Mopar Muscle Association UK

Okay so possibly the cam IS the culprit??? Damn, I could have examined the lobe before I put it back together... Hang on, I did see it partially when I first removed the lifter...I'm sure it was fine...

How about this - I fired it up with the push rod back in (but still well loose) but due to time limitations I could only run it for a couple of min's......guess what.....it didn't pump up I'm going to investiagte more tommorrow to see if it has jumped out again.

See, when I think back to to the first time I heard this rattle, it was noisy but it still ran on all 8 - like the lifter wasn't pumping up for some reason. Then, at some point during diagnosis/driving it the push rod must have popped out....but it can't/shouldn't, right?

So possibly I've got a lifter that wont pump up and a push rod that's too short?

Could the valve be stuck open a bit maybe It certainly doesn't look ike it is!

Possibly a weak spring.........

okay but that doesn't explain why I was able to pop the push rod back just by hand.....even when the lifter is not pumped up I wouldn't have thought that would be possible??

Adam maybe right. Someone had installed that 509 cam in my 440 and not fitted suitable valve springs for sure. They looked very similar to stock springs and were almost binding. Most cam manufacturers recommend you would need at least 60 thou more lift before the coils bind and I measured 16 thou.

Not being an expert,i would be checking the valve train,lifters & rods for excessive wear.
It should not be possible to put a push rod "back in",without something badly amiss,even with a bad lifter.
Seek & you shall find.

I take it the motor has stock rockers & not adjustable

yep. Stock

One thing I would check is the rocker its self as sometimes the pushrod can start to punch its way through. I have also seen a bent rocker but that was on a chevy.
It does sound as if there is an alignment issue here I would be taking off the rockers and checking that the valves are the same height ( maybe stuck down ), also pulling out a couple for the pushrods to check the length against each other and also pulling a couple of lifters and comparing them together (see if the height is the same from the base to the cup) whilst the lifter is out strip it down and clean it out.
If you have wiped out a lope on the cam you should be able to tell by looking at the base of the lifter.

just a note, A good friend of mine put some cheap lifters in a small block he used plenty of cam lube, he managed to wipe the lobes of the cam and wipe out the bottom half of his engine within 100 miles.

Something is amiss here pushrods don't just fall out. By the sounds of it the lifter has collasped, even if it won't pump up properly it's spring pressure would keep the pushrod in place, unless you have an odd pushrod that is too short. Check the pushrod length and strip the offending lifter before you go any further.

Hmmmm. What should the rod length be?? Obviously I can whip another one out if I remove the rocker shaft too and compare 'em...

B 8.555"
RB 9.295"

Taken from the 440 Source website, so I assume it's correct as I have no other info at hand....

eeekk whats B and RB?

B is low deck; 383, 400 (short stroke)
RB is high deck; 426, 440 (long stroke)
Therefore the b pushrods are shorter than the RB ones

Okay I reckon I know what's caused it - excessive play in the rocker. When I took it apart again just now I found that the push rod had basically popped straight out again hence why I thought the tappet wasn't pumping up.

On inspection (again limited by light!! arrrghh!) the lobe is fine as is the lifter and the valve is not open. So I turned my attention to the rocker and if I fit the rod in place but hold the rocker down so as to take up the slack (pushing down on to the valve/shaft) it doesn't come out.

The picture is useless really but thats me pushing up from underneath with my finger to highlight how much slack is there.....see that gap??? there's easily an eighth of an inch if not more. Surely thats too much

So, play in the rocker ....sound feasible?

Who sells rockers??!!! I want it sorted!!!