Valve Stem Height Spec's?

[OUR87GN]

Anyone know where I can find the valve stem height spec's. I need to verify that I am within tollerance after a valve grind. (Stock cam and Lifters)
Thanks
Mark

 

[QuickWrench]

Unless they ground the #ell out of the seats and the deck, you're most likely fine, as long as the seats seal properly. The most important thing to double check is the springs' installed pressure, since they're at a greater installed height.

This was all I had on hand. Assuming you're running the stock cam...

Valve Spring
Valve Closed 90 lbs +or- 4 @ 1.727 in
Valve Open 245 lbs +or- 10 @ 1.340 in

Intake Valve
Head Diameter 1.715 in. - 1.705 in
Seat Angle 45 degrees
Stem Diameter .3412 in. - .3401 in
Clearance in Guide .0015 in. - .0035 in

Exhaust Valve
Head Diameter 1.505 in. - 1.495 in
Seat Angle 45 degrees
Stem Diameter .3412 in. - .3405 in
Clearance in Guide .0015 in. - .0032 in

I don't know that there's a spec for the installed valve tip height above the spring seat or the guide, but I could be wrong. If the shop was smart, they ground the seats to equal depths, in which case you're good to go.

I don't have the Power Source book with me, but there's more info in there. If you still need it after tonight, email me at Quickwrench@Runbox.com .

 

[OUR87GN]

Valve Stem Height Spec's

I checked my Power Source book tonight and didn't find any information on stem height. My concern is this - by grinding the valve seats you essentially move the valve stem height higher thus loading the valve lifters deeper. Then when you surface the heads you would lower the valve height in comparision to the valve lifters. I would think with non- adjustable valve train there would be some specifications so that all the valve lifters would be loaded to a pre set amount. Or is this something I don't need to be concerned with?
Mark

 

[QuickWrench]

The real question is...how deep do the lifters need to be preloaded?

I'm not sure what the spec is, but you can definitely stand an additional ~.010" of preload, assuming you're using the stock camshaft, and valve springs with the appropriate spec...and that you're not revving it to 6,500 RPM.

Have you had the heads and/or block decked? If so, how much? A typical decking only removes ~.005", and a valve job doesn't remove much more, either. I've done several TR engines with a ~.005" deck mill on the heads and/or block, along with a simple valve job at the stock 45 degrees. These all used stock cams and Comp 979 or 980 springs, and none of them required new pushrods. They've all successfully run 11 second ET's, or very close.

Hope that helps.