Mercruiser 420 - Valve Adjustment
06-15-2021, 01:54 PM
#1
Registered
Thread Starter
Mercruiser 420 - Valve Adjustment
Does anyone have the appropriate valve lash/adjustment for the Crane valvetrain on the 420 mercs? I am picking up my cylinder heads from the machine shop tomorrow and was hoping someone has the information handy. I am reusing the stock rockers, lifters, pushrods, etc.
06-15-2021, 04:25 PM
#2
Registered
iTrader: (1)
Crane has always stated 3/4 to
one turn therefore half to three quarter is fine too
one turn therefore half to three quarter is fine too
Last edited by SB; 06-15-2021 at 04:29 PM.
The following 3 users liked this post by SB:
06-15-2021, 05:19 PM
#3
Registered
Thread Starter
06-15-2021, 11:01 PM
#4
Charter Member # 55
Charter Member
Adjusting them before you install the intake manifold is easier to see/feel 0 lash. 3/4 turn is about perfect for Crane cams and will give about .040 of preload.
The following 2 users liked this post by Griff:
distantthunder (06-16-2021), TomZ (07-02-2021)
06-16-2021, 07:53 AM
#5
Registered
Thread Starter
Adjusting them before you install the intake manifold is easier to see/feel 0 lash. 3/4 turn is about perfect for Crane cams and will give about .040 of preload.
https://www.youtube.com/watch?v=8ROU7D-6meY
https://www.youtube.com/watch?v=8ROU7D-6meY
The following users liked this post:
Griff (06-21-2021)
06-21-2021, 09:06 AM
#7
Registered
Loosen, then tighten while spinning pushrod between fingers. Stop when you feel the pushrod has begun to feel resistance as it touches lifter and turn to desired lash.
The following users liked this post:
Griff (06-21-2021)
06-30-2021, 08:37 AM
#8
Registered
Platinum Member
well,,best way run motor motors till hear rockers are loose,,,then tighten,,,but it makes a big mess running motor with out covers..,,but i stand corrected tighten till u feel drag on push rod,,then tighten..
06-30-2021, 08:41 AM
#9
Platinum Member
Platinum Member
iTrader: (6)
If their Morels almost a full turn down..........
