Harley Boys: Evol versus Twin Cam Engine

MotoSook · 12-30-2005, 08:24 AM

Here's what I found for a basic intro:

Evolution: 1983-1999

In 1984 on the heels of a bold employee buyout of AMF, the motor company went public and introduced its now famous redesign of the V-twin. This radical new design utilized styled square blocks to house the valve train. This motor, revered as the Evolution engine is known amongst Harley enthusiasts as "the Blockhead".

Twin Cam 88: 1999-Present

With numerous American motorcycle manufacturers trying to surface and resurface, Harley-Davidson introduces its most revolutionary engine yet. The Twin Cam 88 gets its name from its two cams versus the single cam in all its ancestors. This motor also goes by the nickname "Fathead" for just exactly that, bigger heads. With this new engine design Harley-Davison puts one more notch in its insurance for success.

So! The CFO of my company wants a Harley, and he knew I was a rider, but I don't know much about Harleys.

What is the performance difference between the two (Evol and 2-cam)? What about reliability?

Thanks,

5axis · 12-30-2005, 08:42 AM

Not helpfull but funny

http://cycletownusa.com/HarleyInetcycletown.htm

BTW why is the 900ss FS?

MotoSook · 12-30-2005, 08:47 AM

Hi Dave. The 900SS is too slow. I thought I could live with the torque w/o speed...but it's not as enjoyable as the Ninja. If we lived in the hills with lots of curves, I might have a different opinion. I'm in no rush to sell it so I may be riding it in the spring.

gaijindabe · 12-30-2005, 08:51 AM

You mean the "twin cam" is NOT double over head cams - per bank??

Man alive - it seems they have not yet caught up with Briggs & Stratton in terms of technology..

5axis · 12-30-2005, 09:02 AM

Souk bring that thing out to the track next summer, it will be more than fast enough.

More hardlyableson fun.
http://www.goingfaster.com/angst/main.htm

Have your CFO swing into TAG in geneva. Maybe he can be saved from the chromosexual lemmings? (ride by the filling station in downtown St Charles on a summer sat/sun and you will see exactly what I mean)

MotoSook · 12-30-2005, 09:11 AM

Dave, if I don't sell the Duc, it'll likely be reborn into something of a track bike. Just don't tell Heather I'm at the track on 2-wheels. I'll be living in the the garage!

Unfortunately, I think the CFO has his heart set on a Harley, specifically a Fat Boy. He's not a sport rider (or A rider) like we are, and he is just looking to go cruising with some of his Harley friends or cruise to work on sunny Fridays...maybe rack up 3000 miles a year.

oldE · 12-30-2005, 02:14 PM

"Thank you, Ladies and Gentlemen. He'll be here all week. Isn't he great? How about a big hand for 'tcar'?"
Good one.
Les

BlueSkyJaunte · 12-30-2005, 02:52 PM

Last time I heard that one I tripped over a Knucklehead.

lm6y · 12-30-2005, 03:55 PM

Is the twin Cam 88 the liquid cooled V-Rod motor?

I saw a special when the V-Rod came out, that explained that Harley couldn't get the engine lined out. It was shipped to Stuttgart to the Porsche R&D department, and they almost completely re-designed it.

Imagine that, it works now.

tcar · 11:32 AM

Quote:

Originally posted by lm6y
Is the twin Cam 88 the liquid cooled V-Rod motor?

Nope, not even close.

TC 88 is 45 degree air cooled 1450 +/- cc's. Chain driven twin cams with Foot long pushrods.

V-Rod is 60 degree water cooled, 1140 +/- cc's. DOHC.
Think it's got about a 8500 rpm redline. (Very similar to a Yamaha V-max.)

Just kidding above, I've heard Harleys are pretty reliable now. Still slow and loud tho.

Jeff Higgins · 10:40 PM

I've owned Harleys for over 25 years now, and have rolled up well over a quarter million miles on them. My current bikes are a 2000 Road King with the Twin Cam 88 engine, and an old hot-rod Sportster ('76).

The Twin Cam bike is the best Harley I have ever owned, hands down. It now has over 70,000 absolutely trouble-free miles on it. It has some very worthwhile improvements over the 80 inch Evo, even beyond its namesake twin cams. Included are improved oiling, improved cooling, much larger crank pins, shorter stroke, and bigger bore. The old Evos ran a 3.5" bore with a 4.25" stroke; massively "undersquare". The Twin Cam drops the stroke to 4.0" and ups the bore to 3.75". The reduced piston travel should result in longer life.

Outside of the motor itself are other worthwhile improvements made in the Twin Cam era. Braking is very noticably improved. Vibration is all but gone with the counterbalanced Twin Cam 88 "B" motor installed in the Softail frames, and almost unnoticeable in my touring frame and the Dyna family. These use a very effective rubber mounting system to isolate the motor/primary drive/transmission from the frame. The transmission is now bolted to the back of the motor and the frame, where in the past it was completely seperate from the motor and mounted only to the frame.

Frames themselves, and suspensions have been improved as well. Where the Softails used to ride damn near as rough as the rigids they are meant to resemble, they now serve quite well as touring bikes. Their touring line (Road King, Electra Glide, Tour Glide) have noticeably stiffer frames, better brakes, and better handling than ever. They have come a long ways even since the Evo era.

The Twin Cam 88 does, however, have one achile's heel. The cams are chain driven and those drive cahins tend to give some trouble. Sound familiar? The first year bikes were known to eat up rear outboard cam bearings due to the side loads put on them by the chain and its tensioner. Harley re-designed the bearing the next year, and they apparently fixed it as far as catostrophic failure, but long-term wear remains a concern. S&S and Andrews both provide gear driven cams that totaly solve the problem. At 70,000 miles I'm starting to think about a set for mine.

It does seem as though each generation of Harley gets measurably better. My experiences span the Shovelhead, Evo, and now Twin Cam eras. My Shovels needed a top end job at least every 30,000 miles. They vibrated so hard that they literally shook themselves apart. You had to be ready to wrench at any time. The Evo was better, with the motor being trouble-free for as long as I had it. It still vibrated a lot, being rigid mounted, but the quality of the parts getting shaken were better, so they lasted far longer. It was really pretty trouble-free, especially compared to the Shovel. The Twin Cam, however, brings it to a whole new level. Maybe too good.

Reliable Harleys, believe it or not, are seen as a mixed blessing by us old dogs. It used to be if you saw some one on the road, you could instantly relate. You knew what they were going through just to keep it on the road, you knew they were enthusiastic and dedicated enough, and sometimes inventive enough, to keep the thing running. Today, however, any putz with enough cash can ride one. The gene pool has been severely watered down by the new age Motorclothes wearing weekend warriors. Oh well, maybe that's a small price to pay to ride what has finally become a reliable machine. Steer your CFO towards a Twin Cam. If he doesn't know enough about Harleys to know which one he wants, then this is the one that he needs. He won't even have to know how it works.

ErVikingo · 12-30-2005, 08:15 PM

I ride a VRod and love it.........

Hoots · 12-31-2005, 06:14 AM

What do Harleys and dogs have in common?

They both like to ride in the back of pick-up trucks.

What is the difference between Harleys and Hoovers?

The size of the dirt bag.

If you're going to purchase a HD, get a 2000 or later model. The pre-2000 88 inch engines have cam bearing issues. The 2000-2006 models are quite reliable, and it pains me to say that.

If this is your boss's first mc, have her buy a $600 used bike to learn on. It sucks to drop a $20k bike! Plus, after she has learned to ride the $600 bike she can recoup that money by selling in the want ads.

gaijindabe · 12-31-2005, 11:44 AM

Quote:

Originally posted by gaijindabe
You mean the "twin cam" is NOT double over head cams - per bank??

Apparently it is... I take it back..

Flatbutt1 · 12-31-2005, 08:16 PM

buddy of mine just bought the Street V Rod. Lemme tell ya that is one sweet ride. Just may be the next stable mate for my Beemer.

asphaltgambler · 01-01-2006, 10:46 AM

The twin cam engine has many improvements over the Evo. Larger crank surface/pins and larger bearings, better oiling system. The oil pump is integral and the lifter blocks are one piece with the case instead of bolt-on. Less potential oil leaks.

The twin cams (in case) provide much improved valve train geometry and are chain driven. The chain set-up reduces bad harmonics transmitted from the crank and makes for less noise. Evo is gear-on-gear

Improved geometry (angle from the cam to the rocker arms) also results in quieter valve train operation and reduced stress and temperatures compared to the Evo. There is about a 30% increase in cooling fin area compared to the Evo

The twin cams are much better platforms for serious performance engines.