For the valvetrain, a single valvespring with a damper was chosen. The 1.54-inch-diameter springs have a 1.90-inch installed height. They have 125 pounds of pressure at the seat, and are held in place by chrome moly retainers with heat-treated single slot keepers. | 
This top view of the assembled 351 Cleveland head clearly shows the splayed valve arrangement. The valves are neither in line nor are they perpendicular to the engine centerline. They're arranged for maximum flow potential in a hemispherical configuration. Completely dressed, the cylinder head weight is 32 pounds. |
This interesting comparison shot of the finished cylinder head and the bare casting shows just how much work has to go into the raw piece in order to create a working cylinder head. With the exhaust face showing, the generously sized ports can be seen. The slightly squared-off exhaust ports have the stock bolt pattern and are in the original location. The exhaust runner volume is 95 cc. | 
The combustion chamber volume here is a relatively small 60 cc, and when combined with the large 2.05-inch intake valves, there's not a lot of room left over. The valve seats are made of hardened ductile iron for use with unleaded fuel. |
The question soon arose about what awaits the person who wants to try these Cleveland heads on a Windsor block. This photo shows how the castings are prepared for this possibility. The large cooling passage on the combustion face (shown on the left) will be threaded in the production head, and plugs will be furnished. The small dimple seen on the intake face of the cylinder head denotes the spot where drilling should be done to open up the water passageway for use on the Windsor engine. With the threaded plug in place and the other passageway opened up, the quest for an intake manifold can begin. We've even heard rumblings at Edelbrock that production of a Clevor-type intake might be in the cards for the near future. | 
The numbers for this graph were obtained with a 377ci Cleveland Ford engine. It was bored 0.040-inch over and equipped with a 3.700-inch stroke crankshaft. A connecting rod with a 6.00-inch center-to-center length was used. The compression ratio on the engine was 9.7:1 and a 750-cfm carburetor was installed on top of an Edelbrock RPM 351C Air Gap intake. The camshaft used had a duration at .050 of 234 degrees intake and 244 degrees exhaust. Lobe lift for the cam on intake was .325 and .340 on exhaust. Lift at the valve worked out to .562 intake and .588 exhaust, and lobe separation was 112 degrees. |
| Edelbrock Cylinder Head Dyno Results | | RPM | HP | TORQUE |
|---|
| 2,500 | 174.9 | 367.3 |
| 3,000 | 224.5 | 383.1 |
| 3,500 | 255.7 | 393.8 |
| 4,000 | 335.4 | 440.3 |
| 4,500 | 381.7 | 445.4 |
| 5,000 | 414.7 | 435.6 |
| 5,500 | 441.5 | 421.6 |
| 6,000 | 456.2 | 399.3 |
| 6,500 | 454.8 | 367.5 |
|
The goal to create a 450-plus-horsepower package for the Cleveland Ford has clearly succeeded, and this figure will no doubt be surpassed as larger power-making components are added to the equation. The Edelbrock aluminum cylinder head for the Ford 351 Cleveland engine should be available at a competitive retail price (to be announced) by the time you read this.