Is this the correct book for small blocks?
@Dale Davies
Since your quoting me….
Paragraphs are an excellent idea. ;)
I would seriously consider an upgrade to higher ratio rockers.
Why? Making use of an LA cam in a Magnum is an upgrade in .1 already which should have you seriously reconsidering the exact cam specs being used. Going to a 1.7 rocker further exaggerates the issue.
To bring in one more item, the total lift of what ever the value may be, at what point does the head stop or stall at flowing air?
This may mandate a spring upgrade as well.
This is not exactly true depending on the valve lift.
Any cam change should have fresh new springs to match what’s the valve is lifted at.
Check the installed height. If it is around 1.8", you can use Chev LS beehive springs. You would have to source retainers to fit your keepers. Beehive springs perform better at controling the valve and spring harmonics/resonant frequencies which can enable valve float.
Absolutely, LS not being absolute. OAL valve length should be considered carefully.
There are millions of LS engines in bone yards to source good springs from for little cost.
Dumb move using used valve springs. New ones are cheap and fresh OOTB
Spend on what is important,
And your mentioning used valve springs, retainers, locks and valves from a junkyard?
good reliable roller rockers.
A worthy investment for their accurate ratio over LA rockers.
Has anyone tested Magnum rockers?
How much power is the rocker worth even at the same ratio?
How much power is the added ratio?
Isn’t it easier to get a cam ground at the desired lift rather than exploit it via a rocker ratio?
A Cam intensity is increased with a change in rocker ratio. Is there not a lobe available to match or exceed a rocker change?
At what point is the valve opening speed to much or of no more benefit?
If considering removing the heads to touch up the valve job going to LS valves can be considered. This would require replacing the guides to fit the 8mm stems,
What size are Magnum valves stems?
The LS valves do not wear much so you could possibly use the valves, springs, retainers and keepers from heads removed at a Pick n Pull yard for not much more than peanuts.
Why do LS valves wear less and again you’re buying cheap used parts over fresh springs retainers and locks? Saving money at what other expense?
The port floor is a dead area to speak of, so just remove casting imperfections. Inexpensive valves and some carbide burrs and 80 grit for the diegrinder could get you more than you hope for with high ratio rockers. Still very reliable and drive like it came off the showroom floor.
Reshaping the port floor is a bad idea? No laying it back?
A quite from his second post FWIW
My REAL goal is to build my 360 to have at least 300 HP,
As I stated above, the post suggestions will do the trick.
Zero need for anything above.
Thanks