LS3 vs L92 heads (valves)
Interesting....So now I have a slightly larger combustion chamber and a little loss of compression. Are the 823's and 821's 68cc or 70cc?
I have a sent of Lunati High RPM lifters that I plan to run in this motor. It calls for .035-.040 preload and am thinking I should run different length pushrods or adjustable rockers.
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I was running stock LS3 valves for years. Never had any issues.
If I needed to get valves I would not get GM valves.
The Manley race master solid stainless are a superior piece with a better valve angle which means more flow.
Finding a good machine shop to cut the seats apparently is a very thing to do and picks up some power.
If I needed to get valves I would not get GM valves.
The Manley race master solid stainless are a superior piece with a better valve angle which means more flow.
Finding a good machine shop to cut the seats apparently is a very thing to do and picks up some power.
For longevity, I’d trust stock GM valves over aftermarket. I assembled my L92 heads with new stock GM stainless intake valves from the LSA, and stock GM inconel exhaust valves from the LY6. Going in front of an A6 trans, so won’t rev past 6k.
There is always lighter, but I’m going for +100k mile durability, and if I pressurize it later, then I know the valves are ready.
There is always lighter, but I’m going for +100k mile durability, and if I pressurize it later, then I know the valves are ready.
Last edited by FormulaBoat; May 29, 2019 at 09:27 PM.
TECH Addict
Joined: Sep 2010
Posts: 2,898
Likes: 467
For longevity, I’d trust stock GM valves over aftermarket. I assembled my L92 heads with new stock GM stainless intake valves from the LSA, and stock GM inconel exhaust valves from the LY6. Going in front of an A6 trans, so won’t rev past 6k.
There is always lighter, but I’m going for +100k mile durability, and if I pressurize it later, than I know the valves are ready.
There is always lighter, but I’m going for +100k mile durability, and if I pressurize it later, than I know the valves are ready.
Not sure about the LSA engine though.
Manley or Ferrea are stronger.
The solid stainless stainless would be the most durable.
But if you are running crazy boost, you may even need the high end exhaust valves so they can live
