Rocker Arm Install

Reply Subscribe

Thread Tools

Search this Thread

Mar 16, 2018 | 02:47 PM

MonochromeSS

Thread Starter

On The Tree

iTrader: (1)

Joined: Apr 2007

Posts: 192

Likes: 0

From: Northern IL

Rocker Arm Install

Putting my engine back together and I noticed as i tighten up my rocker arms the springs, even the ones where the valves should be closed are moving down ever so slightly.

Measured 11.25 turns with the pushrod checker, which says my rods should be 7.423 and i have 7.425 pushrods...

Is this normal?

Mar 16, 2018 | 03:29 PM

joecar

TECH Senior Member

Joined: Apr 2002

Posts: 6,080

Likes: 17

From: So.Cal.

Did you place the rocker arm mount/rail on the head first...?

Mar 16, 2018 | 03:33 PM

Jontall

TECH Fanatic

Joined: Sep 2005

Posts: 1,584

Likes: 23

From: NYC

Are you using stock lifters?

Mar 16, 2018 | 03:37 PM

MonochromeSS

Thread Starter

On The Tree

iTrader: (1)

Joined: Apr 2007

Posts: 192

Likes: 0

From: Northern IL

Stock lifters yes. After letting them sit a bit the springs extended back to normal. I think it was delay to the lifters pumping down.

Also, yes, they're on the rail

Mar 16, 2018 | 04:47 PM

big hammer

10 Second Club

Joined: May 2009

Posts: 3,427

Likes: 226

From: over dere

You need to count the turns at zero lash when checking your preload.

Mar 17, 2018 | 07:25 AM

vettenuts

TECH Senior Member

iTrader: (4)

Joined: Jul 2004

Posts: 8,092

Likes: 13

From: Little Rhody

Quote:

Originally Posted by MonochromeSS

Assuming the pushrod length is OK, yes this is normal. The lifter will bleed down a bit and the valve should close. If it doesn't, than the pushrod length is suspect. If your setup is using the stock rockers, you should be following the GM procedure to prevent driving the valve into the piston and to obtain the proper bolt preload.

Mar 17, 2018 | 12:53 PM

MonochromeSS

Thread Starter

On The Tree

iTrader: (1)

Joined: Apr 2007

Posts: 192

Likes: 0

From: Northern IL

Quote:

Originally Posted by vettenuts

This is completely what happend... Caught me off guard at first because I don't remember ever seeing anyone say anything about that but when you think about it makes total sense.

Good point on the GM procedure for piston/valve clearance, although i don't really have an issue with that because I have a TON of valve clearance because of my setup.