whtnuklz

iTrader: (8)

when checking PTV what length pushrods should you use with the solid test lifters and check springs. Do you use an adjustable pushrod set to zero lash? In my case with solid lifters at zero lash it is 7.350". In my completed engine I'll be running 7.425" which will give me .075 preload. If i'm checking PTV with 7.350" pushrods but actually using 7.425" pushrods in the completed engine wouldn't the PTV closer that what i checked it at with the 7.350"? It seems like if the engine is running at high rpm and the lifter is pumped up with the 7.425" pushrods, the ptv could get really close. I'm a little confused on this part could someone explain this?

JPH

iTrader: (2)

Length will not change your PTV. Use your stock 7.400 pushrods and set them to "0" lash and check your PTV. Length will determine pattern/preload.

whtnuklz

iTrader: (8)

so if the lifter was fully pumped up with a longer pushrod than used for checking it will not have any effect on ptv? its just something i was wondering about

BriancWS6

iTrader: (18)

I would use solid lifters to do this check. Take a couple old ones apart, remove the spring and stack the appropriate amount of washers in there and reassemble. Now, use your push rod length checker and adjust it out to zero lash with your rockers torqued down. You can now properly check P-V clearance.

vettenuts

iTrader: (4)

I assume you are checking with clay. Use the solid lifters and a pushrod that provides zero lash when the lifter is on the base circle. You can also double check with a dial indicator. One thing you won't measure is the system flex you will get when the motor is running, which will increase PTV.

When you install the longer length with preload, the lifter plunger will set so that PTV will be the same.

whtnuklz

iTrader: (8)

I've made two of my old lifters solid already. I used the clay method and was going to check with a dial indicator just to try the two different checks. I only asked this question because I was curious if the pushrod length difference would have any effect, and I see now the answer is no

vettenuts

iTrader: (4)

You will likely find the dial indicator gives a little less PTV then the clay.

whtnuklz

iTrader: (8)

the dial indicator is the more accurate of the two, right?

vettenuts

iTrader: (4)

It should be, but again it will be a little conservative because once you put in the real springs and the pushrod and rocker flex the PTV will actually increase on the running motor. Mine is a little under the accepted minumums on the intake side, but since the valve is chasing the piston I was less concerned then I would be if the exhaust were under since then you are depending on the valve spring to get the valve shut prior to the piston reaching the top.

01ssreda4

iTrader: (96)

If anyone wants to do this without using clay, I measured mine with peanut butter cookie. True story.