what's the hot setup on valves and springs?

[models916]

I am about to take my 333 heads to the shop this week. I will have them milled 20 thou (More than that?) to get some compression back. Should I use longer bbc valves and springs? Small block springs and valves? should I pin the stud or use screw in? If screw in, big or small block size? I will use Roller rockers but dont know what ratio or brand. Should I use 1.7 and get a bigger cam or pin the studs and use stock scorpion 1.75? Lots of options here, lets hear some opinions and preferences. I will be cruising and Hot Rodding, not racing. As long as I am buying parts I might as well get the free HP from the right parts. I will port match the heads first. What am I forgeting? Thanks guys

 

[Mr.Jimmy]

What are you doing??

Before you tell us all of this, one would want to know what block your using..if its a car or truck. What pistons are you using??? There isn't much of a need to mill down heads...then you run into angle problems with the intake and such.

What is your plan....or objective with this motor for power and size of a car......

 

[models916]

333 heads have a chamber

333 truck head has a chamber. Going on a 348 block .60 over, 409 crank, 6.135 rods, 11.5 pistons. HOT ROD not racer. Not sure about cam and final compression yet. Will probably take a minimum deck cut to square it all up. thanks

 

[W Head]

333 heads

I used truck heads on my 348, had 11 1/2 to 1 pistons and wanted to drop the compression to run on the sorry gas we have today. I used Manley SS BB Chevy valves. 1.80 exhaust and 2.19 intake, but you have to cut the intake valve to 2.08. That is all you have room for, they almost touch. I used BB Chevy Comp Cam valve springs, 7/16 screw studs and Scorpion 1.75 roller rockers. Ported and polished the heads, everything worked good for me, used double valve cover gaskets or the rockers would rub the inside of my Offy valve covers.

W Head

59 El Camino 348, 3-2s
59 Impala 409, 2-4s

 

[Mr.Jimmy]

What I was getting at is if your using a car or truck block. Using bigger pistons in a truck block will lower the comp. by what....1-1.5 points?? Also with your pistons, did you move the piston pins up for the longer rods?? These are things you have to think about with valves smashing your pistons.

 

[models916]

car block

Car block, releif in piston as nec. to clear valves. I am also wondering about pushrod size. should I enlarge hole to 3/8 size or run 5/16 chrome moly? I cant believe how different the W motor is from what I am used to building (sm blk). Thanks to everybody here I am getting answers before I spend the money. Thanks again, keep it comming. MIKE

 

[Skip FIx]

Valve spring choice and coil bind are a little limited for stock 690 head installed height. I don't know the installed 333 setup I would guess short also. Depends on lift of the cam you plan on. Longer BBC valves can increase that but will need a different length pushrod. Also since they use a canted valve head their intakes are shorter than the exhaust and 409s are the same. 0.100 longer intakes are common and easy to get . 1.800 and longer give alot more good valve spring choices.
In my experience checking pushrod actual length is important anyway. Chrome moly 5/16 pushrods are way stronger than old 3/8 stock type and can handle. My Pontiac with a roller spring pressures uses that diameter. Smaller diameter pushraods have less valve train weight, a problem for our 3/8 stem diameter valves. You want the rocker arm centered on the valve tip at half lift. Block decking, head milling, depth of valve seat,valve length as well as rocker used all affect optimum pushrod length.