Not able to reach zero lash extensions even with lifters pumped up

[joshua]

1987 roller 302 I bought. Didn’t have push rods. I ordered comp 7826-16 rods. Which is 6.248 inches (6.25)

I have the rockers tightened all the way and there’s still slack. Against my better judgment I pumped up the lifters by priming the engine, hoping that would take care of it.

What am I missing here?? Could they be the wrong rocker arms?? In case it gets asked there’s roller lifters in there.

 

[joshua]

So I put the adjustable rod in there to zero lash, and the lengths look exactly the same, I’m sure they aren’t the same. But I can’t tell. And my calipers only go to 6 inch

 

[Broncobowsher]

Look at the lifter that is on a base circle. Is the plunger compressed enough that it is not touching the circlip?
With the pushrods the right length, the little wiggle I saw you do is normal. It is NOT rock solid.
When I had to do custom pushrod lengths, I figured the travel of the lifter plunger (this was 20+ years ago, I forgot how I did that). Then I set the pushrod to plunge about half that travel. It worked for me. With positive stop rocker arms (non-adjustable, just tighten until you reach the torque value) you need pushrods that are correct for something in the range of the lifter travel. Not bottomed, not topped, that is correct.

 

[joshua]

So basically they are not adjustable? I just put the rocker arm bolts all the down? I’ve only ever adjusted roller rockers with Polly locks. And this amount of play is fine in this close up video?

 

[joshua]

Ok, I got it. Man I feel dense rn. Ok
thanks!

But this just seems so wrong compared to what I’m used 2

 

[DirtDonk]

So basically they are not adjustable? I just put the rocker arm bolts all the down?

Yes, non-adjustable rockers. There is a procedure and a torque spec for engines that use this type of valvetrain.
In a perfect world, you don't even need to check. You just run the bolts down, torque them to whatever the spec is, and done.
It's usually not much either. Something in the range of 25lbs or so.
But that's where the book comes in handy.

In an imperfect world (real world!), or as in your case, where you have to purchase new pushrods, checking is still in order.
So you run the bolt down to zero lash (no up and down movement) and then count the turns to fully tight. There is a specification based on thread pitch, that dictates how many turns, or fractions of a turn, it takes to put the piston of the lifter in it's correct range.

But this just seems so wrong compared to what I’m used 2

By the looks of it, that is indeed wrong!
The first video, of the rocker arm moving side to side and such, is just like you would see with an adjustable rocker arm. They are NEVER so tight that you can't even move them.
The only time they get close to that tight, is when the valve is lifted way off the seat and the cam lobe is pushing things tight.
Remember, "zero lash" has nothing to do with spinning the pushrod or having a rocker arm that does not wobble or rock.
It has everything to do with the pushrod not being able to move up and down. Or the rocker to rock against a gap left by the pushrod.
Zero lash, is zero gap. But not zero movement.

However, all that said, that second video looks like things are wayyyyy off! Even on the base circle, you should never see the pushrod moving up and down out of it's seat/pocket of the pushrod or rocker arm.
Something is still amiss here...

Further videos might come in handy if you don't mind.

Paul

 

[joshua]

Yes, non-adjustable rockers. There is a procedure and a torque spec for engines that use this type of valvetrain.
In a perfect world, you don't even need to check. You just run the bolts down, torque them to whatever the spec is, and done.
It's usually not much either. Something in the range of 25lbs or so.
But that's where the book comes in handy.

In an imperfect world (real world!), or as in your case, where you have to purchase new pushrods, checking is still in order.
So you run the bolt down to zero lash (no up and down movement) and then count the turns to fully tight. There is a specification based on thread pitch, that dictates how many turns, or fractions of a turn, it takes to put the piston of the lifter in it's correct range.


By the looks of it, that is indeed wrong!
The first video, of the rocker arm moving side to side and such, is just like you would see with an adjustable rocker arm. They are NEVER so tight that you can't even move them.
The only time they get close to that tight, is when the valve is lifted way off the seat and the cam lobe is pushing things tight.
Remember, "zero lash" has nothing to do with spinning the pushrod or having a rocker arm that does not wobble or rock.
It has everything to do with the pushrod not being able to move up and down. Or the rocker to rock against a gap left by the pushrod.
Zero lash, is zero gap. But not zero movement.

However, all that said, that second video looks like things are wayyyyy off! Even on the base circle, you should never see the pushrod moving up and down out of it's seat/pocket of the pushrod or rocker arm.
Something is still amiss here...

Further videos might come in handy if you don't mind.

Paul

What would you like to see?

Could this be a lifter issue?
Because it seems like half the pushrods are ok and half aren’t. when spinning the oil pump with a drill and cycling the engine by hand, about half (pushrods) seem to keep contact when the lifter is at the bottom of the bore. Maybe the cups are shot on top of lifters? Because they are definitely pumped up.

He did give me a set of lifters that were supposed to be low miles. They looked like they had little wear. But maybe it’s them?

Only other thing I can think of is the the camshaft. Or I did swap head gaskets as I was going to put different heads on here

 

[joshua]

I swapped 2 working lifter locations with 2 sloppy locations. Swaping just the lifters. It didn’t make a difference per location even tho the lifters were changed. Which tells me it’s not the lifters.

Also all the lifters have to be at the very tip top to create zero lash. And on most of them I believe it’s barely zero lash as I can still easily spin most of them. These are 6.25 pushrods. I think I need to order 6.3s as I believe this is the next size up.

 

[73azbronco]

1987 roller 302 I bought. Didn’t have push rods. I ordered comp 7826-16 rods. Which is 6.248 inches (6.25)

I have the rockers tightened all the way and there’s still slack. Against my better judgment I pumped up the lifters by priming the engine, hoping that would take care of it.

What am I missing here?? Could they be the wrong rocker arms?? In case it gets asked there’s roller lifters in the

I think we are making easy hard here. Yes the following is AI, but also the same from my ford manual for stamped rockers and hydraulic lifters.

You started saying "roller 302". I am not seeing roller rockers. I see oem stamped steel sliding tip rockers and then you also show hydraulic lifters.

Here is how to install the rockers:

Installing factory "sliding" (stamped steel, non-roller) rocker arms on a 1987 Ford 302 (5.0L) with hydraulic lifters uses a pedestal-mount design. These are mechanically non-adjustable assemblies; the lifter preload is determined automatically when you torque the mounting bolts down onto the cylinder head pedestal.

This is how to check:

You must install and check the rocker arms one cylinder at a time when that specific cylinder is at Top Dead Center (TDC) on its compression stroke. At this position, both the intake and exhaust lifters sit on the "base circle" (lowest point) of the camshaft, ensuring the valves are completely closed. [1, 2, 3]

Step 1: Find TDC for the Target Cylinder

1. • Rotate the crankshaft by hand (using a socket on the harmonic balancer bolt) in the engine's normal rotation direction. [1, 2]
   • Watch the pushrods for the cylinder you are working on. Rotate until the exhaust valve opens and completely closes, and the intake valve does the same.
   • Bring the cylinder's piston to the top. (For Cylinder #1, align the timing pointer with 0 or TDC on the harmonic balancer). Both lifters should be at their lowest point. [1, 2]

Step 2: Lay Down the Components

1. • Place the pushrods down into their lifter cups, ensuring they seat perfectly.
   • Apply assembly lube generously to the pushrod tips and the top pad of the valve stems where the rocker arm slides.
   • Fit the aluminum/steel channel ("bridge" or "pedestal guide") onto the cylinder head slot.
   • Coat the curved bottom of the rocker arm fulcrums with assembly lube and lay the stamped steel rocker arms over the pedestal.
   • Dip the 5/16" mounting bolts in clean engine oil, drop them through the fulcrums, and engage the threads by hand. [1, 2, 3, 4]

Step 3: Find "Zero Lash"

1. • Tighten the pedestal bolt by hand using only your fingers (no socket wrench yet) while simultaneously spinning or gently jiggling the pushrod up and down. [1, 2]
   • Stop tightening the bolt the exact moment you eliminate all vertical slack/play in the pushrod. This point is Zero Lash. The pushrod should still spin with slight resistance, but it cannot move up or down. [1, 2, 3, 4]

Step 4: Torque and Count the Turns (The Preload Test)
This is the most critical safety checkpoint for a Ford pedestal setup. [1]

1. • Place your torque wrench on the bolt.
   • Slowly tighten the bolt down to its final factory specification of 18–25 ft-lbs.
   • Carefully count how many turns the wrench rotates from the exact point of Zero Lash until the torque wrench clicks. [1, 2, 3]

Reading Your Results (Troubleshooting)
Because Ford factory pedestals dictate the physical height of the valvetrain, your turn count translates directly to your lifter preload. [1]

• • The Sweet Spot (1/4 to 1 Full Turn): If it takes between 1/4 and 1 full turn (ideally 1/2 to 3/4 turn) to hit the 18–25 ft-lbs threshold, your valvetrain geometry is perfect. You can leave it and move on to the next cylinder. [1, 2, 3, 4]
  • Too Many Turns (More than 1 Turn): This means your pushrod is effectively "too long," which over-compresses the hydraulic lifter plunger. The valves may hang open, causing low compression or backfiring.
    • The Fix: You must place a specialized pedestal shim under the rocker channel. Shims typically come in 0.030" or 0.060" sizes (a 0.030" shim reduces the rotation by roughly 1/4 turn). [1, 2, 3]
  • Too Few Turns (Less than 1/4 Turn): This means the pushrod is "too short". The valvetrain will have excessive slack when running, resulting in a loud metallic ticking or clattering sound.
    • The Fix: You cannot fix this with shims; you will need to purchase slightly longer custom-length pushrods. [1, 2, 3, 4]

Repeat this exact cylinder-by-cylinder process following the standard firing order until all 16 rockers are securely torqued. [1, 2]

 

[joshua]

Roller as in roller cam. And stock stamped rockers. The engine was what I was referring to as a roller. Sorry for the confusion.

I have the pedestals cranked all the way down and torqued to spec. I just can’t imagine that in any part of the lifter cycle that it can be ok for the pushrods to be able to break contact with the lifter. There must also be some tension always. And as stated they are pumped and to the top.

Also on the one side it’s almost every single one but one that’s out of whack. But on the other side it’s just the one that isn't happy. And the rest that I’m calling happy are barely happy. There is something definitely wrong.

I believe it is the aftermarket cam. I’m thinking that it is I tiny bit skinnier. Idk what else would call for longer pushrods on an otherwise stock 302. I think I’m going to attempt to make a solid lifter out of one of these stock ones and use the adjustable pushrod to try and prove my theory.

I ordered a cheap 8 inch caliper of Amazon. I usually don’t cheap out on precision measuring devices, but I’m only going to use this very rarely and I have a known length pushrod to check if it’s measuring correctly.

 

[DirtDonk]

I swapped 2 working lifter locations with 2 sloppy locations. Swaping just the lifters. It didn’t make a difference per location even tho the lifters were changed. Which tells me it’s not the lifters.

Good test. Glad you went to the extra trouble to confirm this.
Agree that it's not the lifters. At least not them being defective. But it could still be that they're too short.
They look pretty "normal" from here, but while you're in this deep, you might just take a length measurement and compare it to some specification somewhere.

Also all the lifters have to be at the very tip top to create zero lash.

So that's another confirmation that something is too short. Have you triple checked the expected pushrod length against known data?
I'm no good at remembering pushrod lengths, so no help there.

And on most of them I believe it’s barely zero lash as I can still easily spin most of them.

Lets make this clear. Even though I think you have the difference in your head, your words are not clear. To be clear, YOU CAN STILL SPIN A PUSHROD AT ZERO LASH.
Sometimes VERY easily. In fact, there are some engines, especially with well broken-in components, that you can still spin the pushrods by hand even when the valve is fully open!
So stick with the "up and down" aspect, and ignore the spinning as a guide. Just use spinning by hand as a point of reference for yourself. But it has nothing to do with being at zero lash.

These are 6.25 pushrods. I think I need to order 6.3s as I believe this is the next size up.

Stop! Don't just order the next size up. You said you have a pushrod-checker, so use it to get an exact measurement.
Or I should say, use it again. I know your last results were not that far off, but something is wrong with that test, so try again.
If you can't get to zero lash at all, and can lift the pushrod up and down in the lifter even with the rocker fully torqued, I'm reasonably certain that adding merely .05" is going to make any difference.
Save your money until we've got this thing narrowed down a bit more.

I have the pedestals cranked all the way down and torqued to spec. I just can’t imagine that in any part of the lifter cycle that it can be ok for the pushrods to be able to break contact with the lifter. There must also be some tension always.

You are 100% correct.

Also on the one side it’s almost every single one but one that’s out of whack. But on the other side it’s just the one that isn't happy. And the rest that I’m calling happy are barely happy. There is something definitely wrong.

Let's see what the pushrod checker says again. And checking some of the known worst ones against some of the known "best" ones, see what the actual difference is.
Sorry you don't have a big caliper for this use. I bought one a couple of years ago and have not used it yet. Knew I'd need it someday.
Sorry I'm all the way over here, or you could borrow it.

In the meantime, you can get pretty darn close with a tape-measure with fine graduations.
Maybe even mark a piece of paper with lines, when you get the checker out, and then measure between them with the tape. Gotta be close at least.

I believe it is the aftermarket cam. I’m thinking that it is I tiny bit skinnier. Idk what else would call for longer pushrods on an otherwise stock 302. I think I’m going to attempt to make a solid lifter out of one of these stock ones and use the adjustable pushrod to try and prove my theory.

Excellent idear. Since there are cams with purposely built small base circle designs, you might be on to something.
You might as well peer down the bores too, whenever a lifter is out, to see if the lobes are still good. While not as common as wiped out flat-tappet lobes, roller cam lobes are not immune to the modern cam metallurgy debacles.

I ordered a cheap 8 inch caliper of Amazon. I usually don’t cheap out on precision measuring devices, but I’m only going to use this very rarely and I have a known length pushrod to check if it’s measuring correctly.

Bingo. Doesn't have to be the best quality. Heck, you can even compare it to a tape measure! Just to make sure that it's only .001" off, rather than .010" off.
Just like the tape measure method, a cheap caliper should get you there.

Good luck.

Paul

 

[joshua]

Good test. Glad you went to the extra trouble to confirm this.
Agree that it's not the lifters. At least not them being defective. But it could still be that they're too short.
They look pretty "normal" from here, but while you're in this deep, you might just take a length measurement and compare it to some specification somewhere.

So that's another confirmation that something is too short. Have you triple checked the expected pushrod length against known data?
I'm no good at remembering pushrod lengths, so no help there.

Lets make this clear. Even though I think you have the difference in your head, your words are not clear. To be clear, YOU CAN STILL SPIN A PUSHROD AT ZERO LASH.
Sometimes VERY easily. In fact, there are some engines, especially with well broken-in components, that you can still spin the pushrods by hand even when the valve is fully open!
So stick with the "up and down" aspect, and ignore the spinning as a guide. Just use spinning by hand as a point of reference for yourself. But it has nothing to do with being at zero lash.

Stop! Don't just order the next size up. You said you have a pushrod-checker, so use it to get an exact measurement.
Or I should say, use it again. I know your last results were not that far off, but something is wrong with that test, so try again.
If you can't get to zero lash at all, and can lift the pushrod up and down in the lifter even with the rocker fully torqued, I'm reasonably certain that adding merely .05" is going to make any difference.
Save your money until we've got this thing narrowed down a bit more.

You are 100% correct.

Let's see what the pushrod checker says again. And checking some of the known worst ones against some of the known "best" ones, see what the actual difference is.
Sorry you don't have a big caliper for this use. I bought one a couple of years ago and have not used it yet. Knew I'd need it someday.
Sorry I'm all the way over here, or you could borrow it.

In the meantime, you can get pretty darn close with a tape-measure with fine graduations.
Maybe even mark a piece of paper with lines, when you get the checker out, and then measure between them with the tape. Gotta be close at least.

Excellent idear. Since there are cams with purposely built small base circle designs, you might be on to something.
You might as well peer down the bores too, whenever a lifter is out, to see if the lobes are still good. While not as common as wiped out flat-tappet lobes, roller cam lobes are not immune to the modern cam metallurgy debacles.

Bingo. Doesn't have to be the best quality. Heck, you can even compare it to a tape measure! Just to make sure that it's only .001" off, rather than .010" off.
Just like the tape measure method, a cheap caliper should get you there.

Good luck.

Paul

Hey Paul the cam is brand new. And has never been ran. I had pulled it out to inspect earlier. But I have no idea how it was cut, as I didn’t buy it, or originally install it. I did decide to take the measurements with the rod checker because I’m not going to be able to order pushrods until Monday anyway.

Any one have any idea where to get just regular non hardened pushrods at custom lengths? This motor is supposed to be a quick stop gap to a 408 build m planning. So I really don’t want to spend 150 to 300 on push rods

 

[73azbronco]

Just to confirm, you set each torque on the base of the cam with both valves closed for each cylinder

 

[joshua]

Just to confirm, you set each torque on the base of the cam with both valves closed for each cylinder

Yes, when the lifter was at its lowest point, then went back and checked it again when both valves were closed. I know, I’m really weirded out by it. I’m hoping it wasn’t decked goofy.

 

[joshua]

@DirtDonk

Zero lash on rod checker is 6.2745 (which is extremely close to the 6.720 ford says the original one would have been) and the stock length comp cam ones measurement is 6.2575

So I think I’m supposed to add 30 Thousandths on to 6.2745 which gives me 6.3054

I’m thinking that’s the 6.3 rods? I think the next size after is 6.4 which is way longer.

Lmk what you guys think pls

First pic I the rod checker and 2 is what comp says is the stock length.

 

[joshua]

Maybe these?

These would still be the ball type right? They just don’t have the backside of the ball machined in them. As I can’t find any custom ones that are like the original ball exactly.

https://www.jegs.com/b/746-PCE254.1...LkENhk0Q3VF_S4LcQlq890mTmUtE-PqUaAqPvEALw_wcB

 

[Broncobowsher]

FYI, you can run hardened pushrods. Won't hurt anything. No guide plates can run either hardened or non hardened. With guide plates, need hardened.
Hardening is an extra process, adds cost in mass production. Aftermarket it makes a single part more versatile as it can be used either way.

Like getting a replacment radiator. They (generally) all come with transmission coolers built in. That way a single part number, a single item in inventory, will fit both automatics and manuals. It is extra cost to make, but less cost than inventory and added part numbers.

 

[nvrstuk]

Wishing ya the best here. Anybody having problems clicking on and enlarging his pics & videos???
I can't open or enlarge any of the OP pics as McAfee says it is "downloading" them? Never had this happen once b4 here or anywhere. Just me and my "new-ish" laptop... lol

 

[joshua]

FYI, you can run hardened pushrods. Won't hurt anything. No guide plates can run either hardened or non hardened. With guide plates, need hardened.
Hardening is an extra process, adds cost in mass production. Aftermarket it makes a single part more versatile as it can be used either way.

Like getting a replacment radiator. They (generally) all come with transmission coolers built in. That way a single part number, a single item in inventory, will fit both automatics and manuals. It is extra cost to make, but less cost than inventory and added part numbers.

Yes, just trying to spend less. I also read they break stuff instead of being the fuse that bends. But I highly doubt I’ll be holding at 7k rpm anytime soon, so the hardened ones are fine. The ones I mentioned in the post above are very reasonable and hardened. I’m just wondering if they will work. Idk why they wouldn’t, but if they do work idk understand why they made the extra work for themselves originally making it into mostly a ball shape versus the dome on these.

 

[joshua]

Wishing ya the best here. Anybody having problems clicking on and enlarging his pics & videos???
I can't open or enlarge any of the OP pics as McAfee says it is "downloading" them? Never had this happen once b4 here or anywhere. Just me and my "new-ish" laptop... lolV

Video is 3 seconds. Sorry I don’t have a you tube channel, and if you keep the video under I believe 10 seconds you’re able to just attach it instead of having to use you tube. Might try looking at it from your phone if you’re really dying to see it lol.

Basically it’s a rocker arm screwed all the way down. A lifter as low in its bore as possible, and the push is able to dance around the cup that it sits in on the lifter.