360 Cyl Head Question

[fuzzy]

Bought a set of 360 cyl heads (bridge type) at a local auction, machine work already done, valve job, resurface ect., I did not check them very well because found out when whoever did the valve job ( pos valve seats ) the valve stem height from spring seat to top of valve is very different from one valve to another, meaning spring installed height needed to be shimmed, no big deal with this, but when installing Comp Cam and lifters, the lifter preload varies from .045" to .110". Comp says .030" to .045". Some of the cyls., I can get .050 shorter push rods for but some of them at .070" for instance, a shorter push rod wont work. My question is can the bridge, where it meets the head be shimmed with washers or shim stock to bring all of them into specs? Already looked at grinding valve stems but not enough sten there, rocker would hit spring retainer. Any help on this is appreciated.

 

[tarry99]

Bought a set of 360 cyl heads (bridge type) at a local auction, machine work already done, valve job, resurface ect., I did not check them very well because found out when whoever did the valve job ( pos valve seats ) the valve stem height from spring seat to top of valve is very different from one valve to another, meaning spring installed height needed to be shimmed, no big deal with this, but when installing Comp Cam and lifters, the lifter preload varies from .045" to .110". Comp says .030" to .045". Some of the cyls., I can get .050 shorter push rods for but some of them at .070" for instance, a shorter push rod wont work. My question is can the bridge, where it meets the head be shimmed with washers or shim stock to bring all of them into specs? Already looked at grinding valve stems but not enough sten there, rocker would hit spring retainer. Any help on this is appreciated.

Fuzzy,

So do you think the seat is sunk in the head? or ground to deep?
Or has the valve / seat surface just been overground?...........If it's the valves change the one's that are needed..............
The seats in the heads can also be replaced but that is a much larger project and perhaps not cost effective...............as far as shimming the stands................not a good practice simply because first the surface your shimming to would have to be ground perfectly flat and then your shims would need to be tool steel and ground flat............and even after doing all that in most cases it's doubtful that you would have enough clamping force to hold the shims & stands in place without them moving around after a period of time.

 

[jasonmark1993]

Shimming under the springs to get equal spring height wont change the valve stem height. Are you staying the tips of the valve stems are alot diff. from valve to valve?

You'll have to find out what the spec is for your set of heads and measure them. You can grind the tip down, but if you can see that they are way off, might be something else going on. Unless they have different length valves in there, the seat and how much the valve have been ground will be what changes the stem height.