Changing Valvesprings With Heads Off?

[The Fixer]

Hey all,
I'm in the middle of a great debate within my own mind. I'm gonna assemble the 355 shortblock this week, and want to install it next week while I'm on Spring Break.

I'll be using World Products 58cc heads; they're currently on my 305 and only have about 25K miles on them. When I bought them, I told the vendor what my cam profile was in the 305, and they spec'd a set of springs for a max of .480 lift (that's what it says on my receipt anyway). Now, if you look at the tech specs for the World heads on their site, it says they come with springs good to .560 lift. I'm sliding a ZZ4 cam in, which is .474/.510.

SO, should I assumed they changed the springs over what they come with from World, or not worry about it and run it? :help: If I should change 'em, anyone have a budget-friendly recommendation on a set of springs, and how tough are they to change with the heads off the shortblock?

[90FormulaWS6]

they are very simple to change off the shortblock, if you have a valve spring compressor it shouldnt take you more than an hour or two to change all 16

[Tru2Chevy]

Any chance that you could contact the vendor to find out what springs they shipped on your heads?
If not, I would grab a set of springs as insurance. Better to spend a few bucks to do it now than find out that you need to change them once the engine is in the car.

- Justin

[Pampered-Z]

Springs are much easier to change with the heads off, no chance of dropping a valve into the cylinder!

Actually changing springs might be a bit more involved if you don't have the information about your current springs.

You should really find out what springs are on the heads, if your not sure what the specs are on the springs change them. Also, if that 510 lift is with 1.5 rockers and you plan to use 1.6 rockers you should really change them as you'll be close to the 560 lift ( 544 lift with 1.6 rockers, that seems too close for me!)

You need to know when they bind (lift), and also the spring pressure. Higher lift and RPM cams need additional pressure. If either bind or pressure is wrong you run the chance of sticking/floating a valve and doing allot of damage to your engine.

Also, when buying/replacing springs you will need to know and check the spring hieght, so you will need a tool to do this as well as possibly needing to change the seats/locators and retainers. ( Sorry, I would offer mine, but I lent it to a freind that moved to Texas, and so did this and a few other of my tools! - I think the tool was around $100, been a while ) See if you can borrow one?

You can go to any site such as Comp cams and search for a cam with specs close to your's and get the proper spring, retainer information for use on your heads. Many vendors sell match kits that fit in the head pockets, I would this World prod. are machined to accept the larger diameter springs, but don't ASSume!

Under 600 lift you can use a single spring so the springs and retainers should be around $200 ( retainers cost more then the springs ).

JB

[johnjzjz]

The way its done is with a spring seat micrometer ( you can also use a dial caliper ) that measures the installed height of the spring the # you get will be like 1.850, you than put spring and upper retainer in a rimac spring tester and you get the spring pounds installed, for the cams you are talking, about 100 to 120 lbs on the seat ?? dont have your cam specs, so to see what world might have speced the head out for their is an easy way to check that as well i see you are from north jersey i have all these tools ( IF ) you are mechanicaly inclined i can show you how and what to do ( i am not going to do it for you ) so the new cam you buy or have one of the lobes wont burn off on start up from to much spring pressure or retainer bottoming on the on the valve guide ----- please note if you are a mechanic and do your own work and just do not have the equiptment i can help i have a race shop and i am jammed with work but i was a young guy once with no help i know what its like jz

[The Fixer]

Justin - I bought the heads from Indy Cylinder Head, but I'm not sure they'd even have records anymore. I bought and installed 'em six years ago. :)

JB - I'll be using 1.5 roller rockers; I have them on my 305 already as well. Also, the ZZ4 is rated at 355 hp at 5200 rpm, and I will have a TPI on top, so this is not gonna be a screamer small-block - it's gonna be a torque beast that'll never see over 5500 rpm (unless I miss a shift LOL). Thanks for the info on spring sizes too. I have to look at the .pdf file I downloaded from World about these heads.

JZ - Thanks for all your great information. I am mechanically inclined, and would gladly take you up on your offer to learn how to do the work. Where is your shop located? I'm in Bergen County, about 15 minutes from NYC. Please PM me with your number and location and I'll see what we can work out.

Thanks for all the answers guys!

[The Fixer]

Well, here's the latest update.

When I pulled the heads off the 305 last week, they were pretty scuzzy inside; evidently my 'lil 305 had some blowby issues I wasn't really aware of. So, Friday I brought the heads up to the machine shop that took care of the 350 for me and he gave me a killer deal to clean the heads, replace the seals, and check the springs. Got 'em back today and they look great! Will get 'em bolted on this week and set the rest of the motor up!