Copyright © Rotorway-Rework. All rights reserved.
I debated for quite a while as to whether I should install a cog drive and which one AP or Pro-Drive. After researching both designs I felt the AP drive was the better unit. Locating one was a story in itself! I ended up purchasing one that I had previously passed on in Canada only to pay more for it a year later in New Hampshire.
1. This shows the new 35MM secondary and the previously installed AP cog system as delivered. The large sprocket replaces the chain sprocket. Very important to get the four attaching bolt holes aligned and drilled with a "D" drill for snugness. These bolts get safetied after torqueing. This cog eliminates oil leakage issues from the chain lubricating oil bath tub. Also visual inspections are better without the tub blocking your view of critical areas.
2. Alignment is everything for this setup and should not be rushed. Notice how open everything is without the tub. Al supplies very good instructions with this kit, however, there are no pictures. You would do well to visit someone with this installation or ask for some pictures from builders to get an overview of the project. Do not use a stretcher like with the Pro-Drive system to tighten the cog belt, it is not necessary for this cog belt to be that tight!
3. One issue that I encountered was that once I had the cog aligned my alternator/water pump belt wasn't adjustable. I had to either slide the secondary over or try a different alternator belt. To keep things as standard as possible I opted to re-adjust the secondary. Problem solved! Remember that after the secondary is aligned up or down you need to verify that alternator/pump height is aligned to the secondary pulley.
4. This is the AP tensioner mechanism. It is powered from a "T" on the engine oil system near the filter. This idler maintains a consistent pressure against the cog belt insuring that the cogs stay engaged with their sprockets. This is one of the major differences between the AP and Pro-Drive systems. Theoretically this will prevent undo stress and flexing of the cantilevered secondary upper shaft. Time will tell. The factory has made this system standard on their new Talon and provides retro-fittable systems for the fleet. Al B now provides a residual restrictor valve that prevents oil from returning to the sump after shutdown from the tensioner. This system can be replaced by the current OEM spring tensioner. The spring tensioner system prevents potential oil leaks from units installed above the belts.
5. This is the new RWI COG large sprocket made from billet. It is eight pounds lighter than the original spoked cast style.
6. Here is the current RWI spring tensioner which replaces the original oil driven unit. This can be retrofitted to previous cog system installations. The main advantage is there is no chance of an oil leak.