440 valve failure

[Roman1970RR]

So I recently purchased a 1970 roadrunner and after only driving it half a dozen times and less than 300 miles I’ve blown a valve coming out of a roundabout at around 3000rpm.

Devastating is an understatement.

I am yet to pull the head off this weekend to see how much damage I am in for. I need some advice on what to replace and what combination of parts work best. I am in Australia and can’t seem to find any mopar engine experts here.

I am hoping piston isn’t damaged and can fix everything top end but at the very least I want to know best heads cam and intake manifold to use while it’s off-road I might as well beef the engine up and make it more reliable.

Look forward to reading any pointers. Thanks everyone.

 

[pnora]

I would look real close on those keepers and retainers. There could be a mis-match.

 

[dvw]

That doesn't look like a valve failure. It looks like the valve locks broke. Need a picture of the valve stem and a unbroken pair of locks (keepers). There are stamped locks or machined locks. With machined locks being a better option. At this point it's hard to tell if A; the locks plain failed, B; they were not installed correctly, C; the locks are the wrong style for the valve stem size and design. D; the lock angle and the retainer hole angle didn't match (7 degree with 8 or 10 degree).
Doug

 

[Roman1970RR]

That doesn't look like a valve failure. It looks like the valve locks broke. Need a picture of the valve stem and a unbroken pair of locks (keepers). There are stamped locks or machined locks. With machined locks being a better option. At this point it's hard to tell if A; the locks plain failed, B; they were not installed correctly, C; the locks are the wrong style for the valve stem size and design. D; the lock angle and the retainer hole angle didn't match (7 degree with 8 or 10 degree).
Doug

Thanks mate I will post more photos once the heads off.

 

[PRND21]

You dropped a valve at 3000 rpm. Unless the engine stopped instantly, you’re not going to like what you see when you take that head off. As Doug advised, look over your retainers and keepers. Make sure they match themselves and the valves. Might want to check that connecting rod for straightness also.

 

[Roman1970RR]

You dropped a valve at 3000 rpm. Unless the engine stopped instantly, you’re not going to like what you see when you take that head off. As Doug advised, look over your retainers and keepers. Make sure they match themselves and the valves. Might want to check that connecting rod for straightness also.

Yeah I’m bracing for the worst mate. The engine did cut out instantly I have Holley terminator efi I did wonder if it has a safety shut off of some kind but need to research more.

 

[Lefty71]

Someone called me last night with a similar story......valve spring failure at only 3000. They were looking for a complete rebuilder engine....as theirs was puking water and oil at failure.

 

[68Moparmaniac]

Thats a huge bag of suck right there brother... hope for the best and expect the worst.
If your lucky, the valve kissing the piston far enough away from the ring lands that your bore didn't get damaged, and the block won't be needing a sleeve. Like PRND21 said above "check the rods and crank" for damage. Either way brother I'm afraid your looking at a full teardown.

 

[1967coronet]

I can not add much except , Sorry man.

 

[PurpleBeeper]

If it were me, I’d try to replace just that valve/piston (& check the rod). You can pull 1 head and get at what you need without even pulling the engine

 

[68Moparmaniac]

If it were me, I’d try to replace just that valve/piston (& check the rod). You can pull 1 head and get at what you need without even pulling the engine

That my friend wouldn't be wise given the amount of possible shrapnel in the engine from that train wreck. If it were my car (nice ride by the way) I'd suck it up, yank that bullet and do it right before anymore carnage happens and that bullet becomes a boat anchor.....my 2c. Overall this is purely speculation since you won't know the extent of the damage until you tear it down. IF the bore is trashed and the rod's bent your into a full teardown anyways. At my age I'd rather work the problem on the engine stand than rolling around underneath the car knocking out the bad slug anyways. In the end it's all about what you can afford to do.... hotrods are fun but not cheap.

 

[lewtot184]

Pull the engine. If the valve dropped piston, head, and cylinder are most likely wrecked. You will be surprised at all the trash that will migrate thru the engine.

 

[PRHeads]

As said, looks like the keepers failed.
More than likely this is the result of some unhappiness in the valvetrain.
Careful inspection of the 15 other sets of keepers, and their related parts should help shine some light on if that’s true or not.

Also, if the cam lobe of the affected valve is going away, it can cause things like that to happen.

I’d also look for witness marks of contact on the outer edge of the retainer and the underside of the rocker.
Not only on the failed one, but the other 15 as well.

My experience is that it’s very rare to have keepers fail on their own.
However, if the valve, keepers, and retainer don’t all “lock” together, It usually doesn’t turn out good.

Even when the “inter-fit” between the parts is good, if there is high enough degree of hammering going on(from something like a worn cam lobe or dead spring), the tangs can get sheered off.

 

[WileERobby]

That my friend wouldn't be wise given the amount of possible shrapnel in the engine from that train wreck. If it were my car (nice ride by the way) I'd suck it up, yank that bullet and do it right before anymore carnage happens and that bullet becomes a boat anchor.....my 2c. Overall this is purely speculation since you won't know the extent of the damage until you tear it down. IF the bore is trashed and the rod's bent your into a full teardown anyways. At my age I'd rather work the problem on the engine stand than rolling around underneath the car knocking out the bad slug anyways. In the end it's all about what you can afford to do.... hotrods are fun but not cheap.

This ^. Sorry, but don't take chances, you never know what's lurking inside once you have broken metal.

 

[dvw]

I'd pull the head first. Many times damage is significant. But more than once I've been surprised at how little happened. If it didn't beak the valve it might not be as bad as some suspect. I do agree with checking the entire valvetrain.
Doug

 

[PRHeads]

It appears the valve stem is still in place.
Of course, the head of the valve may not still be attached.

The picture isn’t very clear, but the pushrod socket of the rocker looks like something may be going on there…….which is another indicator of possible valvetrain unhappiness.

 

[PRHeads]

The retainer at the rear looks like it might have a witness mark where it’s been contacting the underside of the rocker.

 

[ckessel]

The next thread down from this one may be beneficial to you if you need parts. One of your homies.
440 engine rear down. Anything worth keeping?

 

[PRHeads]

Here’s an example of keepers that had the tangs sheered off…….
There no indications of any problems on the other 15 valves/retainers/keepers.
The valve spring on the position that failed was down 30-40lbs from how it was installed.
The other 15 were still fine.

Before these keepers finally let go, they had moved up the stem to the top of valve, and there are witness marks on the top of them from contact with the rocker arm roller wheel.

So, the failure is a result of lack of control of the valve…….. because the spring lost a bunch of pressure, and that hammering finally won the battle over the tangs of the keepers.
The unanswered question remained……. Why did that one spring give up?

 

[Orig69]

Yes agree the valve is still there, just remove that one pushrod swing the rocker out of the way and try to see if the valve still moves freely.