Tapping for roller cam

Discussion in 'Technical' started by justin has a 74, Jul 29, 2010.

  1. justin has a 74

    justin has a 74 Maverick bandit official

    Joined:
    Sep 18, 2008
    Messages:
    3,758
    Likes Received:
    9
    Trophy Points:
    112
    Location:
    kentucky
    Vehicle:
    74 maverick /71 grabber /72 maverick
    Making my old green motor into a roller motor wanabee.
    Got the kit and it says to go ahead and drill and tap. Thats it?:16suspect

    Am i going to have any problems with the lifter guides not being at a certain level? (difference in lifter valley height, and no bump for the spider to sit on)


    Just trying to be causious, dont want to ruin a roller cam (again)
     
  2. ShadowMaster

    ShadowMaster The Bad Guy

    Joined:
    May 15, 2005
    Messages:
    1,156
    Likes Received:
    1
    Trophy Points:
    95
    Location:
    The ShadowLands
    Vehicle:
    1969 1/2 Maverick
    So.....they give you instructions. You actually READ them. Then you don't believe them?
     
  3. justin has a 74

    justin has a 74 Maverick bandit official

    Joined:
    Sep 18, 2008
    Messages:
    3,758
    Likes Received:
    9
    Trophy Points:
    112
    Location:
    kentucky
    Vehicle:
    74 maverick /71 grabber /72 maverick
    I just cant believe its that easy, better safe then sorry.
     
  4. Bryant

    Bryant forgot more than learned

    Joined:
    Aug 7, 2007
    Messages:
    6,538
    Likes Received:
    153
    Trophy Points:
    203
    Garage:
    1
    Location:
    San Diego
    Vehicle:
    71 Maverick
    are you useing a reduced base circle cam?
    thats what you need to make the stock roller lifters work in a non roller block. if thats what your useing then yes you just need to drill and tap holes in the block to bolt the spider plate down to. if your not using a reduced base circle cam you will have problems with the lifters in there bores.
     
  5. scooper77515

    scooper77515 No current projects.

    Joined:
    Jun 30, 2004
    Messages:
    14,672
    Likes Received:
    73
    Trophy Points:
    233
    Location:
    Issaquah/Grand Coulee, WA
    Vehicle:
    Fresh out of Mavericks
    So that explains the reduced base circle on my cam. Didnt know it had it til the pushrods ended up being wrong by .065 or something like that. I ended up using lashcaps to fill in the gap.

    My block was a 5.0 and had two nipples raised in the lifter valley. I drilled and tapped those and bolted everythinv down. Use locktite so you dont wiggle something loose in a couple months.
     
  6. 74 GRABBER

    74 GRABBER Member

    Joined:
    Oct 17, 2005
    Messages:
    792
    Likes Received:
    1
    Trophy Points:
    90
    Location:
    Peoria AZ
    Vehicle:
    1974 grabber, 1995 mustang GT, 1967 mustang coupe, 1956 Caddilac sedan Deville
    I thought the lifter bores and spider bosses were on the same revision on the block. Shouldn't you be able to drill and tap the bosses and run roller cam and lifters without the use of a reduced base circle cam?


    Justin what year is your block?
     
  7. mean_maverick

    mean_maverick Senior Member

    Joined:
    Aug 29, 2005
    Messages:
    7,312
    Likes Received:
    11
    Trophy Points:
    153
    Location:
    Irvine, Kentucky
    Vehicle:
    '73 4dr
    correct. if it already has the bosses for the "spider" bolts then you wouldnt need a reduced base circle cam because it's already a roller block (just didnt have the roller lifters from factory)
     
  8. Bryant

    Bryant forgot more than learned

    Joined:
    Aug 7, 2007
    Messages:
    6,538
    Likes Received:
    153
    Trophy Points:
    203
    Garage:
    1
    Location:
    San Diego
    Vehicle:
    71 Maverick
    ok. it helps when all relevant info has been given.
     
  9. justin has a 74

    justin has a 74 Maverick bandit official

    Joined:
    Sep 18, 2008
    Messages:
    3,758
    Likes Received:
    9
    Trophy Points:
    112
    Location:
    kentucky
    Vehicle:
    74 maverick /71 grabber /72 maverick

    Its a 1980 block. No spot for the roller cam bolts:cry:

    Any more info on these fansy cams your talking about Bryant?:16suspect
     
  10. maverick75

    maverick75 Gotta Love Mavs!

    Joined:
    Mar 31, 2005
    Messages:
    9,014
    Likes Received:
    15
    Trophy Points:
    172
    Location:
    Riverside, California
    Vehicle:
    The mav is gone but i'm still here!
    Justin do a search. Theres 3 threads full of all this info. I remember reading up on this subject. Also an alternative to the reduced base circle cam is to use a set of linked lifters. But you`ll probably piss your pants when you see the price. Lol
     
  11. maverick maniac

    maverick maniac Banned

    Joined:
    Mar 13, 2009
    Messages:
    892
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    owensboro ky
    Vehicle:
    72 sprint v/8 3 grabbers 73 comet and a 77 comet race car
    are you just a wise guy or am i just reading you wrong :huh:
     
  12. scooper77515

    scooper77515 No current projects.

    Joined:
    Jun 30, 2004
    Messages:
    14,672
    Likes Received:
    73
    Trophy Points:
    233
    Location:
    Issaquah/Grand Coulee, WA
    Vehicle:
    Fresh out of Mavericks
    He's pretty wise...:rofl:

    I mean, that is a good point.
     
  13. cdeal28078

    cdeal28078 Member

    Joined:
    Feb 18, 2005
    Messages:
    918
    Likes Received:
    1
    Trophy Points:
    75
    Location:
    North Carolina
    Vehicle:
    71 F100
    Some of the early truck 5.0's had the raised lifter bores and the bosses for the spider bolts But the tops of the lifter bores were not machined flat and have to be machined. Need to check that out I think also
    clint
     
  14. justin has a 74

    justin has a 74 Maverick bandit official

    Joined:
    Sep 18, 2008
    Messages:
    3,758
    Likes Received:
    9
    Trophy Points:
    112
    Location:
    kentucky
    Vehicle:
    74 maverick /71 grabber /72 maverick

    Some are actually tapped!!!:D


    Still searching

    " small base circle cam is where the cam's core (the round metal part of cam that the lobes and bearing jounrals are made onto) is a smaller DIA.

    You do this, not for greater lift but for rod bolt/crank to cam clearance on stroker engines.. When you add a longer stroke crank into a block that wasnt ment to hold it..

    Like a chevy 383 stroker (3.75" stroke crank into a block made for a 3.48" stroke)

    The rod bolts will hit the cam, as the piston/rod moves up the bore because the crank now pushes rods/pistons .27" (over a 1/4 inch) higher up

    By using a cam ground on a smaller core shaft, the clearance prob is gone..

    You can also grind the shoulders down on the
    tops of the rod bolts, or use aftermarket rods that are already made stroker clearanced and run a std cam"
     
    Last edited: Jul 29, 2010
  15. justin has a 74

    justin has a 74 Maverick bandit official

    Joined:
    Sep 18, 2008
    Messages:
    3,758
    Likes Received:
    9
    Trophy Points:
    112
    Location:
    kentucky
    Vehicle:
    74 maverick /71 grabber /72 maverick
    Ok i got it, thanks guys.

    Hey Bryant?
    Why didnt you just say that the lifters need to set lower and thats what the cam does?


    :p:bouncy:
     
    Last edited: Jul 29, 2010

Share This Page