Valve seat question
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Joined: Jul 2005
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From: Tn
Valve seat question
Just to make you think what is this guys doing with a corvette engine apart...Is there supposed to be hardened valve seats on the intake valves, I can see the inserts on the exhaust, but not on the intake? Are the valves seated into the cast head? -this is a 1970 LT1 350.
Thanks in advance?
Thanks in advance?
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1970 LT-1s do not have valve seat inserts on either the exhaust or inlets. The seats are "integral" to the head - just ground into the casting - and are not hardened.
The LT-1 was designed for 99 RON leaded fuel. Even if rebuilt today, there is no need for either seat inserts or hardening of integral seats if you keep the valves adjusted properly at .016/.023" cold and adjust the inlets at 90 ATC and the exhausts at 90 BTC.
With typical production machined decks and head surfaces and a .038" composition head gasket, the actual true CR with the OE domed pistons should be no more than about 10.5:1, and it will operate okay on 93 PON unleaded premium.
Duke
The LT-1 was designed for 99 RON leaded fuel. Even if rebuilt today, there is no need for either seat inserts or hardening of integral seats if you keep the valves adjusted properly at .016/.023" cold and adjust the inlets at 90 ATC and the exhausts at 90 BTC.
With typical production machined decks and head surfaces and a .038" composition head gasket, the actual true CR with the OE domed pistons should be no more than about 10.5:1, and it will operate okay on 93 PON unleaded premium.
Duke
Last edited by SWCDuke; Feb 26, 2006 at 08:03 PM.
