http://www.revzilla.com/common-tread/exclusive-leaked-pictures-of-the-new-harley-107-milwaukee-eight-engine?utm_source=facebook&utm_medium=social&utm_campaign=boosted-posts%7Ctpfn&utm_content=common-tread-news&utm_term=exclusive-leaked-pictures-of-the-new-harley-107-milwaukee-eight-engine-post-072516-%7CtpfnMILWAUKEE EIGHT
I was doing my usual “Monday-morning-man-I-need-coffee” thing, and then a bomb dropped in my lap.
A different source than the one identified in my previous article on the new Harley drivetrain got in touch and said he “wanted to put some rumors to rest.” I'm all for that. Let's do it.
What followed was a ridiculously in-depth breakdown of what’s coming down the line from Harley-Davidson. This source is not an employee of the Mothership. Instead, my informant is employed by an independent test facility. I’m going to relay everything I got to you, Dear Readers. Same disclaimer as last time: No guarantees, but everything I heard lines up with suspicions and rumors and makes sense.
[Right side of the engine
Here's the right side. Cam cover looks a little different, doesn't it? There's actually two pushrods per jug, you just can't see 'em. Source photo.]
In addition to the photos, my informant provided a ridiculous amount of information about the engine. (A well-educated Deep Throat is the best kind.) First, displacement of 107 cubic inches is confirmed, as thought, and the Milwaukee Eight moniker we chatted about in the comments of the other article is also confirmed by our source. Additionally, I’m told a 114-inch variant will be coming as well, and there is talk of a 131-inch permutation. For 2017, we are only going to see this in the Touring bikes. By 2018, however, the new engine will be going into all the Big Twin models. These new engines are a single-cam design but have four-valve heads. The cam is chain-driven, presumably to keep the EPA happy about engine noise, and the valves are operated by a forked rocker.
“It’s sort of half-Evo, half Twin-Cam,” I was told. These engines are set up to have the heads both oil- and water-cooled. Oil feeds from the rear rocker box up to the front.
“Just like a Shovel!” I exclaimed.
“They feel different than a Harley. They’re very well balanced, very smooth,” I was told. “They definitely sound different.”
Redline is said to be theoretically higher than a Twin Cam, but they’re capped right now at 6,000 rpm, which leads me to believe these new motors should be torque monsters. The whole shootin’ match is said to be one or two pounds lighter than the TCs, which makes sense, given the legacy constraints Harley always seems to work within.
[Left side of engine
The left side looks a little more familiar, I suppose. There's not much room in there. I wonder how bad those valve adjustments are going to be. Source photo.]
The new mills are actually using two different size mufflers, due to the emissions equipment, and the header is said to be far easier to remove than the outgoing Twin Cam. The air cleaner "is a high temp/strength type of plastic, and a slight pain in the ass to remove."
Inside the heads, those valves are operated by forked rockers. And valve adjustment? Well, this is a bit of a departure for Harley. Rather than the hydraulic lifters of the Evo and Twin Cam, or the adjustable pushrods of the Shovel, the Milwaukee Eight is sporting locknut style adjusters up top. (I like this type, and I have proselytized about them before. Rather than swapping pricey and hard-to-find shims, everything you need to do a valve adjustment is right there on the bike.) Oh yes, this new mill is also sporting dual-plug heads. I guess that also means this is a single-fire setup. It would have been nostalgic if they could have worked in a dual-fire arrangement, but I guess practicality won out. Vestigal stuff is cool to me.
We talked about interchangeability, too, with current and older models. Here’s what our source was able to give us: “Same transmission cassette, but it’s in a different housing. It’s still divorced from the engine case.”
The clutch changed a bit too. “I don’t like the throw, it’s way out there. As soon as you pull the clutch in just a little bit, you’re disengaging it.” Trike models will be getting an extra plate in the clutch, which sort of stands to reason. Oh, and the clutch on everything will be going juice soon. Apparently my old cable bikes are about to be outmoded.
The compensator sprocket design has also undergone revision. Harley’s been playing with different ramp angles. Given the troubles they saw with the previous version, it sounds about right they’d pay extra attention to this area. Apparently, my major gripe with the Twin Cam — that dadgum sprocket-shaft roller bearing that takes a whole rebuild to access — is still in use. Pity. I hope the engineers found a way to make it survive, but I don’t have high hopes.
This is all the dirt I’ve gathered thus far. Feast your eyes on those photos, and talk amongst yourselves in the comments section.