as required. Water temp holds at 190o and occasionally may move up to 200o in real hot weather. We use a stock 190o thermostat.
Solid aluminum engine mounts are used per the works cars thus making the engine a part of the frame.
Carbs are triple Webers DCOE40s running through special manifolds. The only reason for using DCOE40s as opposed to '45s' is that we got a great deal on the '40s'. We admit it - we're cheap!
Custom headers with a side exhaust manage to cause hearing loss within 50'. The powder coated feed 2 short side exit 2" exhausts - it's loud! Even with ear plugs I now have to wear bloody expensive hearing aids!
A Tilton high torque starter motor means we always start on pre-grid - even with a hot engine. Sounds like a Cessna starting up tho'.
Added a 2nd oil breather line from the valve cover back to a push rod cover to minimize any pressure build up in the engine.
Replaced the crankshaft damper with a competition after market unit.
We found that using a Mallory dual-point distributor gave us the best ignition results and still look and be vintage legal.
Replaced the horizontal brace in front of the engine with a removable piece of steel bar to facilitate removing the cam, and timing chain without having to pull the engine.
We also use a Denis Welch rear main oil seal that helps to keep most of the oil in the engine. Works pretty good.
We use an old racing trick to identify the spark plug wires. We use small cable ties (1 for cylinder #1, 2 for #2, etc). That way we can pull the wires at will and never worry about getting them mixed up when reconnecting them. We also painted a small black vertical line on the distributor cap corresponding to cylinder #1.
Competition NOS lever shocks are used fore and aft, and are coupled with 600# coil springs up front.
Competition leaf springs are used in the rear.
A 7/8" anti-sway bar up front and a 5/8" anti-sway bar in the rear along with the stock rear panhard bar keeps everything pretty level under hard cornering.
Grade 8 bolts have replaced the stock front antisway bar bolts. the stock units just couldn't take the stress.
The rear Panhard rod uses nylon bushings, and the mounts (especially on the port side rear axle have been significantly beefed up).
Off-set delrin bushings coupled with some shock adjustments are used in the front shocks to give a 1 1/2o negative camber on the front wheels.
Anti-tramp bars are mounted under the rear leaf springs to control axle wind-up.
The car has been lowered 2" up front and 1" in the rear to improve high speed stability.
Wheels are 15" x 5.5" 72 spoke wire wheels. Currently we're running 205/60 -15 Hoosier Speedsters. They stick real good and are somewhat affordable (approx $160 each) - generally lasting 3-4 events. Tried the Dunlop bias ply race tires - a real blast to drive on but the tires were finished at the end of a weekend.
A 5/16" spacer is used on the rear wheels between the hub and the brake drum to give the necessary clearance between the tires and fender wells. Even with the car being lower than stock, the clearance is sufficient between the tire and the fender edges, primarily because of the low body roll.
Brakes are BJ8 calipers up front with stock Alfin drums in the rear using Hawk HT-10 linings.
Dual girling master cylinders are used for the brakes - a 3/4" for the front and a 5/8" for the rear. The front master cylinder feeds a Lockheed brake servo and the rear goes through a proportioning valve to adjust fore and aft brake forces.
A custom pedal box was built to connect the master cylinders to the brake and clutch pedal.
A stock unit with straight-cut gears using the Sebring Ratios:
1st gear 2.413 2nd gear 1.722 3rd gear 1.255 4th gear 1 overdrive on 3rd & 4th 28%