Author Topic: non adjustable to adjustable rockers lift changes  (Read 1701 times)

0 Members and 1 Guest are viewing this topic.

fryedaddy

  • Hero Member
  • *****
  • Posts: 1252
    • View Profile
non adjustable to adjustable rockers lift changes
« on: August 26, 2017, 10:55:02 AM »
does it change the lift of a cam when you go up on the rocker ratios,if so how much?
1966 comet caliente 428 4 speed owned since 1983                                                 1973 f250 ranger xlt 360 4 speed papaw bought new

My427stang

  • Hero Member
  • *****
  • Posts: 3929
    • View Profile
Re: non adjustable to adjustable rockers lift changes
« Reply #1 on: August 26, 2017, 11:28:40 AM »
1.73% difference not assuming differences in pushrod angle, etc.  That is an ironic number given the rocker ratio LOL

Using lobe values, if you have a .330 lift lobe, .330*1.73 = .571, with a 1.76 rocker, it'd be .581

Using percentage difference, .571 * 1.0173 = .581 as well

Keep in mind that affects the entire curve, so it functionally adds duration at the valve too.  The valve will be open the same amount at .050 with hyd rockers as it will be at .0491 lobe lift with 1.76 adjustables.  Not significant IMHO, but technically it does hang the valve open slight longer
---------------------------------
Ross
Bullock's Power Service, LLC
- 70 Fastback Mustang, 489 cid FE, Victor, SEFI, Erson SFT cam, TKO-600 5 speed, 4.11 9 inch.
- 71 F100 shortbed 4x4, 461 cid FE, headers, Victor Pro-flo EFI, Comp Custom HFT cam, 3.50 9 inch

fryedaddy

  • Hero Member
  • *****
  • Posts: 1252
    • View Profile
Re: non adjustable to adjustable rockers lift changes
« Reply #2 on: August 26, 2017, 05:23:43 PM »
thanks for the info,i dont know if you can hear or feel the differences but after going to adj. rockers it seems like my engine dont smooth out till a little higher rpm.if that makes sense.
« Last Edit: August 26, 2017, 05:25:42 PM by fryedaddy »
1966 comet caliente 428 4 speed owned since 1983                                                 1973 f250 ranger xlt 360 4 speed papaw bought new