I am mocking up the valve train to measure for correct pushrod length and I need some clarification from the pro's. I have read up a lot of valve train geometry lately and pretty much given up on the idea of setting up for midlift (smallest wipe area). Given my hardware I just do not think I can make it work, so I am just going for the center wipe.
First, here is my hardware:
- SBC350, decked .020"
- L31 Vortec heads, milled (.010" ?), OEM pressed in studs
- Howard's Cams full roller rockers
- Comp Camps XE274H (230/236º @.050", .490")
- .026" Compressed thickness head gasket (although I am NOT using it in the mock up phase
When I tighten the polylock it is very clear when it bottoms out/zero lash is achieved. Is it from this point that I should go another 1/2 to full turn?
Where does the plunger on a hydraulic lifter normally operate at in a running engine (as in what height)? Doesn't it normally stay at the very top of the lifter, and when it is bumped by the cam it goes down a few thousands of an inch?
Right now I am getting a good centered roller wipe path with my adjustable pushrod set to 7.600". This "seems" short. When I tighten the polylock it is almost bottomed out on the stud shoulder. Is this normal/OK? Maybe I should consider lash caps? Are those OK to run in a street engine?
In this pic you see the where I am at with the 7.600" pushrod. The lightweight valve checking springs I got are pretty stiff. They are pushing the plunger on the hydraulic lifter down, so when I get to peak lift I use my hand to push the rocker down the rest of the way. I stop when the plunger reaches the top of the lifter. Is this OK?