LS7 valve guide wiggle : VIDEO

Reply Subscribe

Thread Tools

Search this Thread

Feb 24, 2013 | 09:26 AM

jdb8805

Thread Starter

Teching In

Joined: Nov 2001

Posts: 26

Likes: 0

From: Texas City, TX ,USA

LS7 valve guide wiggle : VIDEO

This is 2007 Z06 with 16097 miles
Spec clearance is .0012 - .0025 (as produced)
Service limit is .0037

The gauge moves a total distance of .0080 - .0100 1" above the guide on exhaust #2 EDIT: on remeasure with a more fixed location and removing the Pointed tip of dial indicator, its .0070-.0080
The gauge moves a total distance of .0050 - .0060 in the intake #2
EDIT: remeasure Zero movement on the dial indicator. Maybe .0010
What does this translate into for clearance?

Based on this book

http://books.google.com/books?id=_CQ...tput=html_text

And real world measurements of .0100 wiggle --> .003 or .004 clearance, I believe I'm right at or just below the service limit.

Last edited by jdb8805; Feb 26, 2013 at 09:59 PM. Reason: Added video

Feb 24, 2013 | 08:02 PM

jdb8805

Thread Starter

Teching In

Joined: Nov 2001

Posts: 26

Likes: 0

From: Texas City, TX ,USA

Bump...

Feb 24, 2013 | 08:08 PM

HioSSilver

10 Second Club

iTrader: (8)

Joined: Aug 2002

Posts: 6,128

Likes: 645

From: Winchester, VA

Good find. From what I have gathered it's been a guide problem and not a valve problem. Now why is the guide wearing out early?

Feb 24, 2013 | 08:10 PM

msydow

TECH Regular

Joined: Aug 2010

Posts: 462

Likes: 0

From: houston, texas

i would think they would measure a new valve stem and measure i.d. the of the guide then subtract the two to find the clearance.

Feb 24, 2013 | 08:40 PM

jdb8805

Thread Starter

Teching In

Joined: Nov 2001

Posts: 26

Likes: 0

From: Texas City, TX ,USA

Heads are still on car. Trying to determine whether clearance is bad enough to pull them.

Feb 24, 2013 | 09:04 PM

HioSSilver

10 Second Club

iTrader: (8)

Joined: Aug 2002

Posts: 6,128

Likes: 645

From: Winchester, VA

Quote:

Originally Posted by jdb8805

Heads are still on car. Trying to determine whether clearance is bad enough to pull them.

For sure it is. I would not even start it like that.

Feb 25, 2013 | 08:00 AM

jdb8805

Thread Starter

Teching In

Joined: Nov 2001

Posts: 26

Likes: 0

From: Texas City, TX ,USA

Quote:

Originally Posted by HioSSilver

For sure it is. I would not even start it like that.

I'll assume you opened the page from the google books on small block chevys and read that a wiggle of .0100 - .0150 with the valve 1/4" off it's seat translates to a valve guide clearance of .0030 or less.

Reply Subscribe