Issue link: https://read.dmtmag.com/i/738714
28 nNovember 2016n www.thunderpress.net THUNDER PRESS by Kip Woodring Let's take up here, where we left off last issue. Last time, we covered the most obvious and important "fea- tures" of The Motor Company's latest power plant. This time around, the focus is on the many not inconsider- able improvements and innovations applied to the "supporting players" which collectively make the new Milwaukee-Eight the best Harley Big Twin ever made. To get up to speed on this technical examination, pull out last month's THUNDER PRESS and refresh your memory, or go to thunderpress.net where the fi rst installment complete with the fi rst nine in-depth illustrations and expla- nations is now posted. Having done that, let's delve further into the inner workings of the Milwaukee-Eight. 4 HARLEY-DAVIDSON MILWAUKEE-EIGHT 107 ENGINE PART 2 A whole new game The Motor Company hits it out of the ballpark Crankcases for the M-8 are all new, over 20 percent stronger, with a new front engine mount interface and a relocated oil fi lter mount being the most obvious changes. The crankshaft position sensor is now located on the right side case at the bottom of the engine, a move also dictated by the addition of the new balancer. Inside the cases are new shouldered cylinder studs, spaced farther apart and reconfi gured to handle the larger cylinders. The changes were made to accommodate the new gear-driven balance that lives in front of the crankshaft. The factory is quite rightfully proud of their investment in the high-tech machinery required to make these cases (not to mention the heads) right down to robotic powder-coating that (pardon the pun) "fi nishes" the process. The new-for-2017 interface between engine and transmission cases uses a new metal- backed gasket with beaded surfaces to seal internal passages between oil tank and engine. Makes sense, when you consider the engine now breathes into this area. The new crank runs a much larger, stiffer crank pin, as well as bigger connecting rod bear- ings for nicely increased load capacity. (Perhaps a hint of the potential inherent in this new power plant?) Crank position sensor "teeth" are machined into the right fl ywheel because the left fl ywheel has a new press-fi t, constant-mesh, anti-backlash "friend" in the form of the balancer drive gear. Ah! The balancer! This clever device amounts to a single counterweight that passes between the fl ywheels, keeping things pretty compact, while doing a better, more effi - cient job than the older TC "B" motor's chain-driven design. The gear on the balancer is a so-called "scissor" type which keeps any gear lash and associated noises to an absolute minimum. Now… about this new single cam and its attendant drive system. A close look at the pic- ture shows most of what you need to know. The cam itself is lighter, quieter and built into a single component from assembled pieces… namely the cam and its gear. But that cam also has larger base circles, and lobes to match the characteristics of the 4-valve heads. The cam is chain driven as you see, but what isn't shown is the hydraulic tensioner, itself a new design which is maintenance free. The oil pressure relief valve is no longer situated in the cam plate either…