I've learned alot here on this forum but no one ever brings up the subject of roller rockers here. What their advantages and disadvantages are, when to use them and why or why not use them ect.

 

There is a seperate forum for engine related techie-gee-whiz-bang valve stuff.

Just sayin....

 

I'll take a Rolling Rock thank you.

 

Too bad there isn't one for people who give meaningless replies.

 

You have a point there........... I'll give it a bump up to hear about roller rockers!

 

rumor has it that if you got a cam with a .510 lift or greater rollers are a good idea. They keep the valve train straight on a high lift cam. Less wear on the top of the valve due to the roller vs just scraping the top of the valve stem.

 

I am not sure exactly what the differences are in motorcycles but I have experience building small blocks and the main advantages to a roller rocker is under high lift situations it prevents sideloading the valve stem which extends the life of the valve guides and it also reduces friction at the valve tip which would reduce heat, slow down wear, and free up a couple ponies. I am also not sure how much the rpm levels apply in this particular situation but in higher revving motors you need to either lighten up the reciprocating mass or increase valve spring pressure to keep from experiencing valve float and with higher valve spring pressures the factory stamped rocker arms aren't exactly up to the task. My assumptions with the lack of talk about them in these forums is that the shaft rocker setups in harley is a pretty stout setup from the moco for the average stage one stage two build. The majority of us don't necessarily hot rod these motors and there is alot of excess noice attributed to roller rockers so it may not be what alot of the cruiser folks are really looking for. JMO

 

I think you meant .610 lift.

That's essentially what I've been told. High lift cams or high revving motors. I'm not there yet with my bike. Probably a good thing, harley roller rockers are awfully expensive, compared to sbc.