Milodon manufactures gear drives designed for high-performance engine applications. These drives offer precise cam timing and durability, intended for use in competition and racing engines. Several models are available, catering to different engine types and configurations. This article details the installation procedures and model variations based on available documentation.
Model Overview
Milodon produces multiple gear drive models, categorized by their intended application and engine compatibility. Documentation identifies three primary models: Super Stock, Unblown Competition, and Supercharged Engine. The Super Stock model is designed to fit under stock water pumps. The Unblown Competition model includes a fuel pump drive and adapter plate. The Supercharged Engine model incorporates a fuel pump extension and drive. These drives are compatible with 302-460 Ford, 340-360 Small Block Chrysler, Pontiac, Olds, and AMC engines, as well as Small Block Chevy, Big Block Chevy, and Big Block Chrysler (Wedge & Hemi) engines.
General Installation Procedures
Installation procedures share common steps across different models. The process begins with removing existing timing components. Users must remove the stock timing cover, chain, and gears. Preparation of the engine block’s front surface is crucial, requiring deburring and cleaning to ensure a smooth mounting surface. Specific attention should be paid to removing stock dowel pins from the block.
Component Installation
The installation process involves assembling and mounting several key components. A three-piece roller bearing assembly, consisting of washers and a bearing, is placed on the camshaft. A hub is then secured to the cam with Allen bolts. The cam gear is subsequently installed onto the cam hub. The crankshaft gear is also installed, with the chamfered side facing the engine.
Mounting Plate and Gear Alignment
A mounting plate is loosely installed using the stock cam retainer bolt holes. The idler gear’s position is critical for proper alignment and backlash adjustment. A specific technique utilizing newsprint is recommended for centering the idler gear and setting the lash between all three gears. A strip of newsprint, approximately 1/2 inch wide and 6 inches long, is wrapped around the idler gear, positioned between the cam gear, idler gear, and crank gear. The mounting plate and idler gear assembly are then pressed firmly toward the cam and crank gears while ensuring the newsprint remains in place.
Final Assembly and Adjustment
After the newsprint method is used to center the idler gear, the mounting plate cover bolts are tightened. The center removable cover plate can then be removed. The gear drive is rotated to remove the newsprint, and smooth rotation is verified. Following this, the block is drilled and reamed through the front cover drill bushings. Hardened drill bushings remain in the cover permanently. Dowel pins are installed into the block, with the larger end inserted into the block itself. This allows for reinstallation of the gear drive without requiring additional adjustment, maintaining consistent cam timing.
Cam Thrust Clearance Adjustment
For Unblown and Supercharged gear drives, cam thrust clearance adjustment is necessary. These models utilize a silver laminated shim washer placed on the cam hub between the secondary cover and the cam hub bearing register. The end play must be maintained between .000 and .005 inches, achieved by peeling apart the shim washer in .003-inch increments.
Ford Engine Specific Considerations
For Ford engines (specifically models 14200 and 14600), the Milodon cam hub is double drilled to prevent shearing of the single factory dowel. It is recommended that high-end applications utilize a double-doweled cam to match this hub. The hub features a seven-bolt veneer pattern, allowing for flexible bolt location during installation.
Importance of Accurate Installation
The documentation emphasizes the importance of correctly following the installation instructions. Proper installation ensures accurate cam timing and optimal performance. The newsprint method is highlighted as a superior method for establishing proper gear clearance compared to using a dial indicator, as it addresses multiple procedures simultaneously.
Conclusion
Milodon gear drives provide a robust and accurate solution for cam timing in high-performance engines. Successful installation requires careful adherence to the provided instructions, including proper component preparation, alignment, and adjustment. The specific model chosen should align with the engine type and intended application. Maintaining correct cam thrust clearance, particularly in Unblown and Supercharged models, is essential for optimal operation. The double-dowel feature on Ford engine hubs enhances durability in demanding applications.