Roller Rockers?
#2
The following users liked this post:
barrygreen (01-19-2019)
#3
Roller tips are a good thing IF you use quality stuff
They do a couple things for high lift cams
Less parasitic drag and less wear on the guide from the valve wanting to go sideways.
As far as when the Lift becomes too much for scrub tappets is always an argument.
However, I feel the answer is- when in doubt do it, as it will never hurt anything even for lower lift cams.
If I had to pick a mandatory lift number for rollers it would be around the high 500 mark, perhaps conservative, but safe.
They do a couple things for high lift cams
Less parasitic drag and less wear on the guide from the valve wanting to go sideways.
As far as when the Lift becomes too much for scrub tappets is always an argument.
However, I feel the answer is- when in doubt do it, as it will never hurt anything even for lower lift cams.
If I had to pick a mandatory lift number for rollers it would be around the high 500 mark, perhaps conservative, but safe.
#5
Not required and will make more noise than OEM rockers. Running OEM rockers with TMan 600SM cams in an all bore 107 and S&S rollers rockers on my higher compression 98" motor with CR595 cams; the 107 can barely hear the valve train in the 107 but not so much with the 98". Not annoying, just saying you will hear roller rockers over OEM. IMHO, not worth the $$, nothing to be gained on the dyno and the miles that most of us put on these bikes, guide wear is not an issue.
#6
Guide wear is a pretty big deal esp if we are talking performance.
If we have a big cam , we have big springs, and we might just have a lot of other stuff too!
My 50 deg cut valves and seats, way narrow, and way to the top of the margin would not like any lateral thrust at all.
The narrow high angle seats are prolly only good for 20K anyway.
They don't need the extra thrust tax .
So there is no blanket statement or a general fix for everyone here.
But when in doubt and already there....rollers look pretty appetizing, in my opinion,
but WtH do I know.
If we have a big cam , we have big springs, and we might just have a lot of other stuff too!
My 50 deg cut valves and seats, way narrow, and way to the top of the margin would not like any lateral thrust at all.
The narrow high angle seats are prolly only good for 20K anyway.
They don't need the extra thrust tax .
So there is no blanket statement or a general fix for everyone here.
But when in doubt and already there....rollers look pretty appetizing, in my opinion,
but WtH do I know.
#7
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#8
#10
Roller rockers can contribute to increased valvetrain noise. Proven fact.
We have had clients on strict budgets that opted out many times, and have incredibly quiet valvetrains on even very aggressive cams.
Are they a 100% "need"?......no.
Scott
We have had clients on strict budgets that opted out many times, and have incredibly quiet valvetrains on even very aggressive cams.
Are they a 100% "need"?......no.
Scott
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HILLSIDE MOTORCYCLE & MACHINE, INC.
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HILLSIDE MOTORCYCLE & MACHINE, INC.
HARLEY-DAVIDSON SPEED & SERVICE CENTER
5225 SOUTH MAIN ST., MUNNSVILLE, N.Y. 13409
Sales/Support 315-495-6650
www.hillsidecycle.com
Walk-in Retail Showroom
Complete H-D Machine Shop
Case & cylinder boring
Complete Cylinder Head Shop
High-Performance Engine Kits
Crank Rebuilding
Direct Link & PowerVision Tuning
Goodson HD Tooling Manufacturer
Maxton Mile World Record
4500 sq ft. facility
OVER 35 YEARS OF H-D ENGINE BUILDING.
See us on Facebook.
The following users liked this post:
barrygreen (01-21-2019)