Shimming old lifter to simulate preload for valvetrain setup

-
prorac1

prorac1

Well-Known Member
Joined
Sep 29, 2012
Messages
1,510
Reaction score
1,340
Location
Martin, Mi
I'm looking for ideas on how to set up a factory style hydraulic flat tappet lifter for .040-.060 plunger depth.

I need to verify pushrod length, and I need to check "actual valve lift" for coil bind.

I've disassembled hydraulic lifters before, flipped the piston, and made them solids. But I've never set plunger depth in a mock up lifter.

Any tricks? Thanks. Eric
 
I never did a mopar but I was checking a chevy sb piston to valve clearance so I took out the guts and cut a aluminum rod to take up the difference put the top back in and put the clip back in and it was solid.
 
Make a checking pushrod. With the camshaft on the base circles of of the one checking cylinder, adjust the pushrod so it pushes the plunger about .030 or so in. Then loosen the rocker shaft and measure the pushrod. Repeat for the other valve. Then move to the next pair. Rinse, repeat, writing down results. If they are all pretty close, pick a length and go. If not, you may need some custom length pushrods. The stock ones will probably work just fine.
 
To make a checking lifter:

Measure effective length of the lifter. This is from the lifter face to the cup where the pushrod sits. To do this you need a slide caliper and a ball bearing. The ball bearing must be as close to the diameter of the pushrod you’ll be using. Measure the diameter of the bearing and place the bearing into the lifters cup. Measure from the lifters face where the cam rides to the top of the ball bearing. Subtract the ball bearing diameter. Subtract the optimal lifter preload amount. Now you have the effective lifter length, including preload.

Obtain, make, or rent a “checking lifter”, to do this you must disassemble the lifters guts and and keep the cup part. Find a nut and bolt that will fit inside the bore of the lifter nicely, preferably fine thread. Drop the nut inside the bore. Thread in the bolt. Put the cup on top. Turning the bolt will allow you to change the effective length so the cup moves inward/outward. Cut the bolt If it’s too long. Epoxy the cup to the bolt and use your fingertip to make adjustments, only if this is a spare lifter.

Use your measurements and use the ball bearing again to make the checking lifter the exact size as your original lifters. Now you have a solid lifter that is the exact effective length and includes lifter preload. Score or mark a line on the cup and lifter to make it easier to see if the cup has shifted position and changed the length.

Now you can check piston to valve clearances, measure for pushrods, and check the sweep of the rocker over the valve tip.

When adjusting the pushrod, always keep the lifter end stationary, you’ll be adjusting the rocker side. This will keep the checking lifters guts from adjusting as the pushrod expands and puts pressure on the checking lifter.
 
I'm glad someone understood the persons first post. His question was very specific & on point. Thank you T56MaxTorq
 
72Dart6pack said:
I'm glad someone understood the persons first post. His question was very specific & on point. Thank you T56MaxTorq
Click to expand...
And some of us understand what is necessary and what isn't.
Finding actual valve lift will determine how much coil bind cushion you have. Installed height is x, deduct actual lift at valve from x and you have y amount till coil bind at 1.100
1.57-.420=1.150 for instance.
Then check between coils with feeler gauge, .050 between each central spring coil is the min you need...and if you ever read any circle track mags.... the biggest name say to run the springs that way, the rest you can search up sometime.
Im running k motion 800's within .050 coil on my own stuff.
 
T56MaxTorq said:
To make a checking lifter:

Measure effective length of the lifter. This is from the lifter face to the cup where the pushrod sits. To do this you need a slide caliper and a ball bearing. The ball bearing must be as close to the diameter of the pushrod you’ll be using. Measure the diameter of the bearing and place the bearing into the lifters cup. Measure from the lifters face where the cam rides to the top of the ball bearing. Subtract the ball bearing diameter. Subtract the optimal lifter preload amount. Now you have the effective lifter length, including preload.

Obtain, make, or rent a “checking lifter”, to do this you must disassemble the lifters guts and and keep the cup part. Find a nut and bolt that will fit inside the bore of the lifter nicely, preferably fine thread. Drop the nut inside the bore. Thread in the bolt. Put the cup on top. Turning the bolt will allow you to change the effective length so the cup moves inward/outward. Cut the bolt If it’s too long. Epoxy the cup to the bolt and use your fingertip to make adjustments, only if this is a spare lifter.

Use your measurements and use the ball bearing again to make the checking lifter the exact size as your original lifters. Now you have a solid lifter that is the exact effective length and includes lifter preload. Score or mark a line on the cup and lifter to make it easier to see if the cup has shifted position and changed the length.

Now you can check piston to valve clearances, measure for pushrods, and check the sweep of the rocker over the valve tip.

When adjusting the pushrod, always keep the lifter end stationary, you’ll be adjusting the rocker side. This will keep the checking lifters guts from adjusting as the pushrod expands and puts pressure on the checking lifter.
Click to expand...

This was exactly what I was looking for!

The only part I'm a little foggy on is the ball bearing? Is it used to take up the gap between the cup and the top of the lifter?

Much better than my, "pile washers in place of the lifter piston idea. Lol

Thank you again. Eric L
 
Id rather pile washers, at least i have those in the bin.
As long as it ends up correct, whatever floats your boat.
I stopped reading half way through, shouldn't take that many words to explain such a simple task. Geezus
 
MOPAROFFICIAL said:
And some of us understand what is necessary and what isn't.
Finding actual valve lift will determine how much coil bind cushion you have. Installed height is x, deduct actual lift at valve from x and you have y amount till coil bind at 1.100
1.57-.420=1.150 for instance.
Then check between coils with feeler gauge, .050 between each central spring coil is the min you need...and if you ever read any circle track mags.... the biggest name say to run the springs that way, the rest you can search up sometime.
Im running k motion 800's within .050 coil on my own stuff.
Click to expand...

This is exactly why I need to do this. But lifter preload must be taken into account. My results will not be accurate if I don't shim the test lifter at preload height.

Won't I just be fully depressing the piston to the bottom of its stroke if I don't shim it?

And if I make it solid at the top of its stroke, than the solid pushrod I'm using to check lift will hold the valve open?

Thank you to everyone for your advice and help.

It takes a village to build an engine. Lol.

Thanks again. Eric
 
prorac1 said:
This is exactly why I need to do this. But lifter preload must be taken into account. My results will not be accurate if I don't shim the test lifter at preload height.

Won't I just be fully depressing the piston to the bottom of its stroke if I don't shim it?

And if I make it solid at the top of its stroke, than the solid pushrod I'm using to check lift will hold the valve open?

Thank you to everyone for your advice and help.

It takes a village to build an engine. Lol.

Thanks again. Eric
Click to expand...
But the .040 is taken by the lifter, not the valve.
Yes, pull the lifter apart and shim it, either all the way and figure .040 in later for length or shim .040 from max cup rise and extend the checking push rod to zero lash while on the base circle of cam and do it that way.
You get your push rod length when you add .040.... but in the meantime, you'll have the same lift with the lifter cup at full rise and no .040 figured in yet to the push rod zero lashed....again, because the lifter eats the .040 preload!
 
Last edited:
MOPAROFFICIAL said:
But the .040 is taken by the lifter, not the valve.
You get your push rod length when you add .040....
Click to expand...

Yes. That will work for checking pushrod length and preload.

But what about checking valve lift?

That's what I need this for.

Thanks. Eric
 
We are talking about a 318 with a small .460 cam, stock heads....whos saying the stock push rod aren't fine to use. This is definitely tinkering.
 
MOPAROFFICIAL said:
But the .040 is taken by the lifter, not the valve.
Yes, pull the lifter apart and shim it, either all the way and figure .040 in later for length or shim .040 from max cup rise and extend the checking push rod to zero lash while on the base circle of cam and do it that way.
You get your push rod length when you add .040.... but in the meantime, you'll have the same lift with the lifter cup at full rise and no .040 figured in yet to the push rod zero lashed....again, because the lifter eats the .040 preload!
Click to expand...

I was under the impression that when you tighten down the rocker shafts, you don't adjust "lash". The shaft just gets tightened down.

What happens to the .040 that wasn't accounted for in the solid lifter?

Sorry if I'm confusing things. It's my "schtick". Lol

Thank you again for the help
 
prorac1 said:
Yes. That will work for checking pushrod length and preload.

But what about checking valve lift?

That's what I need this for.

Thanks. Eric
Click to expand...
You don't understand what I'm saying at all.
Let's clarify something first. The checking push rod you have been told to use....is adjustable, it extends and retracts....so bolt the shaft down and adjust it at the checking push rod, hence adjustable. Make one out if an old one you have, cut it in half, all thread and 2 nuts between both ends and there ya go.
Use the push rod at .040 short the pre load on a shimmed to max cup rise hyd lifter. Check your max lift at valve now...
Once you find it's good, coil bind is .050 or more away, measure the length and add .040. That's the length you need.
When it goes together....the lifter shims removed... the .040 will be taken up by the lifter...hence preload that you are after.
That's it. Read it as many times as it takes or ignore it.
 
I was apprehensive to use the length checker with full spring pressure on it.

I have a storebought length checker.

But I had always been told not to use it under full spring pressure, because you can bend it.
 
prorac1 said:
I was apprehensive to use the length checker with full spring pressure on it.
Click to expand...
Use a check spring, I wouldn't have even sprung the head till I had everything checked 1st.
So here's what you do in your case, you get the pre load checked.....then after the length is determined.....weld up a mock up push rod that length and use it to check max lift and coil bind. That way it doesn't break or bend on you. I have a small pile of them from over the years, even some 273 push rod I shortened and welded up for use way back when. You do what you gotta do in this biz and get creative
 
Nothing is assembled as of yet.

But I do need to find a checking spring or weld the pushrod.

I think we're all on the same page now. Lol

Thanks again.

Boy, did I make that harder than it needed to be. Lol.

Next time just tell me to buy a checker spring. Lol
 
So, since my stuff isn't assembled, what can I use for a checker spring?
 
I guess my question is this.

Can I use a stock valve spring as a checker spring with the Comp cams adjustable pushrod and not do any damage
 
That's all we're checking pushrod length for. Just for the sake of checking.

Because I don't want to not check it and find out to late, 3,000 miles down the road, that we have been running .010 from the top or bottom of the travel after its to late.

I'm pretty sure the stock pushrod will work for what we're doing. But since I have the tools to check it. I'm checking it.


MOPAROFFICIAL said:
Once you get the length figured, measure a stock push rod , just for fun...
Click to expand...
 
You must log in or register to reply here.
-

Back
Top