Twin Cam Hop-Up

10. John applied a B-Grit medium/finelapping compound to the outer part of the new valve. The lapping compound is made up of tiny pieces of carbide mixed with grease to act as a fine-tuning solution to get rid of any high spots on the seat, so the new valve and valve seat mate perfectly. Before lapping, the valve seat is covered with a blue "marking" solution to let John know after a few turns with the lapping tool if there are any high spots he'll need to grind down with a stellite-tip stone before final valve installation. If blue spots remain on the valve seat, they will be grinded down. The valve and the seat should mate perfectly-when the valve is closed, it's completely sealed!
10. John applied a B-Grit medium/finelapping compound to the outer part of the new valve.
11. John checked the clearances of the valve to the seat that were marked with blue and grinded it down with the stellite tip. On the milling machine, the seats were milled in a three-tiered angle milling process, starting from the top of the seat to the inside of the seat. The top tier was milled at 30 degrees, the middle tier at 45 degrees, and finally the inside tier at 60 degrees. This also helps fit the new valve. Once this was finished, the lapping process was repeated. Once he'd finished, it was time for the final installation of the valves.
11. John checked the clearances of the valve to the seat that were marked with blue and gr
12. With the Viton oil seals in place, John installed the new valves and valve springs with a spring compressing tool. Then the valve springs were compressed and the valve keepers were installed. Presto, the Branch-O'Keefe process was finished. Now it was time to install the new heads on the Street Glide.
12. With the Viton oil seals in place, John installed the new valves and valve springs wit

13. We checked in with Eric Bennett to see how he was coming with removing all of the necessary components for the install. He had already propped up the tank so it was out of the way and had taken off the air filter and backingplate, removed the rocker box covers, breather element, stock pushrods, lifters and rocker boxes, and was just about ready to remove the old heads with the exhaust system still in tact. This guy is efficient.
13. We checked in with Eric Bennett to see how he was coming with removing all of the nece
14. Next, he removed the cam cover to take the stock cams out.
15. He removed the cam plate and snap ring and pulled the inner cam bearings. The new Torrington cam bearing (shown here on the left, sold separately) provides more surface area contacting the cams than the stock cam bearings. Side Note: Before installing cams into the cam plate, you should dry fit the cams to check lobe to case clearance. Check both cams, and if they spin then you're good to go.
15. He removed the cam plate and snap ring and pulled the inner cam bearings. The new Torr

16. Eric checked the lobe to case clearance and installed the Andrews 54H cams into the cam plate and back into the case.
16. Eric checked the lobe to case clearance and installed the Andrews 54H cams into the ca
17. The piston eyebrows (valve pockets) needed to be grinded down to compensate for the larger valves in the Branch-O'Keefe heads.
17. The piston eyebrows (valve pockets) needed to be grinded down to compensate for the la
18. It was time for the new heads to be installed. Eric placed the Cometic head gaskets on the cylinders and the Branch-O'Keefe heads slipped into place. Eric put anti-seize on the threads of the head bolts and tightened the heads down to factory spec. Then he started with the rocker box assembly.
18. It was time for the new heads to be installed. Eric placed the Cometic head gaskets on

19. Eric placed the new Cometic filter into the breather system and reinstalled it into the rocker boxes. He made sure to put Loctite onto the threads of the breather bolts before reinstalling. Then he tightened down the rocker boxes to factory spec.
19. Eric placed the new Cometic filter into the breather system and reinstalled it into th
20. Next, he installed the pushrods and pushrod tubes.
21. Then he reinstalled the rocker box covers in a criss-cross pattern to factory spec, and re-installed the Vance & Hines Pro Pipe back in place. Once all of the components of the motor were back where they needed to be, Eric moved on to final assembly.
21. Then he reinstalled the rocker box covers in a criss-cross pattern to factory spec, an

22. When we baselined the bike on the dyno we reached 74.13hp and 91.39 lb-ft of torque. Keep in mind that the base number was not stock. The Street Glide already had some performance gains from the Doherty air cleaner and the Vance and Hines Pro Pipe, which were previously installed before we got our hands on the bike. After installing the Branch-O'Keefeheads, Andrews Cams, and Screamin' Eagle pushrods, we immediately put the bike back on the dyno and increased to84.91hp and 94.61 lb-ft of torque. But we weren't quite finished yet. We wanted to give the bike back to the owner to put some miles on the bike with the new heads and cams installed. He put about 300 miles on the bike and gave it back so that we could dyno it again. Here you can see the end results: strong torque numbers right out of the hole and continuing up into the 4,000 rpm range. The hp was very smooth, and steadily increased well into the higher rpms. The owner stated that the bike is much more fun to ride, especially jamming around the city. Even at highway speeds, here's plenty of muscle to get around slower-moving vehicles quickly and easily. We reached a slight gain in power at 88.14hp and 97.62 lb-ft oftorque. But check out the air/fuel ratio...

23 & 24. The Thunder Max is a closed loop replacement system for stock EFI closed loop systems (it can also replace stock open loop systems if exhaust pipes are fitted with O2 sensor bungs). It automatically tunes itself as you ride when modifications are made. Focus on the air/fuel ratio of this chart. An optimal air/fuel ratio is approximately 13.5 to 13.7 parts of air per 1 part of fuel. After the bike owner put a little over 300 miles on the bike and we dyno'ed it, notice how the blue line runs in that 13.5 to 13.7 range, which helps improve fuel mileage efficiency and overall performance. This more optimal performance stayed pretty consistent, never going above 14 parts of air per 1 part of fuel.