EVo vs. Twin cam
#1
01-19-2007, 04:05 PM
EVo vs. Twin cam
[sm=biker2.gif]What are the main differences besides displacement between the older but hugely popular Evolution motor and the Twin cam 88"? Can you still get an EVO from Harley? ( If this is a dumb question, forgive me, I am a converted Crotch Rocket jockey.)
#2
01-19-2007, 04:10 PM
RE: EVo vs. Twin cam
There are many. The shape of the combustion chamber in the heads. The Evo had one cam while the twin cam has two. The Evo used gear driven cams, etc.
And they only way you can get a Evo now is through Harley's remanufacturing program. You can also buy a S&S engine based off the Evo.
And they only way you can get a Evo now is through Harley's remanufacturing program. You can also buy a S&S engine based off the Evo.
#3
01-19-2007, 04:44 PM
RE: EVo vs. Twin cam
The evo was the last high tech carb v-twin from the mo-co before the EPA got a hold of a good thing and made H-D go to the twin cam. The single gear driven cam verses dual chain driven cams is probably the biggest difference. The Evo heads were the correct size for it's displacement.. The stock TC heads are the same size as the evo heads but for a larger displacement. (unconfirmed but from some tech article I read somewhere).. Therefore with a TC, a few good mods to do are, swap out the chain cam drive for an S&S or similar gear drive, and have a good pro do some head work or swap to better suited heads.
When my current engine starts showing it's age, I'm going to tear down, do a top-end big bore with heads, cylinders and cams and a gear cam drive.. Just get it all done at once.
Evo's were bulletproof. TC's haven't earned that reputation yet.
One thing in favor of TC's.. The transmission (FINALLY) attaches directly to the back of the engine case on the softail versions. On Evo's, engine and tranny were attached to the frame, with the primary chain case coupling the two. A lot of torsion going on there.. Now with the TC's, the tranny is "part of" the crank case as one member.. more solid. Primary leaks were common with Evo's because of this.. If out of alignment, the best seals in the world couldn't solve it.. I know from experience.
I'd be willing to bet oil delivery is probably improved on the TC's also.. but that's a suspicion, not verified.\
TC88B's (softails) are also counterbalanced, whereas no evo was counterbalanced, that I'm aware of.. Less vibration for a balanced solid-mount vs non-balanced.. This I can vouch for also. Dyna's and tourbikes don't have the counterbalancing but instead use rubbermounted engines so the vibrations are isolated in theory from the rest of the bike.
When my current engine starts showing it's age, I'm going to tear down, do a top-end big bore with heads, cylinders and cams and a gear cam drive.. Just get it all done at once.
Evo's were bulletproof. TC's haven't earned that reputation yet.
One thing in favor of TC's.. The transmission (FINALLY) attaches directly to the back of the engine case on the softail versions. On Evo's, engine and tranny were attached to the frame, with the primary chain case coupling the two. A lot of torsion going on there.. Now with the TC's, the tranny is "part of" the crank case as one member.. more solid. Primary leaks were common with Evo's because of this.. If out of alignment, the best seals in the world couldn't solve it.. I know from experience.
I'd be willing to bet oil delivery is probably improved on the TC's also.. but that's a suspicion, not verified.\
TC88B's (softails) are also counterbalanced, whereas no evo was counterbalanced, that I'm aware of.. Less vibration for a balanced solid-mount vs non-balanced.. This I can vouch for also. Dyna's and tourbikes don't have the counterbalancing but instead use rubbermounted engines so the vibrations are isolated in theory from the rest of the bike.
#4
01-19-2007, 04:46 PM
RE: EVo vs. Twin cam
Until '93 when HD changed the cam bearings to "improve" the EVO, those suckers were almost bullet proof. Might get a base gasket seep at about 50K, but that was no big deal, and cheap to fix if you really wanted to. All you had to do was change oil, keep water in the battery, and make sure that #$%@ regulator plug at the front left of the engine was tight.
TC88's have those wonderful cam chain tensioners...........Other than some problems with the '99 models, the early ones ran fine. Things appear to have been going down hill since about '04. Still a good bike IMHO. Only rode an '07 once, but it appeared to me to be a good bike, just made some really interesting sounds.
TC88's have those wonderful cam chain tensioners...........Other than some problems with the '99 models, the early ones ran fine. Things appear to have been going down hill since about '04. Still a good bike IMHO. Only rode an '07 once, but it appeared to me to be a good bike, just made some really interesting sounds.
#5
01-19-2007, 06:40 PM
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RE: EVo vs. Twin cam
ORIGINAL: jbnl163
[sm=biker2.gif]What are the main differences besides displacement between the older but hugely popular Evolution motor and the Twin cam 88"? Can you still get an EVO from Harley? ( If this is a dumb question, forgive me, I am a converted Crotch Rocket jockey.)
[sm=biker2.gif]What are the main differences besides displacement between the older but hugely popular Evolution motor and the Twin cam 88"? Can you still get an EVO from Harley? ( If this is a dumb question, forgive me, I am a converted Crotch Rocket jockey.)
http://www.heavydutycycles.com/evotecq.htm
cj
#6
01-19-2007, 07:40 PM
RE: EVo vs. Twin cam
ORIGINAL: Babs
The evo was the last high tech carb v-twin from the mo-co before the EPA got a hold of a good thing and made H-D go to the twin cam. The single gear driven cam verses dual chain driven cams is probably the biggest difference. The Evo heads were the correct size for it's displacement.. The stock TC heads are the same size as the evo heads but for a larger displacement. (unconfirmed but from some tech article I read somewhere).. Therefore with a TC, a few good mods to do are, swap out the chain cam drive for an S&S or similar gear drive, and have a good pro do some head work or swap to better suited heads.
When my current engine starts showing it's age, I'm going to tear down, do a top-end big bore with heads, cylinders and cams and a gear cam drive.. Just get it all done at once.
Evo's were bulletproof. TC's haven't earned that reputation yet.
One thing in favor of TC's.. The transmission (FINALLY) attaches directly to the back of the engine case on the softail versions. On Evo's, engine and tranny were attached to the frame, with the primary chain case coupling the two. A lot of torsion going on there.. Now with the TC's, the tranny is "part of" the crank case as one member.. more solid. Primary leaks were common with Evo's because of this.. If out of alignment, the best seals in the world couldn't solve it.. I know from experience.
I'd be willing to bet oil delivery is probably improved on the TC's also.. but that's a suspicion, not verified.\
TC88B's (softails) are also counterbalanced, whereas no evo was counterbalanced, that I'm aware of.. Less vibration for a balanced solid-mount vs non-balanced.. This I can vouch for also. Dyna's and tourbikes don't have the counterbalancing but instead use rubbermounted engines so the vibrations are isolated in theory from the rest of the bike.
The evo was the last high tech carb v-twin from the mo-co before the EPA got a hold of a good thing and made H-D go to the twin cam. The single gear driven cam verses dual chain driven cams is probably the biggest difference. The Evo heads were the correct size for it's displacement.. The stock TC heads are the same size as the evo heads but for a larger displacement. (unconfirmed but from some tech article I read somewhere).. Therefore with a TC, a few good mods to do are, swap out the chain cam drive for an S&S or similar gear drive, and have a good pro do some head work or swap to better suited heads.
When my current engine starts showing it's age, I'm going to tear down, do a top-end big bore with heads, cylinders and cams and a gear cam drive.. Just get it all done at once.
Evo's were bulletproof. TC's haven't earned that reputation yet.
One thing in favor of TC's.. The transmission (FINALLY) attaches directly to the back of the engine case on the softail versions. On Evo's, engine and tranny were attached to the frame, with the primary chain case coupling the two. A lot of torsion going on there.. Now with the TC's, the tranny is "part of" the crank case as one member.. more solid. Primary leaks were common with Evo's because of this.. If out of alignment, the best seals in the world couldn't solve it.. I know from experience.
I'd be willing to bet oil delivery is probably improved on the TC's also.. but that's a suspicion, not verified.\
TC88B's (softails) are also counterbalanced, whereas no evo was counterbalanced, that I'm aware of.. Less vibration for a balanced solid-mount vs non-balanced.. This I can vouch for also. Dyna's and tourbikes don't have the counterbalancing but instead use rubbermounted engines so the vibrations are isolated in theory from the rest of the bike.
#7
01-19-2007, 08:37 PM
RE: EVo vs. Twin cam
It sure would be hard to improve upon an Evo,but the few things Harley in the TC were a big improvement.
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#8
01-19-2007, 10:57 PM
RE: EVo vs. Twin cam
ONe thing that hasn't been mention is that the Evo heads, the surface area, or "squish band" (where air is force into the combustion chamber) area was on only one side of the head, in the TC, it is all around the cumbustion chamber which creates a much higher percentage of burnor efficient burn, and in turn more power...
#9
01-19-2007, 11:09 PM
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#10
01-19-2007, 11:18 PM
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RE: EVo vs. Twin cam
One good thing about Harley-Davidson is intra - Brand recognition. Softails, Dynas, Touring, Sportster. All but one share a great deal of engineering. The Sportster is the Odd Bike out. The Evo engine, like the Twin Cam has been modified for each line to suit the Legend of the Line.
And like many folks, I can't address most other lines beyond what I own. Touring, EVO and TC, and pre rubber mounted Sportster. That'a what we own.
The one thing I can vouch for is that as early as 1995 and definitely 1996, The Evo engine in the Touring line did have a mated transmission. No Torque framed mounted issues her. Look up Transmission in any after market vendor site and what you will find is a lot of trannies for Softails, that are not applicable to Touring/FXR's or similar tranny mated machines.
Just my observation. Evo's and TCA, non balanced,ARE different but not all platforms mount, shift or oil bag the same. Lot's of good info in the EVO section and even there not all answers apply to all platforms.
And like many folks, I can't address most other lines beyond what I own. Touring, EVO and TC, and pre rubber mounted Sportster. That'a what we own.
The one thing I can vouch for is that as early as 1995 and definitely 1996, The Evo engine in the Touring line did have a mated transmission. No Torque framed mounted issues her. Look up Transmission in any after market vendor site and what you will find is a lot of trannies for Softails, that are not applicable to Touring/FXR's or similar tranny mated machines.
Just my observation. Evo's and TCA, non balanced,ARE different but not all platforms mount, shift or oil bag the same. Lot's of good info in the EVO section and even there not all answers apply to all platforms.
