With thousands of hours of thought and analysis, hundreds of hours of hard work, and four hours of testing, the Robinsons packed up their unlikely creation and headed from Grimsby, Ontario, Canada, down to the Jegs Engine Masters Challenge at the University of Northwestern Ohio campus in Lima, Ohio. When their time slot finally came, they hooked up their stock cast-iron headed 307 to the DTS dyno, while the crowd watched the closed-circuit TV in the main EMC lounge area. They didn't know that they were about to get their socks blown off. Where big-name engine builders broke or were DQ'd, the little Olds kept on. Where some ran hot and saw their scores shrink, the Robinsons kept making power, not dropping a point between their three final pulls. With over 435 hp and 430 lb-ft of torque from a tiny mid-'80s smog engine, the guys from up north proved that their analytical skills and attention to detail put them square in the middle of some of the best engine builders in the country.
The Ross custom pistons were...
The Ross custom pistons were built with plenty of clearance to allow for cam changes. Tight lobe separation, not total lift, is a critical factor when it comes to determining the valve notch depth. Fortunately, there was no indication that piston-to-valve contact occurred. Thanks to a perfect crank-polishing job, the Mahle-Clevite coated bearings look just like new even after making 435 horses on a light 40 psi of oil pressure.
Using every trick in the book,...
Using every trick in the book, the Robinsons used a heat shield under the valley pan to keep hot oil from splashing up onto the valley pan and heating up the incoming charge.
Dribble holes provide much-needed...
Dribble holes provide much-needed lubrication to the solid flat-tappet cam as the spring pressure could easily flatten a dry lobe.
|BY THE NUMBERS |
|ROBINSON ANALYTICAL 307CI OLDS |
|Bore: ||3.855 inches |
|Stroke: ||3.384 inches |
|Displacement: ||316 actual cubic inches |
|Compression ratio: ||10.4:1 |
|Camshaft: ||COMP solid flat tappet |
|Cam duration: ||235/239 degrees |
| ||at .050-inch tappet rise |
|Valve lift: ||.633-/.592 inch |
|Rocker ratio: ||T&D Shaft |
| ||1.8 intake/1.65 exhaust ratio |
|Top ring: ||1mm, CP Pistons |
|Second ring: ||1.2mm, CP Pistons |
|Oil ring: ||2mm, CP Pistons |
|Piston: ||Ross dome |
|Block: ||OEM cast iron |
|Crankshaft: ||OEM forged 330 Olds |
|Rods: ||Eagle 6.25-inch featherweight |
|Cylinder head: ||OEM 5A cast iron |
|Intake valve diameter: ||2.02 inches |
|Exhaust valve diameter: ||1.55 inches |
|Intake manifold: ||Edelbrock Performer RPM |
|Carburetor: ||Edelbrock 800 Thunder AVS |
|Header: ||Hooker 1 5/8-inch primary |
|Ignition: ||MSD Streetfire |
|Engine oil: ||Royal Purple 5W30 |
|Mufflers: ||MagnaFlow |