briancb1

It looks like some chamber work, but did they remove that intake bowl wing?

0C_Williams@RPM

yes, typo


what is interesting to me is that guide wear on the rest of the LS family is nearly non-existent.

in this case, it comes close

0C_Williams@RPM

no, we do not remove the intake bowl ring.

the chamber work you see is simply blending of the entry and exit of the valve seat area,

FrankTank

How many LS7's that you've seen, or worked on have failed as a result of Guide Wear? Do you keep any data on the LS7's you work on that have Guide Wear? Do you keep track of MY of these LS7s?

Just curious.

0C_Williams@RPM

we've done over a dozen engines where the exhaust valve head ended up detached from the valve stem. don't know the root cause of the failure but seems logical that the once the valve stem wears and the valve heads starts wobbling around the seat, there is going to be an issue.

we maintain data on all our cylinder heads and engines, yes.

we see 3-4 sets of LS7 heads each month. as the mileage and track use increases so does the guide wear.

FrankTank

Thanks for the information. On those failures you saw (over a dozen) were the guides worn, or were guides measured? I assume no since you said you don't know the Root cause? Also, were they all stock motors?

Thanks again for sharing the information. Any other head data you can share would be great of course if you are ok with it..not trying to be pushy.

HoustonSVT

Thanks for the post, hope everyone does these posts when having this work done.

Mike McGinnis

What's something like this run price wise?

0C_Williams@RPM

$2,695 ...car will be in the shop for 3-5 working days

Parts Include

CHE Valve Guides
SS exhaust Valves
Dual Springs, ti Retainers, Steel Spring Bases
Stem Seals
Head Bolts
Head Gaskets
Comp Trunnion Kit

Machining & Labor

Install guides and hone to size
Comp Valve Job
Light "bowl porting"
Mill & CC
Clean & Assemble
Upgrade Rocker Arms
R&R Heads
__________________

'06 Quicksilver Z06

You do anything to the intake valves?

0C_Williams@RPM

yes,

1 - cleaned and visually inspected for wear and surface finish
2 - checked for face runout
3 - stems polished if required
4 - diameter checked

'06 Quicksilver Z06

$2,695 is a great deal for all of that.
Very solid package it seems. You got your springs, your trunion upgrade, valve upgrade, and the intake valves taken care of as well as the guides. Plus the bolts and the gaskets, and the other extras. That's a heck of a deal installed.

I know you deal a lot with the road racing guys out there, is this the package that they generally run as far as their cylinder head work?

0C_Williams@RPM

yes, same guide/valve combination - but the road race package gets our full CNC work ($550), different valve springs and 65 cc chambers.

'06 Quicksilver Z06

Well, you have put together a nice package here and at a great price.

john_g_46

I have a CNC Mil in my garage and was considering doing this myself. so...
Are the valve guides pressed in or cast in place?

0C_Williams@RPM

thank you

0C_Williams@RPM

they are pressed in.

if you do this yourself here's what we do. BTW, other methods work, it's just what we do.

1-remove guides
2-clean heads
3-preheat heads to 255° F
4-dry ice new guides
5-drop in place
6-let heads cool
7-hone guides to size
8-machine seats

AzDave47

This is not something I would ever try, but really appreciate a top vendor sharing this info. It may be common knowledge in "the trade" but certainly good info for the rest of us as it gives us a better technical understanding.

This a totally different approach to us than GM has been doing.

john_g_46

Remove guides sounds like an interesting 1st step...Do you heat up the heads first? Do they press out from the rocker arm side of the head?

0C_Williams@RPM

they press out from the valve side. we use a pneumatic press that applies force with impact. they press out easily without galling as long as you maintain proper geometry.