Harley Evolution Motor Common Problems Install Races Into
Harley Evolution Motor Common Problems Full Of It

I havent gotten inside the came chest yet, but I figure if Im going into it I might as well replace the rockers, pushrods, swap out the lifters, and put in an Andrews EV27 cam, and put a Torrington inner cam bearing in.

Twinkies seem to have some issues, heat is one of them hence the piss-heads coming out now, but I dont know enough guys with twinkies to give any real stats.

Harley Evolution Motor Common Problems Full Of It

I dont dispute that the TC has some issues (particularly the earlier versions), but the author of that page is just full of it.

I like em both. The TC makes more power the whole bike is more modern, of course.

The EVO runs cooler get better fuel mileage but it just feels like its working to cruise 85, where the TC is just loafing along.

The Twin Cam was designed to make factory assembly easier (and of course cheaper) at the cost of most of it being disposable rather than rebuildable.

So if the only thing gained was power, the TC is a total fail.

The EVO had plenty for what it went into.

A cruiser. Harley copied a lot of Japanese design and manufacturing techniques with the TC, and that is one place they had been way ahead of the Japanese with the EVO.

They just need to be checked every 10-20K miles (many bikes want valve adjustments at lower mileages).

TCs do have crank problems when ya start building them over 100hp but few EVOs ever came near 100hp.

My 09 103TC is putting out 99hp109tq with pretty much only pipesACcams and is way better than any of my EVOs that blew up.

I may be a little biased, but I will try to give you MY opinion on it.

Keep in mind all of my problems are coming from a previous owner screw up, so, its not the bikes fault.

Evos, in my opinion, are the better engine if you arent trying to build them up to be high horse power engines.

The good thing about the evolution motor, is that they have the Timken bearing; something Harley has not put in the twin cam since 2002.

Nothing worse than having your non-rebuildable flywheel coming out of true in your post 2002 twin cam because you had no timken bearing.

Evos have gear driven cams, which can be a blessing if something does go south in the cam chest because theyre relatively easy to work on.

Keep in mind that you can put timken bearings on a twin cam flywheel and you CAN go to gear driven cams.

Harley Evolution Motor Common Problems Install Races Into

You simply ship your bottom end out and the mechanicshop will install races into your cases and the bearings on the crank pin, and you can have them true your flywheel and weld it up nice and strong if youd like which is the best way to go.

The only major problem I can tell with the evolution motor is the fact that lifters need replacement every 40,000 miles, but that is an EASY job to do.

Evos will eventually develop a base gasket leak, but proper warming up of the motorcycle will keep this from happening for a LONG time.