What's the advantage of twin cam

[jammer45u]

It seems like there are quite a few problems with the twin cam design. Engines failing to total destruction with less than 30,000 miles is a disgrace for any manufacturer. Then to let the problem go on and on, year after year... Why? What is the big advantage two cam's?

[Pikeslayer]

Twin Cam is what they called it. I don't believe it was the primary driver for the redesign. One of the experts will chime in on the pro's and con's of the Twin Cam over the Evo.

[DBotkin]

So, do you have any numbers to back up your claim that twin-cam H-D engines self destruct at less than 30K miles? I'd be interested... since mine's over 30K now, as are those of many others I know, and no one that I can recall has had their TC turn into a grenade.

If you're talking about the known weak points of the motor, I would challenge you to come up with any motor from any manufacturer that doesn't have some item requiring repair or replacement at intervals somewhat more frequent than the design engineers intended. Still, we seem to toddle on.

[The Student]

Originally Posted by DBotkin

So, do you have any numbers to back up your claim that twin-cam H-D engines self destruct at less than 30K miles? I'd be interested... since mine's over 30K now, as are those of many others I know, and no one that I can recall has had their TC turn into a grenade.

If you're talking about the known weak points of the motor, I would challenge you to come up with any motor from any manufacturer that doesn't have some item requiring repair or replacement at intervals somewhat more frequent than the design engineers intended. Still, we seem to toddle on.

Right on

[springer-]

http://www.v-twinforum.com/forums/ev...aving-evo.html

That is an old "discussion" about the subject. Some of the pictures are missing now but it still has the meat of the discussion. Enjoy

[nightrob]

Didnt the "twin cam" originally come out in 1928? The JDH?

[prophet]

Originally Posted by DBotkin

So, do you have any numbers to back up your claim that twin-cam H-D engines self destruct at less than 30K miles? I'd be interested... since mine's over 30K now, as are those of many others I know, and no one that I can recall has had their TC turn into a grenade.

If you're talking about the known weak points of the motor, I would challenge you to come up with any motor from any manufacturer that doesn't have some item requiring repair or replacement at intervals somewhat more frequent than the design engineers intended. Still, we seem to toddle on.

A good friend of mine had his nuke twice...once at 30K and once at 60K. The dealer told him that it is to be expected that you change the bearings in cam chest (inner and outer) every 30K. Mine nuked at 38K.

[vindex1963]

Originally Posted by nightrob

Didnt the "twin cam" originally come out in 1928? The JDH?

Yes they did.

"JH, JDH Two - Cam, 1928 - 1929 Twin-cam and even eight-valve machines had formed the cutting edge of Harley-Davidson's official racing efforts since the First World War, yet the ordinary road-going motorcyclist could only dream of such performance. All that changed in 1928 when Harley offered a two-cam motorcycle to the general public at an affordable price. These special J-series machines were available for two years only, as the 61-inch JH and the awesome 74-inch JDH, which were priced at $360 and $370 respectively."

[Tech23]

I beleive the twin cam design was to reduce the push rod angle as the engine displacement got larger.

Bash if em you like...IMO (the HD air cooled V twin, all of em) one of the coolest sounding engines ever. Not bashing the imitators here either...LOL.

Tech23

[msocko3]

Originally Posted by prophet

A good friend of mine had his nuke twice...once at 30K and once at 60K. The dealer told him that it is to be expected that you change the bearings in cam chest (inner and outer) every 30K. Mine nuked at 38K.

I have one past 30k, have a neighbor with one that has 57k and know of others with 50k+ miles and no problems. Me thinks the dealer is full of sh!t. Now if your running it until the old style tensioners take a dump and take out stuff in the cam chest thats a whole nother subject. You have to inspect the tensioners from time to time and keep tabs on the wear and replace them before they get you or switch to gear drive or the new style tensioner conversion.

[prophet]

Originally Posted by msocko3

I have one past 30k, have a neighbor with one that has 57k and know of others with 50k+ miles and no problems. Me thinks the dealer is full of sh!t. Now if your running it until the old style tensioners take a dump and take out stuff in the cam chest thats a whole nother subject. You have to inspect the tensioners from time to time and keep tabs on the wear and replace them before they get you or switch to gear drive or the new style tensioner conversion.

I inspect my tensioners every 15-20K. I recommend they be checked at 20K (or first opportunity)to anyone who asks. My first set was worn 95% at 18K on my 01 RKC, the tensioners in my 06 Ultra were worn 35% at 32K. The dealer may be full of it, because I know of people that haven't even check tensioners at 60K (stock bikes), however that is against my past experience as 3 other friends have had tensioners nuke because they have gone anywhere from 27K to 45K without ever checking them. The average mileage of all seems to be about 30K. I do believe the newer ones last longer, but it's a crap shoot. When you spend 20K or more on a bike you should expect it to last longer. My current build is listed below and this post doesn't mean I don't like HD, club rules say I have to ride HD...I'd have to quit if I rolled in on anything but. I'd still ride one anyway. However, the MOCO should be ashamed of themselves. If I had a choice of motors to put in my 06 Ultra (without a major conversion), I'd put in a 110" EVO style!

[bill corkey]

i had a '99 ultra, the first year for twin cam. put 70 plus k miles on it;never had any engine problems. Traded for a '07 RK

[mgb939]

Had a '04 Ultra with 60+K, replaced chains and tensioners at 38K, traded for a '09 Ultra. Me thinks it's a good motor, just sayin'.

[nightrob]

Originally Posted by vindex1963

Yes they did.

"JH, JDH Two - Cam, 1928 - 1929 Twin-cam and even eight-valve machines had formed the cutting edge of Harley-Davidson's official racing efforts since the First World War, yet the ordinary road-going motorcyclist could only dream of such performance. All that changed in 1928 when Harley offered a two-cam motorcycle to the general public at an affordable price. These special J-series machines were available for two years only, as the 61-inch JH and the awesome 74-inch JDH, which were priced at $360 and $370 respectively."

Tahnks for elaborating.. I was fishing to see if someone else knew.. Its funny to think some folks think that this is new technology to Harley!!

[Krayven Sumhead]

My pal just turned over 110,000 miles on his '04 'staged one' stock TC88. Had the cam chain tensioner's replaced at 80,000 miles. He's put on 6,000 miles in the last two months. There are a lot more TC88's running than grenading.