How much do you gain with hollow stem valves?
01-14-2013, 09:20 AM
#21
My post was short in an effort to keep my explaination simple, and I was trying to keep it relative to the OP's question and following replys. Yes the valve train is considered in its entirety, and using all light componets never hurts. Yes valve springs have ALWAYS been matched to the cam, the cam pretty much set the baseline for the usable rpm range of the engine.
In a all out racing engine where one is trying to get every last HP and rpm from an engine, for sure run the lightest componets that you can safely get away with, for the guy wanting to hop up his street car or mild street/strip car, sourcing out light weight valves should not be on the top of the list.
In a all out racing engine where one is trying to get every last HP and rpm from an engine, for sure run the lightest componets that you can safely get away with, for the guy wanting to hop up his street car or mild street/strip car, sourcing out light weight valves should not be on the top of the list.
01-20-2013, 11:18 PM
#24
Light weight valves are definitely a plus, hold on to the power longer and take advantage of those upper rpms...plus turned down ls3 hollow stems are only a $150 adder when getting new heads...
and for reference I had the pac1521 springs good for 700 lift, they are a decent spring...
With the heavy 110 gram tfs valves the power died pretty fast around 6800...swapped out those heavy slugs and switched to 102 intake from my 92, picked up 20rwhp at peak and almost 50rwhp at 7300rpm...
Granted my lsl/lsl cam wasn't helping stability either...
With any set of TFS heads it is a no brainer until they source some lighter solid stems to put in them...also for reference my valves were 2.04" and a buddy had some tea stg 2.0 ls6 heads with 2.02" valves and they were a lot lighter at 101 grams...so I can't see why tfs uses them heavy anchors
and for reference I had the pac1521 springs good for 700 lift, they are a decent spring...
With the heavy 110 gram tfs valves the power died pretty fast around 6800...swapped out those heavy slugs and switched to 102 intake from my 92, picked up 20rwhp at peak and almost 50rwhp at 7300rpm...
Granted my lsl/lsl cam wasn't helping stability either...
With any set of TFS heads it is a no brainer until they source some lighter solid stems to put in them...also for reference my valves were 2.04" and a buddy had some tea stg 2.0 ls6 heads with 2.02" valves and they were a lot lighter at 101 grams...so I can't see why tfs uses them heavy anchors
