I've got a question for those who know the history of these bikes better than I do. I recently found a youtube video of an early 90's evo and it sounded a bit different at idle then mine. (1999) I'll post the video if I can find it.

One of the comments said something along the lines of the evos had shovelhead technology in the bottom end up until 1992. Then something was changed resulting in a different running/sounding bike. I'm aware that the 1984 evo's had some of the remaining shovel parts in them but do later years up to 92 share similarities?

 

'' Listen to the Beautiful Sound Of this Motor, Sound Familiar ? That's the Sound Of A Shovelhead. The Early Case Breather Evo's Have The 1340 Shovel Bottom End. A completely different Bottom end Than 1993 and Later Head Breather Motors. You Are Able To Hear The Difference As Plain As Day. Had to call you on that one. Case Breather Evo, 1992 and and Earlier Is the Last of This Sound Due to the early 1340 Shovel Bottom end. 1993-1999 Sounds completely different.''

 

Up to '92 EVO's were case breathers.
After '92 they were head breathers.
'92 was the transition year and supposedly had some inserts that you could take out and make it a head breather.

 

thanks for clarifying

I should ask, does a evo with a head breather actually sound different from a case breather?

and what does he mean by 1992 and and Earlier Is the Last of This Sound Due to the early 1340 Shovel Bottom end.. Were shovels case breathers?

 

That idle sounds pretty low.

 

I agree. Sounds like it's on the verge of stalling out.

 

What changed was the flywheels, early evos still ran the heavier shovel type 42lbs flywheels, gave them that low loping idle everyone wants. Can't remember what year ( may have been 92) they went 20lbs lighter on the wheels so the idle had to go up, lighter wheels don't have the stored torque off the line the heavier do so you need a higher RPM to get things rolling. Lighter flywheel is why everybody thought the evos where so much faster, engines just spun up quicker.

 

84-85 Evos actually had cases that were shovel castings but machined for an evo top end..

I believe they changed the flywheels in 90...everything before that had a -78 part number

Disconnecting the voes switch will make an evo sound more like shovel than anything else.

 

The one thing that makes an EVO sound like a [better] Shovelhead... is Steel Cylinders..
Come to any Harley Drag, and See for yerself!!!!

 

I own a 92- april or may build i think?? Was a case breather only. Bottom rocker box spacer didnt have bosses for umbrella valves at all- and heads didnt have breather ports machined in at the air cleaner. So yeah- 92 was a mixed up year. Just my 2 cents.