Do accelerated lift cams increase valvetrain wear or stability?

 

Fast ramped lobes will increase valvetrain ware. I've been recommended Patriot or Crane Duals w/ fast ramped cams. Even if they don't reach .6 valve lift.

 

Not to the best of my knowledge......it's going to sound like a sewing machine a little more than normal (mine will sound like this after the install) but I'm pretty certain that wear and stability will remain about the same as any other cam

 

Yes they will,but most cam manufacturers will tell you what valvetrain modifications are required to run their grind.Technically,all the performance cams on the market have accelarated lift when compaired to stock.If you follow the manufacturer's recommendations you shouldn't have problems.

 

Oh, are you talking about that Vinci stuff?

 

No, just in general.

Anyone know where the technology comes from?

 

The technology? You mean the idea of using fast ramped lobes? It's to pop the valve open quickly and enough to get the air in the chamber. (Or Out, for exhaust.

 

of course, but where did that idea come from, it had to be a requirement or a need? right? what automotive industry? why even have them?

 

A need for more power. Slow lobes, spend all the time @ low lift levels where the head flows poorly.

Quick, steep ramps spend their time up top where the head flows more CFM. Also, they may provide less lobe around the base, where overlap is present. This is where you get the idea of fast lobes idle better.

Example.

Comp 3713 (x-e)
.006 - 273*
.050 - 220
.200 - 138

Comp 3720 (x-er)
.006 - 269
.050 - 220
.200 - 143

See where the small advertised duration on the faster ramped x-er is lesser. But check out .200 duration. More duration @ higher lift = more power.

Make sense? You see more cfm @ higher valve lift.

 

If they are calling it an accelarated lift cam,they are only telling you that it has faster ramps that the cam it replaced.The only thing you can go by is what the manufacturer tells you,unless you have equipment to read and compare profiles,a cam with identical published specs from one manufacturer can behave totally different than same cam from another manufacturer.