When Only 2.08 Valves Will Do
Tips on LS1 Valve Insert Removal
In those maximum effort situations where the full flow potential of unmodified 2.08 intake valves is desirable, the stock LS1 seats must be replaced. Fred says you never want to use a cut-off wheel or Dremel tool to slice the seat for removal. “It takes a surgeon’s touch, and even then you can do irreparable damage to the head.” The right way involves placing the head in a seat-and-guide machine – Superior uses highly-regarded Serdi equipment – and employs a properly-sized carbide seat cutter to eliminate the stock seat insert. The trick is to cut into the insert slowly. At some point, the insert will weaken and lose its press-fit in the head. Then it’s a simple matter of gently prying it loose. You can continue machining the head’s valve seat pockets to accept the larger seat inserts to suit the 2.08 valves.
An alternate method is to find a valve that is smaller than the seat insert but shares the same stem diameter. Fred drops the valve into the valve guide making sure the head is small enough to slide all the way through the inside diameter of the valve seat. He wants the valve head below the seat insert, not resting on it. Then he welds the valve and seat together using care not to spatter the head or concentrate heat near the spark plug hole. The welding process pulls the seat away from the head so it loses its press fit. The junk valve can now be used as a driving tool to work the seat out of the head. The advantage to this technique is that it doesn’t alter the dimension of the factory-machined valve seat pockets in the head so a stock-sized replacement seat insert can be used if desired. The only disadvantage is the need to repeat the welding process for each seat and for several sacrificial valves.
Superior Automotive is one of Southern California’s leading high performance service facilities. Experts led by Joe Jill staff the fully equipped machine shop, engine assembly room, chassis dyno and 1,500 horsepower engine dyno. They welcome out-of-state business.
Sources |
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| Champions Choice, Inc 800-322-4491 |
Manley Valves 732-905-3366 manleyperformance.com |
| Superior Automotive, 714-503-1880 superiorautomotive.com |
