ACR's
#1
ACR's
I own a 2008 Ultra with a Stage 2 kit installed. I've gone though a few starters and have been considering installing ACR's. I had a SE compensating gear installed as well but it hasn't totally resolved the issue. Has anyone had this installed done on a similar set-up and what do you think of the results?
#2
Are you looking at automatic compression release (ACR) or manual compression release (MCR)? ACR's will need a threaded port machined into the top of your heads under the rocker boxes along with a wiring harness instal and possible adjustments to your ECM depending on how you want them controlled. MCR's will require a threaded port machined in the heads next to the spark plug ports. MCR's are pushed in before starting and will close when the bike starts. I'm no expert on this but I was looking into it myself. I just did work to my wife's bike and I installed heads from a 2014 Street Glide that had the ports for ACR's in them so I could add automatic compression release.
#5
I have acrs on a 107 build. It definitely made a huge difference on starter wear and tear. The cost of the actual acr isnt as much of an issue as the more complicated machining. The pita portion of the install is wiring the harness. Well worth the trouble in my opinion. They're hidden and actuate everytime you start the bike.
#6
The following users liked this post:
kingdeuce2 (03-09-2023)
#7
Trending Topics
#8
My other engine is a S&S 106 that has a used set of 2012 heads with ACR's port and polished for my build. I didn't think wiring was difficult at all and my power vision turned them on.
The following users liked this post:
kingdeuce2 (03-09-2023)
#9
Many/most Stage II kits come with the SE-255 cams which contribute to "hot start" problems ... Installing ACR's in your heads require specific machining tools ( which are quite expensive ) and a qualified machinist. Manual compression releases are a fairly straight forward installation and are quite simple to use. The other option is to swap heads with a set of later model ACR heads. There is a harness required to complete the installation and then the "flashing" of the ECM to turn them on. As mentioned earlier a Power Vision can do this. Also you can wire the ACR's through the "start circuit" and avoid/eliminate the optional harness.
http://www.harley-davidson.com/app-c...ts/-J04210.PDF
http://www.harley-davidson.com/app-c...ts/-J04210.PDF
Thread
Thread Starter
Forum
Replies
Last Post