Valve spring change in car procedure tips ?

[stinger]

going to change valve springs on my 440 soon. I have a good air compressor,valve spring compressor and was just looking for some tips on how to makes this go as smooth as it can. things like how much air pressure you use,piston position, etc.
Thanks!

[Oldschool]

90 psi or more will hold the valves closed easily enough. I have always just pulled up number 1 cylinder to TDC on the firing stroke and pressurize that cylinder. Swap the valve springs, rotate the crank 90* and go to number 8 and repeat the process through the complete firing order. 1-8-4-3-6-5-7-2 and you are done.   

[Chryco Psycho]

usually the air pressure will force the piston to the bottom of the bore so position really doesn't matter . I have the Mancini spring compressor , best I have found for changing springs on the engine . tap the retainer on one side with a hammer to loosen the retainer form the locks , use a magnet to get the locks in & out

[Strawdawg]

X2...and because I always expect the worst, I cover up the oil drain back holes so I cannot drop a lock down one by accident.  I always use a magnet and I have never dropped one but Fate always seems to kiss me if I tempt her...

[tommyg29]

I just changed some valve seals on my 440.
I used rope pushed up into the plug holes to hold up the valves. I like this method if you want to or need to play with the valves at all, like checking for play etc. You will require a magnet with this method to pull the valve stem all the way up when reinstalling. Of course you can also use the magnet on the keepers.
Also, the cheap store bought compressor I used didnt work well on my double spring setup. It BARELY held the inner spring in place, and several times the inner spring popped off when I tried to reinstall them. Plus it gave my fingers/grip a real workout.
If you have arthritis in your fingers you will have trouble, and if you dont have arthritis, you will after doing this a few times

[stinger]

Thanks everyone. I'm not expecting it to be to much trouble but wasn't sure on air pressure and didn't know you have to go in the order of the firing order.

[Chryco Psycho]

you do not have to work in firing order , the air pressure will keep the valves closed no matter what order you work through

[stinger]

just an update,changed my springs over the weekend,easy job. now she revs up to 6 grand no probs. limiting factor is now my nerve LOL.

[cudabob496]

just an update,changed my springs over the weekend,easy job. now she revs up to 6 grand no probs. limiting factor is now my nerve LOL.

will the hydraulic lifters work at 6000 rpm?

[stinger]

why wouldn't they? had a 340 that would climb easily past 7 grand,my 440 I think 6500 will be my limit.

[cudabob496]

why wouldn't they? had a 340 that would climb easily past 7 grand,my 440 I think 6500 will be my limit.

I've just read that some hydraulic lifters (due to their design) cannot handle high rpms. Creates
a potential for valve train failure.

Also read that depending on engine, stiffer springs will require better pushrods, see below:

Tech Question

Spencer S., Ovid-Elsie, MI, 1978 Chrysler Cordoba, 400

What is the Redline for a 1978 400 Big Block?

Stock, the valve spring are good to about 5,200 RPM. But the basic short block is safe to well over 6,000. Pin me down, and I'd say something like 6,250, without any component upgrades. But you'd need better (stiffer) valve springs to do this, and the stiffer springs would then require better pushrods.

Rick

[stinger]

well the car pulls to 6k no prob  now when before I had the start of valve float at 5200,was a problem with the 3:91 and 26" tire I have. I probably will set the shift light more to 5800,seems to be the happy place for my car. my 340 had crane valvetrain and pushrods with rhoads lifters,this engine I have no clue what lifters and pushrods but it ramps up really fast with the lunati 303 in it.

[Strawdawg]

Lunati shows the top end of that cam as being 6200 rpm.  That assumes you are running the correct springs with it and don't have retainers and push rods made out of lead. Flat tappet hydraulic lifters approach 7000 rpm.  Hydraulic roller lifters usually top out around 6000-6400 rpm depending upon the lobe design and the cam (rev) kit installed.

I would shift it where it runs the best for your particular combo

[stinger]

and I have stock rocker's so that pushes the limit down a bit.

[Strawdawg]

maybe...they are usually not too heavy