How do I?, Install new valves
Thread Starter
Le Mans Master
Joined: Jan 2007
Posts: 9,844
Likes: 33
From: S. FLA :: Professional Devil's Advocate
How do I?, Install new valves
I'm replacing the intake & exhaust valves on my heads with the same length, diameter stuff. (Reason being one intake valve tip was slightly dinged up, so I'm just replacing them all to be consistent).
Unfortunately there is a lack of information on the subject and I couldn't find any machines shops/performance shops that would even do it. I have the GM service books but they're somewhat useless on the subject, the following is the entire set of directions:
Now the thing is, this is labeled under a section where they're replacing the valves due to actual valve damage and/or reaming the valve bore. I'm not doing any of that so do I need to grind the seats? A friend who used to work on other types of engines mentioned something about a paste stuff that you would use to grind between the valve and valve seat to get a good seal. GM on the other hand mentions some serious grinding via a tool or machine.
Any help would be appreciated.
Unfortunately there is a lack of information on the subject and I couldn't find any machines shops/performance shops that would even do it. I have the GM service books but they're somewhat useless on the subject, the following is the entire set of directions:
Inspect for a loose valve seat (9 or 11) in the cylinder head (1). The valve seat has an interference fit to the cylinder head.
Clean the valve guide (7) bores with a suitable tool. Remove all carbon or dirt from the bores. The valve guide must be clean for the seat grinding tool to obtain proper results.
Grind the valve seat. The recommendations of the manufacturer of the equipment should be followed carefully to obtain the proper results. Regardless of what type of equipment is used, it is essential that valve guide bores be free from carbon or dirt to ensure proper centering of the tool pilot in the guide.
Inspect the valve seats.
The valve seats should be concentric to within 0.05 mm (0.0021 in) total indicator reading.
If the valve seat has been ground, it may be necessary to shim the valve spring to attain the proper spring installed height. Refer to Cylinder Head Assemble .
Clean the valve guide (7) bores with a suitable tool. Remove all carbon or dirt from the bores. The valve guide must be clean for the seat grinding tool to obtain proper results.
Grind the valve seat. The recommendations of the manufacturer of the equipment should be followed carefully to obtain the proper results. Regardless of what type of equipment is used, it is essential that valve guide bores be free from carbon or dirt to ensure proper centering of the tool pilot in the guide.
Inspect the valve seats.
The valve seats should be concentric to within 0.05 mm (0.0021 in) total indicator reading.
If the valve seat has been ground, it may be necessary to shim the valve spring to attain the proper spring installed height. Refer to Cylinder Head Assemble .
Any help would be appreciated.
Pro
Joined: Oct 2005
Posts: 738
Likes: 2
From: Richmond VA
The paste they are referring to is "lapping compound". It is used to put a final finish on valve seats and insure complete contact with the back side of the valves. I find it hard to believe that the local NAPA machine shop or any other machine shop won't replace your valves.
Its pretty average stuff.
Its pretty average stuff.
Melting Slicks
Joined: Feb 2006
Posts: 2,172
Likes: 104
From: Des Moines Iowa
Do what you want, but if it were me, I'd simply replace the single intake valve that was bad, assuming you have an otherwise good fairly low mileage LS engine. Believe you'd need to have the new intake valve and valve seat ground, to ensure good seal, and then as previously stated, you could "lap" in this one new intake valve.
