Valve Springs......

[mcmillal]

Back in September I posted some numbers with regards to 1/4 mile times at the track. I was having a problem around 5000rpm with some hesitation. Falcon Fanatic indicated that the problem might be valve float. So I looked into it. With my engine build, everything said I should be using valve springs rated between 90-110 lbs. I checked mine and they were only about 50-55lbs. I decided to change them mostly because I was curious. I installed springs rated about 105lbs. BIG difference! No problems running right up to 5600rpm. The softer springs were fine for day-to-day driving, but....well....I have to find out the full potential of mine I6 don't I. It's too late in the season to test at the track, so the official numbers will have to wait until next year. Maybe I'll do some G-Tech runs for kicks.

............Cheers, Alex

 

[Anonymous]

is spring replacing somehting I can do in my driveway?

i mean, is it hard? special tools needed?

and where did you get them? jegs is so hard to navigate....

 

[addo]

It takes a fair amount of grunt to press those springs down. You should really only spring a little over what you need. Extra pressure will wear seats, cams, lifters faster. Cam manufacturers are often guilty of overspecifying the springs as it guards against idiots over-revving the motor, to a degree. Crow do a set of single springs that is rated up to about 550 thou lift. I'd use them before doubles recommended by places like Clifford.

Cheers, Adam.

 

[simon]

is spring replacing somehting I can do in my driveway? i mean, is it hard?

1) yes and 2) no

special tools needed?

yup. Get yourself a valvespring compressor, or maybe the local shop borrows you one.

remove air cleaner, valve cover and every hose thats in your way. Then, unbolt the six pedestal mounts holding the rocker arm assembly in place. Remove rocker arm assembly. With the head still in place, work on one cylinder at a time. You´ll need to pump up the cylinder with compressed air to keep the valve in place (hook it up to your spray gun compressor), otherwise it´ll fall into the cylinder once you removed the valvekeepers.

I know of some guys who stuffed some rags into the cylinder through the spark plug hole, then turned the crank by hand to put it in TDC to keep the valve up. Though this might work, I wouldn´t recommend it.

 

[Anonymous]

so this is perfect to do when changing valve seals....as it seems to be same process...

guess I will wait for head swtich

 

[cfmustang]

That is when I had mine changed. I was putting in the larger valves and new seats so I figured why not. Definatly easier to do it all at once.

 

[Lazy JW]

I know of some guys who stuffed some rags into the cylinder through the spark plug hole, then turned the crank by hand to put it in TDC to keep the valve up. Though this might work, I wouldn´t recommend it.

A few feet of nylon cord such as starter rope for a lawn mower works great!
Joe

 

[CZLN6]

Howdy All:

Chaz- to add to Simon and Joe's advice on changing valve springs with the head on the engine.
*When using the nylon rope trick, remove all the spark plugs to make positioning the piston of the cylinder you're working on easier. Once the rope has been feed into the cylinder through the sparkplug hole move the piston up to snug the rope against the valve faces. Be sure to remove the rope before moving to the next cylinder. Nylon rope is less obsorbant then cotton rope.
*do the valves on one cylinder at a time.
*on an engine that has some miles on it, it is sometimes difficult to seperate the keeper halves. A magnet is a handy tool to have handy.
*this is the time to change valve stem seals- even if they aren't currently passing oil. It's cheap insurance.

Adios, David