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[Kingspoke]

true,I also missed that it was a 110.on ANY 110,stock or not.ide replace the OEM springs with AV&V beehives.WAY more than needed pressure for most cams with the OEM/SE springs

So what has been the effect/results of using stock 110 springs on a 110 stock motor.  Have you had failures directly related to stock springs on stock heads? 

Seems a bit much in expense just for a cam change, but I'm not the expert.  The warrantied SE 117 kit (.579 lift) utilizes the stock heads, also.

Not trying to challenge your expertise, I'm certain you forgot more than I know about these motors.

[Lprez]

Update:
After completely overthinking the issue, I took a different path (and sorry, no dyno results).  I decided to stay with the stock 255 cams and stay out of the engine.  I wasn't convinced the 585 cams would be that much different than the 255s. A local indy installed the D&D 2:1 Fat Cats and changed out the primary to a 31 tooth.  Words cannot adequately express the performance boost the bike got from these changes.  Low end torque dramatically improved and the roll on throttle up to 4,000 RPM is so much better.  I'm using the fuel map for the Fullsac DX pipes and it's popping a bit on decal, so I'm going to ask TTS if they have a map for new the exhaust/intake set up.  Otherwise, off to a tuner.   Before tuning, these upgrades total ~$1,700.  If you want a relatively low cost upgrade and huge bang for the buck, consider this setup!

[Kingspoke]

255's are hard to beat for low end grunt!  I've heard a lot of guys going to a 30 tooth sprocket, and love the results.  Have fun with the grunt!

[grc]

So what has been the effect/results of using stock 110 springs on a 110 stock motor.  Have you had failures directly related to stock springs on stock heads? 

Seems a bit much in expense just for a cam change, but I'm not the expert.  The warrantied SE 117 kit (.579 lift) utilizes the stock heads, also.

Not trying to challenge your expertise, I'm certain you forgot more than I know about these motors.

I know this wasn't directed at me, but I'll throw out what I know about the subject until one of the experts chimes in.  For reasons known only to Harley, they have always used dual (inner and outer) style valve springs on the CVO engines.  The inner/outer spring design helps dampen vibrations in the valve train, but modern beehive designs also do that thru the variable pitch of the spring.  I'm not sure even the folks at Harley could tell you why they still cling to the old design.  Either design can work well, so that isn't the issue.  The issue as I understand it is that they specified springs that are too strong for the engine, which adds to the stresses placed on everything from the valves all the way to the lifters and cams.  All you need is enough pressure to keep the valves from floating at the highest rpms the engine is expected so see, with a small safety margin of course.  Yes they used large heavy valves (light valves cost more), but they aren't heavy enough, and the engines don't turn fast enough, to justify the spring pressures Harley used.  Many builders have indicated they used lighter beehive springs without creating issues with valve control.

JMHO - Jerry

[prodrag1320]

So what has been the effect/results of using stock 110 springs on a 110 stock motor.  Have you had failures directly related to stock springs on stock heads? 

Seems a bit much in expense just for a cam change, but I'm not the expert.  The warrantied SE 117 kit (.579 lift) utilizes the stock heads, also.

Not trying to challenge your expertise, I'm certain you forgot more than I know about these motors.
[/quot


Most lifter failures in 110 motors can be traced back to too much spring pressure from the SE springs.we've had 0 failures in motors that we've done

[HD Street Performance]

I know this wasn't directed at me, but I'll throw out what I know about the subject until one of the experts chimes in.  For reasons known only to Harley, they have always used dual (inner and outer) style valve springs on the CVO engines.  The inner/outer spring design helps dampen vibrations in the valve train, but modern beehive designs also do that thru the variable pitch of the spring.  I'm not sure even the folks at Harley could tell you why they still cling to the old design.  Either design can work well, so that isn't the issue.  The issue as I understand it is that they specified springs that are too strong for the engine, which adds to the stresses placed on everything from the valves all the way to the lifters and cams.  All you need is enough pressure to keep the valves from floating at the highest rpms the engine is expected so see, with a small safety margin of course.  Yes they used large heavy valves (light valves cost more), but they aren't heavy enough, and the engines don't turn fast enough, to justify the spring pressures Harley used.  Many builders have indicated they used lighter beehive springs without creating issues with valve control.

JMHO - Jerry

A perfect description nothing to add except the origin of the dual springs started as far back as the EVO Screaming Eagle performance heads, carried over to the SE MCR performance heads and then on to the CVO110. The springs used on the MVA heads are higher rate than the stock CVO duals. The beehives control harmonics better by design therefore even with the heavy valves the high spring pressure is not needed. Conical springs better yet.

[Kingspoke]

Thanks all!  Very informative. 

Moco obviously has not felt a need to change the springs, for whatever reason(s), being that they warranty their performance kits/cam kits with no recommendation to change the springs, so perhaps the costs/failures on their part is negligible.  Whereas in the cam bearings they did change to their full compliment bearings in 2013 & recommend SE bearings on all non OEM cams.