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Have these valve guides been cut? **pics**

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Old 01-22-2013 | 07:46 PM
  #1  
eseibel67's Avatar
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From: Kitchener, ON
Car: 1988 GTA
Engine: LB9
Transmission: T5
Axle/Gears: 3.45
Have these valve guides been cut? **pics**

Unexpected on a 1.5 year-old rebuild, but valve cover gaskets on both banks, as well as the timing cover-to-oil pan seals all have slight oil leaks and I'm going to repair them.

This is my son's car, and we are thinking about changing the cam while we are in there fixing the oil leaks:

Current: Comp Cams 08-300-8, 206/210, .450/.480 112 LSA
Change to: Comp Cams 08-302-8, 210/220, .480/.480 112 LSA

It's a minor change which usually induces comments of "it's not worth it" in terms of time and cost. Neither are a factor in this case.

General consensus seems to be that .470 is maximum valve lift with stock 14101081 casting heads. The current cam is .480 on the exhaust side, but I'm not sure if the clearance was acheived through machining or through some other means such as special retainers. Since the exhaust is o.k., my concern is the intake side, so I removed the spring and took these pics:





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Have these valve guides been cut, or are they stock castings?
Old 01-22-2013 | 09:17 PM
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Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: Have these valve guides been cut? **pics**

Probably have been.

Measure the OD of the necked-down section... if it's around .575" they're untouched; if .530" or .500", they've been worked on.
Old 01-25-2013 | 06:55 PM
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From: Philly, PA
Re: Have these valve guides been cut? **pics**

I don't often disaagree with Sofa, but those look awfully stock to me. The factory often did the old o-ring + shedder arrangement PLUS a positive seal on the guide from the late 80s-on-up. Unfortunately, the seal technology of the day was not so good so they didn't last as long as more modern seals.
Old 01-25-2013 | 08:44 PM
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eseibel67's Avatar
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Joined: Jul 2009
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From: Kitchener, ON
Car: 1988 GTA
Engine: LB9
Transmission: T5
Axle/Gears: 3.45
Re: Have these valve guides been cut? **pics**

The O.D. of the necked-down section is .575ish (cheap vernier caliper), so it's likely stock.

I found the rebuild bill from the machine shop, and the springs used were 983-16, which according to the Comp website do NOT require machine work on the heads when used with the 08-302-8 cam.

We might be o.k. with the 08-302-8 cam with the setup as is, but we still have to reseach it some more to be sure. Our long cold Canadian winter buys a lot of time to ponder.
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