440 roller rocker adjustment problem

[charger01]

Iam running a 292 comp cam and hydraulic lifters.  crane cam gold rockers with matching pushrods.  Initially the setup adjusted and worked fine upon initial engine breakin.  The motor ran for about a half hour and then for some reason the cam bolt washer broke in 4 places.  I replaced 2 bent valves and replaced the pushrods.  For some reason now, I can not adjust the rockers(valves).  The pushrods end up binding on the rocker arm even with the rocker adjuster totally out.  Even the original pushrods no longer work.  Everything is still the same.  What could I be doing wrong here.  Iam clueless.

[firefighter3931]

Some questions ;

Have the lifters collapsed ? Are the adjusters damaged ? Pushrod cups damaged ?

If the pushrods are the proper length you should only have 1-2 threads showing on the adjuster after the preload has been set.

Post a pic so we can see what's going on.


Ron

[charger01]

The pushrods are all new, adjusters are all fine and to the best of my knowledge the lifters are all fine.  I cant even bolt the rocker assembly all the way down.  There is always at least one pushrod that is binding on the bottom of the rocker arm.  The same setup worked fine before the cam washer gave way.  Not sure what could change.  Like I said I had the heads redone to look for any bent valves.  This may be a dumb question, but could the shop have anything to do with them not fitting now?

[firefighter3931]

Ch01, i doubt if the shop could have done anything to create this issue. Are you sure that the pushrods are the correct length ? Have you compared them to one of the old pushrods ?

Ron

[charger01]

Yeah, they are the same length.  The ball tip on the new ones are a little bigger but not much.  Nonetheless even the original ones bind up now.  I don't know what is going on.

[firefighter3931]

Post some pics so we can see what's going on...

Ron

[Steve P.]

Are you having this problem with the same 2 pushrods as the 2 valves that you had replaced??

Which 2 valves were replaced?

Have you checked the lifters and lifter bores?

Did you check both heads?

While the head or heads were off did you turn the motor by hand??

Are you sure you have the pushrods set IN the lifter cups??



I'm not trying to sound like a smart ass, just need more/better info to help..

[charger01]

[charger01]

[charger01]

[charger01]

I wasnt sure what pics to post but these show where the pushrod hits the rocker arm.  Another pic shows the same pushrod where it sits into the compressed lifter.  All the pushrods will hit the rocker arm when the cam hits that perticular pushrods maximum lift.  Even the original ones that worked fine initially for a half hour before the cam failure bind up now. There were two valves replaced,  I believe they were #5 intake and exhaust.  I checked the lifters and bores visually.  Didnt see anythiing wrong.  Anythng to look for in perticular?  Both heads were checked out by a local machine shop and they replaced the two slightly bent valves.  I did turn the motor over numerous time while the heads were off.  I sanded down the spots on top of the pistons where the valves had hit.  The pushrods are sitting in the lifters as they should .  I cannot fiure out while even the old pushrods will not work.  This car is driving me nuts.  Its always something.  Please help?

[firefighter3931]

Things look fairly normal in that pic. The one thing that i can see is that the adjuster is in too far into the rocker arm. The proper preload should have the adjuster showing 1-2 threads below the rocker arm.....in your pics, the adjuster isn't showing any threads which is causing the pushrod cup to contact the bottom of the rocker arm. The adjusters need to be screwed tighter so that the ball end protrudes further below the rocker arm. Hope that makes sense....

Can you measure a pushrod ? I'd like to know the length from the bottom of the pushrod to the bottom of the cup (on the rocker arm end).


Ron

[charger01]

They are about 9 3/16  inches long.  crane cams p/n 270-64673 which is what they recommended to go with their rocker arms.  When I adjust the adjuster into the pushrod it is way to tight.  if I try to turn the motor over you can hear the stress on the pushrods.

[Steve P.]

With the rocker assy. off the head, put a straight edge across the tops of the valve tips.  I am wondering if the machine shop ground the snot out of the seats!! They should be pretty even.

They are about 9 3/16  inches long.  crane cams p/n 270-64673 which is what they recommended to go with their rocker arms.  When I adjust the adjuster into the pushrod it is way to tight.  if I try to turn the motor over you can hear the stress on the pushrods.

Did you replace just the 2 bent pushrods or all of them?

In this pick the rocker on the left is showing 1 thread, (HARD TO TELL), maybe 2. If you turn the motor over 180* the lifter should be on the base circle of the cam. At that point is the pushrod contacting the rocker at all?? It should NOT be. That is when you want to adjust the rocker. It should NOT open the valve adjusting the rocker to (1 or 2) threads showing under the rocker.

Let us know..

[firefighter3931]

They are about 9 3/16  inches long.  crane cams p/n 270-64673 which is what they recommended to go with their rocker arms.  When I adjust the adjuster into the pushrod it is way to tight.  if I try to turn the motor over you can hear the stress on the pushrods.

That is the correct part number for your setup. Those are supposed to be 9.125 in long so your measurement is close enough. The only other thing i can think of is that the lifters are pumped up solid and haven't bled down...we need to check that....

Remove all the pushrods except #1 exhaust and rotate the engine over until the lifter is on the base circle of the cam...lowest point in the lifter bore. Install the pushrod and tighten down the rockershaft. Take a look at the plunger in the lifter to see how far it is dropping down inside the lifter body....it shouldn't be much. Ideal preload is .020 with a couple threads of the adjuster showing. The plunger should drop slightly if the lifter is working properly...turn the adjuster screw until 1-2 threads are showing on the underside and report back.

Also check a lifter or two to see if you can compress them down. Make sure you mark the lifter's location because it must be returned to it's location or you risk wiping the cam.

Ron

[mopar1968]

I helped a neighbor of mine with his chevy small block.  It turns out his timing chain was off a couple teeth causing all the trouble.  I know when you get frustrated things start getting overlooked.

Just a thought.

[charger01]

With the rocker assy. off the head, put a straight edge across the tops of the valve tips.  I am wondering if the machine shop ground the snot out of the seats!! They should be pretty even.

They are about 9 3/16  inches long.  crane cams p/n 270-64673 which is what they recommended to go with their rocker arms.  When I adjust the adjuster into the pushrod it is way to tight.  if I try to turn the motor over you can hear the stress on the pushrods.

Did you replace just the 2 bent pushrods or all of them?

In this pick the rocker on the left is showing 1 thread, (HARD TO TELL), maybe 2. If you turn the motor over 180* the lifter should be on the base circle of the cam. At that point is the pushrod contacting the rocker at all?? It should NOT be. That is when you want to adjust the rocker. It should NOT open the valve adjusting the rocker to (1 or 2) threads showing under the rocker.

Let us know..

Yes, I replaced all the pushrods.  In the pics posted none of the rockers are really adjusted yet.  You can't really even put the rocker shaft on without one pushing up on the rocker to far.  If the timing chain was off by a tooth could that really cause this?  Thank you so much for all your help here guys.  I hope we can figure this out.

They shoudnt of ground the seats,  since the heads were actually already redone . They were just checking for bent valves.

[mopar1968]

With the rocker assy. off the head, put a straight edge across the tops of the valve tips.  I am wondering if the machine shop ground the snot out of the seats!! They should be pretty even.

They are about 9 3/16  inches long.  crane cams p/n 270-64673 which is what they recommended to go with their rocker arms.  When I adjust the adjuster into the pushrod it is way to tight.  if I try to turn the motor over you can hear the stress on the pushrods.

Did you replace just the 2 bent pushrods or all of them?

In this pick the rocker on the left is showing 1 thread, (HARD TO TELL), maybe 2. If you turn the motor over 180* the lifter should be on the base circle of the cam. At that point is the pushrod contacting the rocker at all?? It should NOT be. That is when you want to adjust the rocker. It should NOT open the valve adjusting the rocker to (1 or 2) threads showing under the rocker.

Let us know..

Yes, I replaced all the pushrods.  In the pics posted none of the rockers are really adjusted yet.  You can't really even put the rocker shaft on without one pushing up on the rocker to far.  If the timing chain was off by a tooth could that really cause this?

You would be surprised what can happen with the timing chain only a couple teeth off.  I'm not sure if you had to remove the cam sprocket when you replaced the washer, but if so it could be 180 off too....

With my neighbors 350, it bent 2 pushrods and was only off a couple teeth.  It didn't seam to hurt any valves though.  It must have been in the middle ground before valve damage. 

I only figured his problem out because I sent him to the store for more cigs and beer, while I took a good look at everything with fresh eyes.  You never know.  It could still be something with your rockers or lifters or whatever.  Since you have everything apart, just double check.

[charger01]

Is it possible the valves are installed too high?  Does this make sense?

[firefighter3931]

Is it possible the valves are installed too high?  Does this make sense?

It's unlikely that all the valves were improperly installed, inmo.

Like i suggested above, try mocking up just one pushrod ; #1 exhaust would be fine. Rotate the engine over until the lifter is on the heel of the cam....that is where it will be lowest in the lifter bore. Install the pushrod and rocker arm assembly...screw the adjuster down, so that 2 threads are showing on the bottom side of the rocker.

Look to see how far the lifter plunger is compressing. The lifter plunger should be moving slightly at this point....this is called lifter preload. Try pushing down on the top of the rocker arm (over top of the pushrod) and see how much further it compresses.

Basicly, what you're trying to do here is to make sure that the lifter plunger hasn't bottomed out in the lifter body. If it has, then the pushrods are too long, plain and simple.


Ron