Cylinder Assembly
Before assembly, liberally coat all internal parts with a quality 20W-50 oil to prevent oil starvation at start-up and protect the moving parts until the oil pump supplies fresh lubricant. Do not use O-rings around the cylinder-to-head dowel holes. The Cometic head gasket has embossing around the dowel area and the dowel holes are smaller.
The head and base gasket surfaces of the Axtell cylinders are impeccably smooth, which is great because any imperfections on the gasket surface would cause failure with the high-tech MLS gaskets. Clean the head bolt threads and apply a coat of light machine oil to them and under the head bolt underside flange. This will give you accurate, uncompromised torque readings. Dirt and other resistance to threading in the bolts will alter the torque ratings. The two shorter head bolts are located on the spark plug side of the head, while the two long bolts are located on the pushrod side.
Alternatively snug the head bolts fingertight. In sequence, tighten the rear short bolt, then the front short bolt, then the rear long bolt, and, lastly, the front long bolt to 14 ft-lbs. In the same sequence, now tighten the four head bolts to 22 ft-lbs., then to 35 ft-lbs., and finally to 42 ft-lbs. Harley-Davidson recommends the same tightening sequence, but the oiling procedure substitutes H-D 20W-50 oil. The H-D procedure has you first torque the bolts to fingertight, then 120-144 in-lbs., then 15-17 ft-lbs. For the final torque, take a marker and mark the position of the bolt in relation to the head by making a washable line across the bolt head and onto the head surface. Now tighten the bolts, in the same sequence, a full quarter turn (90 degrees) more.
Start-up Tips
There are three major considerations for start-up: air/fuel ratio, ignition timing, and oil pressure. The air/fuel ratio must be rich. If you’re adding an aftermarket fuel modifier, it will probably be on the rich side, but always check. A lean air/fuel mixture leads to excess heat, which is especially injurious to new pistons and fitted cylinders. Leanness will lead to detonation. Though the CVO 110 is fuel-injected, carburetion settings for a new engine will add clarity to this subject. Install a larger, low-speed jet to provide more fuel at idle for cool running. Changing the main jet is not important at start-up because it controls fuel at highway speeds, which is beyond the rpm range for correct engine break-in. The bottom line is that a new performance engine requires fuel enrichment, if in doubt at all. Fuel cools the engine while air heats it up.
Advancing the spark ignition too much will also increase deadly heat. Start at 32 degrees when at full advance for initial start-up and tuning. There’s lots of time to dial in ignition timing and air/fuel ratio later on, but it’s paramount to begin in safe fuel and timing ranges.
Ensure there is oil pressure on startup. Axtell kits require at least 20 psi of oil pressure at 3000 rpm. Always check, but Twin Cams usually have around 35 psi at 2000 rpm.
Break-In
Do not believe the crowd that advocates full-tilt and boogie right out of the gate. Their attitude is that if the engine is no good, it will blow right away. If it holds together, it’s a good engine. All I have to say is bull! Any competent mechanic can disassemble an engine and read it to analyze why the engine self-destructed — say goodbye to the warranty! The proper procedure is to heat-cycle the engine by starting the motor with a heavy fan swathing cool air over the engine to dissipate heat. Initially, fire the engine and allow it to run for only 30 seconds. Then allow the engine to cool to room temperature. Restart the engine; allow it to run for 60 seconds; then let it cool down. Repeat this procedure adding 30 seconds each time until reaching a total of four minutes or 240 seconds or eight heat cycles. Change the oil and filter while the engine is hot. Cut the filter open to observe particulate matter, which will indicate any problems, as well as success. Once this is done, ride the bike for 1,000 miles, keeping the engine under 3500 rpm for the first 300 miles and less than 4000 rpm for the remainder. After this, still respect the engine until warm. Gradually increase rpm levels. Do not lug the engine or put undue stress on it, such as towing a trailer. In fact, never lug an engine, whether stock or performanced.
Conclusion
I’m taking no chances with Chris’ CVO 110. The two previous dealer rebuilds were ineffective. I’ve lowered the air/fuel ratio from the stoichiometric 14.7:1 to around 14.2:1 or lower, depending on circumstance with the input fuel modifier, Terminal Velocity. My close second choice for this application is the output fuel modifier Power Commander, which also has an ignition component unlike most of the other output modifiers. I chose Terminal Velocity because it’s self-tuning, based on real time O2 sensor information, and will adapt to changing conditions. There are many excellent fuel modifiers on the market and many not-so-good ones. Ignition and fuel modifier technology for Harley-Davidson is constantly changing. This is merely my current choice. A better system may come along next month.
The key is to have trust in a competent mechanic and abide by his decisions. If he cannot give comprehensive reasons for using a specific part over another, find a different adviser. I have spent much time analyzing the reasons for persistent and frequent CVO 110 rear head gasket oil leaks without a compression leak. It is obvious that cylinder redesign for the stock CVO 110 cylinders is a priority for the Motor Company, especially utilizing spiny lock, high-pressure, cast construction within the top cylinder deck, much the same as that found on the TC 88 workhorse cylinders. The metallurgy of the cylinder head’s gasket surface could also be upgraded so it will not warp under the heat the CVO must endure. The aftermarket serves the H-D rider well once again, as I was able to use the venerable Axtell cylinders and pistons to ensure, after the third rebuild, that Chris can ride problem free on his CVO 110.
Donny Petersen
Tattoo Tony’s Heavy Duty Cycles
Toronto, Canada
www.HeavyDutyCycles.com 
Techline-June09-H-D 110" CVO -Part VI: Ending thoughts and the wrap-up (concludes) 
Linear Mode
