Changing Valve Springs

[Cudajason]

Hey guys, I maybe over thinking this, but how straight forward is changing out the valve springs.

I have read all sorts of information on machining the heads, using a micrometer to measure the installed height, seat pressure, open pressure etc. and making sure everything the standardized...but is all that really necessary for a street engine??

Should it be as simple as popping off the springs, installing new valve seals and installing the new springs? 

Jason

[1 Wild R/T]

That depends on what springs your trying to install.... If you are sticking with a mild flat tappet cam & choose the right parts it's an easy swap... Going to a cam with .600 lift? It's gonna be a little more involved...  You should plan to measure spring heights....   

[RJChallenger]

IMO you are over thinking this process , if you  basically stay in the stock to slightly modified range . It starts to get a little more complicated when you get into the higher performance range with bigger camshafts and double springs etc. The really big lobe camshafts  and roller rockers endure a tremendous amount of pressure from heavy duty springs. Two springs sitting beside each other , install at the same height might produce different seat pressure. shimming under one spring with lower seat pressure will increase the seat pressure on the valve. the more equal the the pressure on all valves, the less strain on the valve train. the smoother it rotates.

[Chryco Psycho]

 IMO you are fine , if the engine is running OK as it is now it will be Ok after as well , once you cut the seat the valves can be reseed into the port & the stem can become too high for the hyd lifter to adjust properly .
Do you have a plan & tools to do this ?
the best tool I have used is the Mancini lever tool , it bolts down tot he pedestals & levers down on the retainer , you also need to hold the valves closed this can be done with Air or with a soft rope fed into the spark plug hole then rotate the engine over to pinch the valves closed while you swap springs & seals .

[Cudajason]

thanks guys! 

My plan is to order a Lunati Voodoo 702 cam as CP suggested...they have a kit that includes the matching springs, locks retainers and timing chain.

Engine runs fine now,  and this is pretty mild street stuff, so it should al go together fairly easily I would hope. 

I think I may pull the engine out and put new gaskets and a rear main seal in it, I have battle a steady oil leak for a few years now.  I am going to take one more look and see if I can find it, but if not, pull it out and seal it up properly!!!

To do the springs, I will rent or maybe buy a spring compressor and change them our while heads are off. Lets hope the valve guides are not shot too!!

Jason

 

[Rich G.]

If you're going through all the trouble to pull the engine and the heads I'd just send them out and get a valve job and be done with it. Watch out for that can of worms when you open it!

[RUNCHARGER]

You have to pull the heads? If you don't I'd hit it in the car, easy weekend job including the cam stab.

[Chryco Psycho]

I agree with both , if you are going to pull the heads do everything
But if the compression is even now I would I would do everything in car , even the rear main is not too bad to do

[jimynick]

Jason, I have a valve spring compressor, so if you pull the heads, come and get it. If you do pull the heads, I'd either buy the tool or have a machine shop machine the guides to take a PC style seal rather then the old umbrella ones and they can check the guide clearances then as well. Rule of thumb was that if you can feel any appreciable amount of lateral movement in the valve stem when in and up in the guide, then you should look further. 

[Brads70]

@Cudajason    If your going to pull the heads .... my buddy Darcy ( mopar parts hoarder) is cleaning out his shop, said he's listing on kijiji, 308's, head, magnum etc... and exhaust manifolds, 340, magnums etc... for cheap just to get rid of them..... Just an option. I can get you his phone number if you want

[Cudajason]

@Cudajason    If your going to pull the heads .... my buddy Darcy ( mopar parts hoarder) is cleaning out his shop, said he's listing on kijiji, 308's, head, magnum etc... and exhaust manifolds, 340, magnums etc... for cheap just to get rid of them..... Just an option. I can get you his phone number if you want

@Brads70 thanks man...I am not sure what I am doing yet, but should know this week.

What would the benefit of the 308s be?  Does he have and transmissions?

Jason

[jimynick]

Jason, I called your # and LMTCB. I just got off the phone with Brad, and called his buddy and LMTCB with him as well. Brad says he has lots of parts and I was thinking of making a run up as Brad says Darcy is sick and tired of people just calling and never doing anything about it and he's going to either sell these parts cheaply or just heave them. 

[Chryco Psycho]

Grab all of the 308 heads , I know @blown motor  needs a set , they can make 40 rwhp over the X or J castings , they are simply the best LA casting out there !

[Brads70]

@Cudajason    If your going to pull the heads .... my buddy Darcy ( mopar parts hoarder) is cleaning out his shop, said he's listing on kijiji, 308's, head, magnum etc... and exhaust manifolds, 340, magnums etc... for cheap just to get rid of them..... Just an option. I can get you his phone number if you want

@Brads70 thanks man...I am not sure what I am doing yet, but should know this week.

What would the benefit of the 308s be?  Does he have and transmissions?

Jason

No transmissions that I know of?  Neil would know what castings to look for? I have no idea.... @Chryco Psycho

[Cudajason]

Grab all of the 308 heads , I know @blown motor  needs a set , they can make 40 rwhp over the X or J castings , they are simply the best LA casting out there !

Wow. That much!!!!  Guess I better see what he wants for them.

@jimynick left you a vm, let me know what you get worked out and I will see what I can do!

Jason