why is Twin Cam better than an Evo?
#1
#2
First let me preface this by saying, I am not an engineer. Nor do I have access to anybody at H-D to explain to me their thinking. Most of what I may or may not know is probably totally erroneous. I'm just another know-it-all internet schlub.
The Twin Cam geometry allowed Harley to straighten out the pushrod angles to each cylinder. This makes for a more efficient valve train geometry.
While they were at it, they removed the outer cam support from the cam cover. This was done to make the engine quieter. Since the cam cover is now just a cover, it doesn't transmit as much noise. Same thing as when they went from the Shovelhead to the Evo. Then they removed the rocker arm shafts from the rocker boxes.
The Twin Cam engines also have a gerotor oil pump, vs. a simple gear pump on the Evo's. Again this is for efficiency, the gerotor pumps more volume. There are also oil jets squirting up under the pistons that are to cool the head of the pistons.
I'm missing a bunch of stuff, no doubt. But I'm also sure somebody else will come along and fill in the gaps and let you know where I'm totally off base. :-D
The Twin Cam geometry allowed Harley to straighten out the pushrod angles to each cylinder. This makes for a more efficient valve train geometry.
While they were at it, they removed the outer cam support from the cam cover. This was done to make the engine quieter. Since the cam cover is now just a cover, it doesn't transmit as much noise. Same thing as when they went from the Shovelhead to the Evo. Then they removed the rocker arm shafts from the rocker boxes.
The Twin Cam engines also have a gerotor oil pump, vs. a simple gear pump on the Evo's. Again this is for efficiency, the gerotor pumps more volume. There are also oil jets squirting up under the pistons that are to cool the head of the pistons.
I'm missing a bunch of stuff, no doubt. But I'm also sure somebody else will come along and fill in the gaps and let you know where I'm totally off base. :-D
#3
I have a 2010 Dyna with the 96" and 6 speed.
I also have a 94 FXR with a healthy Evo.
They both have their advantages. And disadvantages.
My TwinCam is fuel injected, and has a 6th gear. Definite plus.
Th Evo is certainly more fun, doesn't run as hot, and I trust it more. Oh yeah, and my "little 80in Evo" stays right on my buddies CVO 110 Dyna without a problem, even when he gets the jump.
I think it will come down to preference.
When cruising, they're close, with the FXR winning out in smoothness due to a better design. But, the engines overall no real difference in vibration.
Disadvantage with my Evo, 94 cases are suspect, and I if I want to go bigger, I'll end up with a crate engine.
TwinCam, well, that will depend on the year. All in all, go with what you like, and what you're comfortable with.
Overall, I'm no engineer either, so... YMMV
Chase
Last edited by Chasespeed; 08-24-2014 at 08:18 PM.
#5
It's neither better or worse....It's just different in some ways.
I like my TC motors and I always liked my EVO's too.
I no longer have any EVO's, but who knows? Maybe someday I'll get one again.
I'm a little disappointed with the quality of the motors in the last few years....Harley seems to be cheaping them down a little too much.
I like my TC motors and I always liked my EVO's too.
I no longer have any EVO's, but who knows? Maybe someday I'll get one again.
I'm a little disappointed with the quality of the motors in the last few years....Harley seems to be cheaping them down a little too much.
#6
the evos have gear cams . twin cams chain driven cams. evos have no cam chain tensioners to mess with. I love my twin cam dyna but do not like the sloppy crankshaft runout on the new motors and I hate having to check the cam tensioners every 20 K or so to see if they are ok. I think twin cams require more attention to maintain . That may just be me. Took me forever to figure out if I liked EFI instead of a carbed bike.
#7
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