The TC is a better motor all around. It has better performance capablities, shorter stroke, smoother, comes in 2 flavors (balanced). The Bikes that have TC are also better in design, larger axles, better bearings, better brakes and the list goes on.

Bathtub shaped combustion chambers, Better valve train geometry (because of the 2 cams), Better flow dynamics of the ports, Cases can hold larger diameter cylinders, Crank triggered ignition, better fuel injection technology, better oil pump and balancers in the "B" motors. And that is just the motor, as stated before the changes to the bikes are also much improved.

The Twin Cam is an air/oil cooled engine as it sprays oil on the underside of the piston for cooling as well, superior design over just air cooling like an EVO for example.

The restrictive heads also have better port flow dynamics allowing a ported set of heads to have straighter ports thanan EVO. They also have a reduced size exhaust valve which actually helps produce torque. As previously mentioned, they have bathtub combustion chambers that help promote increased turbulance in the compressed charge resulting in a better burn.

The cooling area on the fins was also increased by 50%

 

Evo's are actually 81.6 cubic inches, so the difference in size is about 6c.i. TCs have the clunky chain driven cam arrangement, much heavier wristpins and con rods, at least up til the '07s when they were lightened. TCs run noticeably hottter than Evo's. I used to wonder if the overbuilt rods and wristpins were part of the reason for that, but the 96s run just as hot, so I guess it's still a mystery. TCs have jets to spray oil on the bottoms of the pistons that Evo's don't have. By the way, Evo's had no particular problems with wristpin or rod failure. Evo's get better fuel mileage. Evo heads flow more air than TC heads. Most presume this was done to sell 95" kits for TCs.
Evo's have D shaped combustion chambers; TCs have bathtub shaped chambers. Although the latter is supposed to be better, again, it doesn't seem to work any better in this case.
I have to say that the Evo appears to be the better engine.

 

quote]The TC is a better motor all around. It has better performance capablities, shorter stroke, smoother, comes in 2 flavors (balanced). The Bikes that have TC are also better in design, larger axles, better bearings, better brakes and the list goes on.

Bathtub shaped combustion chambers, Better valve train geometry (because of the 2 cams), Better flow dynamics of the ports, Cases can hold larger diameter cylinders, Crank triggered ignition, better fuel injection technology, better oil pump and balancers in the "B" motors. And that is just the motor, as stated before the changes to the bikes are also much improved.

The Twin Cam is an air/oil cooled engine as it sprays oil on the underside of the piston for cooling as well, superior design over just air cooling like an EVO for example.

The restrictive heads also have better port flow dynamics allowing a ported set of heads to have straighter ports thanan EVO. They also have a reduced size exhaust valve which actually helps produce torque. As previously mentioned, they have bathtub combustion chambers that help promote increased turbulance in the compressed charge resulting in a better burn.

The cooling area on the fins was also increased by 50% [/quote]

That's what the harley literature said when the TC came out. Piston squirters, better oil pump, 50% more cooling area should all equal better cooling. Unfortunatly that's not how it turned out. The TC's oil actually runs 50 or more degrees hotter than the Evo's. I highly doubt it's because of the greater power output. The 73 ci sportster engine makes 79 ft lbs at the crank (slighly more than 1 hp per ci) and runs 50 or more degrees cooler than the twin cam. The 88 ci TC engine made 86 ft lbs at the crank (slightly less than 1 hp per ci.).

The TC was suppose to be the undestructable overbuilt motor, but we have people doing cam chains at 25-50K mi. That's more frequently than the 50-100K mi. it took base gaskets to start to leak on the Evo's. On top of that when base gaskets leaked they did nothing to endanger the engine. When the tensioner shoes shred you put the engine in danger of a failure.

The TC is a more powerful engine, but is it due to it being a better engine or was it due to it being a bigger engine? 80 ci (Evo) vs. 88 ci (TC). Following the 1 hp per ci rule the TC should have produced 8 ft lbs more just on displacement. Anybody have stock tq ratings for the 80 Evo?

The TC looks like a better engine on paper, but in practice the Evo is a better and more reliable engine. Just my opinion of course.

 

This is a good thread. Not enough good threads now that post ****** have taken over. I enjoy learning about the differences in theTC vs Evo. Thanks

 

Thanks guys.. As I know a lot of guys favor one over another, I wanted to make sure I was pretty objective about it.. I love 'em both.. Enjoyed the heck out of my 04 TC, and was still amazed at the abuse the old 90 Evo bike withstood by previous owners and still was strong as an oxe and not a smoker by any means.. though it did mark it's territory when parked.

 

As an owner of a 1992 FLHT-Police bike, I have researched all the Screamin' Eagle and aftermarket options avaiable to improve the bike, and offer the following observations: the remanufactured by Harley replacement motors (still available, about $2600.oo thru dealer have the improved cases), ALWAYS change out the cases (the stator flange usually breaks, other defects, also), the oiling system is outdated, also (below 1900 rpm the crank gets no oiling, and 1050 rpm is required min. rpm for no eng. damage at idle), this can be fixed via a Total Performance oil pump (about $400), the evo oil pumps have a "wet sumping" problem, also fixed via TP oil pump, if you don't install a molded stator, it will mess up, there is a 3 phase, 38 amp updated charging system avail., the aforementioned tranny alignment prob.s (oil leaks), cyl. base leaks (mod avail.), Twin Cam lower end with modern lower end and superior oiling is better for high output engines, the chain drive for cams is easily fixed, the torque and hp at 110 cubic inches is far superior to 80 cubic inches, however, a screamin' eagle SE-57 cam in conjunction with hi-compression pistons will easily keep up with the more modern twin cams, at the expense of decreased engine life and increased expense of higher octane fuel. In summary, newer and more expensive is always better in terms of performance, however, there is something to be said for old Harleys that seem to last forever (Die, Jap Bike, Die). "Take that, yuppie youngsters that are killing this country. Old Harleys never die, they just cost more!

 

Well I was enjoyin the post until that last line!! Im 27, love old harleys and wish i had the money for the brand new ones, and I personally dont feel that im "Killing the Counrty". I work my *** off to pay my way. This thread it ment to inform and decuss the Evo and TC with out bashing, and stupid comments from jerks.


Sorry for the rant fellas, just dont see what that last line did to help the topic....

 

I think the Twin Cam would be a much better engine then the EVO if H-D didn't mess it up by going cheap with some key components. Sure using a press fit flywheel and weaker (non Timkin) bearing saved them money over the EVO but at what cost to us? No doubt the Twin Cam has a much better top end. I was never a fan of older big twins (heavy valve train/terrible geometry) but the more I learn the less I'm impressed with what Harley has done with the TC. I understand H-D has to keep manufacturing costs under control but I would have gladly paid an extra $500+ for my 09 Night Train if the extra $ got me a engine with a bottom end at least as strong as the engines that came before it.

 

Well being this post started over 3 years ago, it's still has valid points. I have owned 2 evos and 1 twin cam, so here's my take. The evo's to me seem like a smoother running motor. My latest evo which is box stock, would smoke my stock '03 ultra. Don't understand why but the twin cam needs to me played with to get it going, where the evo just goes. I had a reman done in 1994 due to a bad lifter and never had any issues with the reman motor. The evo is carbed and the twin cam had fi. That made starting in the dead of winter super easy over the carbed bike. No coughing an sneezing. They dont make any new custom parts for the evos, but there are lots of used one around, cheap. So I would say to anyone looking for a Harley, buy the bike you like and can afford.,,

 

I have an '03 B TC. Is that AFTER they dropped Timken bearings? It is a carb'd bike and I sure do like it...