Go Back  Offshoreonly.com > Technical > General Q & A
good rockers for 6000 rpm, 540CI combo?? >

good rockers for 6000 rpm, 540CI combo??

Like Tree61Likes

good rockers for 6000 rpm, 540CI combo??

Reply

Old 01-10-2015, 09:45 AM
  #21
Registered
iTrader: (2)
 
Join Date: Aug 2011
Location: bel air, md
My Boat: 1997 Donzi 27 zx & Almost 35' Fountain
Posts: 2,735
Default

Originally Posted by Full Force View Post
So many guys run aluminum though with no issues...
That's because they have the correct valve springs.
Black Baja is offline  
Reply With Quote
Old 01-10-2015, 09:48 AM
  #22
Registered
 
Join Date: Jan 2006
Location: Peoria, IL
My Boat: Center council
Posts: 2,118
Default

Originally Posted by Full Force View Post
So many guys run aluminum though with no issues...
That's because on average a rebuilt engine never gets more than 500 hrs or 20,000 miles. Show me a stock automotive application with aluminum rockers.
hogie roll is offline  
Reply With Quote
Old 01-10-2015, 09:50 AM
  #23
Registered
iTrader: (1)
 
Join Date: Jun 2009
Location: Chicago
My Boat: 38 Flatdeck
Posts: 5,970
Default

Mercury uses aluminum and ComCrap had a lot of issues with theirs.. that company is not what it used to be.



Last edited by ICDEDPPL; 01-10-2015 at 09:54 AM.
ICDEDPPL is offline  
Reply With Quote
Old 01-10-2015, 09:52 AM
  #24
Gold Member
Gold Member
iTrader: (3)
 
vintage chromoly's Avatar
 
Join Date: Sep 2011
Location: cleveland ohio
My Boat: 1977 pantera 24
Posts: 2,610
Default

Originally Posted by Full Force View Post
So many guys run aluminum though with no issues...
There's a reason why there are multiple pages of nice used jesel aluminum rocker arms on eBay.
Anyone who uses them knows they have a finite number of hours before they need replaced.
Back when lightweight valvetrains were the norm, aluminum was king. Now the emphasis is on valvetrain stability as opposed to weight.
vintage chromoly is offline  
Reply With Quote
Old 01-10-2015, 09:54 AM
  #25
Gold Member
Gold Member
iTrader: (3)
 
vintage chromoly's Avatar
 
Join Date: Sep 2011
Location: cleveland ohio
My Boat: 1977 pantera 24
Posts: 2,610
Default

Originally Posted by ICDEDPPL View Post
Mercury uses aluminum.
What's their recommended service interval?
vintage chromoly is offline  
Reply With Quote
Old 01-10-2015, 09:56 AM
  #26
Registered
iTrader: (2)
 
Join Date: Aug 2011
Location: bel air, md
My Boat: 1997 Donzi 27 zx & Almost 35' Fountain
Posts: 2,735
Default

Originally Posted by vintage chromoly View Post
There's a reason why there are multiple pages of nice used jesel aluminum rocker arms on eBay.
Anyone who uses them knows they have a finite number of hours before they need replaced.
Back when lightweight valvetrains were the norm, aluminum was king. Now the emphasis is on valvetrain stability as opposed to weight.

That's sorta true. Today's theory is cam side weight doesn't matter valve side light as possible. Pro-stock still uses aluminum arms.
Black Baja is offline  
Reply With Quote
Old 01-10-2015, 10:01 AM
  #27
Gold Member
Gold Member
iTrader: (3)
 
vintage chromoly's Avatar
 
Join Date: Sep 2011
Location: cleveland ohio
My Boat: 1977 pantera 24
Posts: 2,610
Default

Originally Posted by ICDEDPPL View Post
Mercury uses aluminum and ComCrap had a lot of issues with theirs.. that company is not what it used to be.


I agree that comp cams is entry level performance gear. That arm pictured is a cast piece and really not more than a small step up from OE. Back story on the failure? Was too much asked of that arm? Was the setup right?
vintage chromoly is offline  
Reply With Quote
Old 01-10-2015, 10:01 AM
  #28
Gold Member
Gold Member
Thread Starter
iTrader: (5)
 
Full Force's Avatar
 
Join Date: Oct 2005
Location: Olmsted Falls,Ohio Marblehead,Oh
My Boat: 87 Cigarette Hawk
Posts: 10,496
Default

Originally Posted by ICDEDPPL View Post
Break out the credit cards and go shaft rocker you pu$$!.

HAHHAHA suuuuuure!!
Full Force is offline  
Reply With Quote
Old 01-10-2015, 10:04 AM
  #29
Gold Member
Gold Member
iTrader: (3)
 
vintage chromoly's Avatar
 
Join Date: Sep 2011
Location: cleveland ohio
My Boat: 1977 pantera 24
Posts: 2,610
Default

Originally Posted by Black Baja View Post
That's sorta true. Today's theory is cam side weight doesn't matter valve side light as possible. Pro-stock still uses aluminum arms.
I get that.
Pro stock is a completely different animal. I'm sure they cycle those arms out after a few passes.
This is an endurance application.
vintage chromoly is offline  
Reply With Quote
Old 01-10-2015, 10:05 AM
  #30
Gold Member
Gold Member
Thread Starter
iTrader: (5)
 
Full Force's Avatar
 
Join Date: Oct 2005
Location: Olmsted Falls,Ohio Marblehead,Oh
My Boat: 87 Cigarette Hawk
Posts: 10,496
Default

Originally Posted by Black Baja View Post
That's because they have the correct valve springs.
I am probably going with new heads set up by Bob M..... I know they will be right..and worse case mine were redone last summer totally also and mine are good, but want a better head.
Full Force is offline  
Reply With Quote

OSO Sponsor
OSO Advertiser
OSO Advertiser
OSO Advertiser