Can you tell me how this happened?

[Grabinov911]

Ok engine builders - Can you help me understand how this happened so I can keep it from happening again? I hadn't run the car in about a month and a half. I started it up in the driveway, warmed up for a minute and drove about a mile to the freeway on ramp. I got on the freeway and everything seemed fine. I'm in California so it was about 70 degrees out - the one good thing still remaining about California. I didn't romp on it and was never over 2,500 rpm (3.55 rear end with a gear vendors overdrive). When I got off the freeway 3 miles later I heard a pretty bad rattle from the engine. Enough that I pulled over at the Starbucks and had the car towed home on a flatbed. It sounded scary. When I pulled off the valve cover I found what you see in the picture. The pushrod is out of the rocker-adjuster "cup" and was just banging around under the arm of the lifter. That's the passenger side, front cylinder, second valve back. If I remember right that's cylinder number two, intake valve??

The engine is a 493 stroker built on a stock 440 block
Out-of-the-box Edelbrock Performer RPM heads
Crower Hydraulic Roller Lifters
Comp Cams Pro Magnum Roller Rockers
Custom length pushrods (can't remember the name of the company, but it's a good one)
Crower custom cam

The car is a street car with about 1,500 miles on this engine build. The cam is "lopey" but otherwise not particularly radical.

I disassembled the rocker assembly enough to get the pushrod out and it's straight as can be - at least it rolls perfectly on a granite countertop. I put it all back together and set the adjuster in exactly the same position as it is in the photo. And the car runs (at idle and up to 2,00 rpm in my garage) perfectly.

I'm NOT an engine builder...

What happened?

 

[WileE]

If it's not the cam, not the rocker, not the push rod, then...

 

[HEMI-ITIS]

I have seen that happen even with solid roller cam.In your case me thinks a lifter didn't pump back up fast enough leaving enough for the PR to fall out.Did your oil light come on?? I,ve seen that happen and the lifter came out and lost OP

 

[Grabinov911]

I have seen that happen even with solid roller cam.In your case me things a lifter didn't pump back up fast enough leaving enough for the PR to fall out.Did your oil light come on?? I,ve seen that happen and the lifter came out and lost OP

Wow! That wouldn't be good. I have Dakota Digital gauges and the Oil Pressure flashes if it goes too low. I didn't notice that but anything is possible. The car usually runs pretty high oil pressure - in the 60+ psi range. Hoping that I don't have a failing lifter, but the collapsed lifter seems like the only sensible explanation. It's working now though...

 

[Bb70charger500]

I agree with the lifter failure

 

[tomlin]

My bet is on the lifter. It was likely pushing on a valve the last time you shut down the engine. Eventually it bled down from the valve spring pushing against it. The next time you ran it r the lifter was bled down and you had a bunch of slack. That would cause the pushrod to fall out.

 

[Grabinov911]

My bet is on the lifter. It was likely pushing on a valve the last time you shut down the engine. Eventually it bled down from the valve spring pushing against it. The next time you ran it r the lifter was bled down and you had a bunch of slack. That would cause the pushrod to fall out.

You guys know way more about this than I do, but wouldn't the pushrod have fallen out immediately when the engine started? It seems weird that the engine ran well for about 10 minutes and THEN the pushrod fell out. Maybe the collapsed lifter wasn't an issue until I got up to higher RPM?

 

[Kern Dog]

The picture shows about 2 threads showing above the locking nut. That is correct and what you should have. Without a teardown, it is hard to diagnose 100%. I know you want to know the cause because stuff like this will affect your confidence about driving the car, right? If stuff just randomly fails, it makes a man want to drive a new car.
I have about 2500 miles on a set of 1.6 roller tip rockers from Mancini. Mine have not needed even a slight adjustment in that time. Now you have me wondering if I should check the lash.....
(Son of a bitch)

 

[J5 GTX]

You have custom length pushrods. Could the length be wrong? Near enough to run o.k. but, not o.k. with lifter bleed down.
Slim possibility that the valve momentarily stuck open and when the cam lobe went around to it's base circle the pushrod fell out.

 

[Grabinov911]

Yeah you guys read me well - it's all about confidence in the car. What if it happens at 4,500 rpm next time.

The car does have custom length pushrods, and all of the stuff was spec'd and checked by Blair's Speed Shop in Pasadena, California. they're one of the legit old time speed shops. They've been legendary in So Cal since the 50's. They've done this hundreds of times so I've got to believe they selected the right pushrods, and I've run it - even at Willow Springs Raceway - for 1,500 miles. I get what you're saying, but I can't really do any better than they did with the specs.

I'm going to start the car every day for a bit and see if I get any sign of it again. I wanna believe that it was the result of sitting around to long...

 

[69Bee]

Lifter should be okay as it ran for a couple of miles, and wasn't going nuts. I would have to lean towards a sticky valve. When the valve sticks, the lifter drops, and nothing is there to keep the pushrod in place. Is your gas stale from sitting maybe? Stale gas will gum up an intake valve in the guide faster than you can say "Holy Smokes". I had one set of GM 454 heads come in with all of the intake PR bent to hell. I asked if he ran it with stale gas, and he said yes. They were so bad, I had to use a propane torch to liquefy the gum just to get the valves out of the heads.

 

[Yatzee]

Ok engine builders - Can you help me understand how this happened so I can keep it from happening again? I hadn't run the car in about a month and a half. I started it up in the driveway, warmed up for a minute and drove about a mile to the freeway on ramp. I got on the freeway and everything seemed fine. I'm in California so it was about 70 degrees out - the one good thing still remaining about California. I didn't romp on it and was never over 2,500 rpm (3.55 rear end with a gear vendors overdrive). When I got off the freeway 3 miles later I heard a pretty bad rattle from the engine. Enough that I pulled over at the Starbucks and had the car towed home on a flatbed. It sounded scary. When I pulled off the valve cover I found what you see in the picture. The pushrod is out of the rocker-adjuster "cup" and was just banging around under the arm of the lifter. That's the passenger side, front cylinder, second valve back. If I remember right that's cylinder number one, exhaust valve??

View attachment 534285

The engine is a 493 stroker built on a stock 440 block
Out-of-the-box Edelbrock Performer RPM heads
Crower Hydraulic Roller Lifters
Comp Cams Pro Magnum Roller Rockers
Custom length pushrods (can't remember the name of the company, but it's a good one)
Crower custom cam

The car is a street car with about 1,500 miles on this engine build. The cam is "lopey" but otherwise not particularly radical.

I disassembled the rocker assembly enough to get the pushrod out and it's straight as can be - at least it rolls perfectly on a granite countertop. I put it all back together and set the adjuster in exactly the same position as it is in the photo. And the car runs (at idle and up to 2,00 rpm in my garage) perfectly.

I'm NOT an engine builder...

What happened?

I'm inclined to think the valve springs are too weak and this may happen again on a different piston. I doubt the valve would stick open as the cylinder would push it back up
unless the valve stem is slightly bent. And that's the second issue you may have. I fear to drive with confidence, that heads going to have to come off. That or roll the dice.

 

[Grabinov911]

BTW: Thanks to all of you

69Bee, Yatzee,

The gas has been sitting a couple months as well, but in CA I haven't seen it go bad THAT fast. But the car sits a lot - it could be an accumulation over time. I think a good can of fuel treatment may be in order. The car has 1,500 miles since the engine build, but that was over the 2+ years since the build (maybe should have mentioned earlier).

The valve springs are also custom. I remember the engine builder saying that the valve springs that came with the heads didn't spec out the way he liked for a performance engine and we bought new ones - and better keepers as well. So I have to give him the benefit of the doubt. I am going to have him take a look at that valve train and maybe pull off that rocker and spring. He should be able to tell at that point if the valve stem is bent I would think. Can you put a borescope down the spark plug well and see the top of the piston well enough to tell if it banged the valve? I would think so. All of that seems like it's better than pulling the head.

On the other hand, if I have to spend hundreds of dollars on a valve job maybe I should just spend $10,000, lower the compression and put on that Procharger I've been thinking about!!! I think I may be coming down with hemi-itis...

 

[Kern Dog]

Over the years I have heard the term "Sticky Valves" but I wonder how often that actually happens. Imagine a fresh rebuild like the OP has, stiffer springs like the OP has....How could a valve stick anywhere" The valve guides would be fresh, the valve stems fresh, the valve seats should have very little carbon build up.
In 2007 I had stock replacement stamped rocker arms in the 440/493. I drove it one day and it started rattling and running rough. Back at home I found 3 bent pushrods. One was bent like a Z ! I have no idea why that happened to this day. I had a MP 292/509 cam in there with stock pushrods. I just replaced the bent ones and the car ran fine again. Mysteries like this suck *** though. How the heck do you prevent these problems is you don't know what caused them???

 

[miller]

Two questions...

Crower Hydraulic Roller Lifters

Not familiar with hydraulic rollers, but that said...how much lifter pre-load? Still would believe it would be needed on those. If not enough, get slop in the valve train, especially with aluminum heads, since they 'grow' when warm.
Second, though from the photo, looks okay, rocker angles. From rocker arm to push rod, at 50% lift, should be 90 degrees. Is it good?

 

[Shorthorse]

My first guess would be a lifter collapsing. You said you started your car in the driveway and let it run. If the lifter was collapsed from setting you would have heard that at startup. There's no mistaking that sound. That doesn't mean it didn't collapse later while driving however. It probably happened quickly but do you recall hearing that distinctive ticking sound prior to real bad sounds?

I have a question for the smarter guys here.
It looks like ball/ball pushrods, I've never dealt with them. I'm wondering about the difference (in 1000's) of a fully pumped lifter and a collapsed lifter. So, if the adjusters have the cups, how deep does the ball go up into the cup? Can a preloaded lifter collapse enough to allow the pushrod to clear/fall out of the cup adjuster? Thanks

 

[Grabinov911]

I'd say the pushrod - lifter angle is near perfect. Every lifter on that side rotates roughly right through "center", at the 90 degree mark. The cam is a .582 lift, with a 1.5 ratio rocker. That should mean the pushrod moves .582"/1.5", .388", or roughly half of that from "center". That's less than a half an inch of total vertical movement of the pushrod, and it looks like it is doing exactly that.

They ARE in fact ball/ball pushrods - balls on each end. My builder said (I think) there is .400 or four hundred thousandths, which is more than 3/8", so that is WAY more than enough for the ball to fall out. Did he say/mean .040 or 40 thousandths? The lifter is a Crower 66341. The cup on the rocker-adjuster is very shallow, maybe in the range of 1/16".

I definitely didn't hear it on startup, and I didn't hear it on the freeway, but the car is pretty loud. Heard it on the off ramp.

Started up again today with no issues - in the driveway and at up to 2,000 rpm in neutral. No lifter rattle.

 

[J5 GTX]

Valve could be stuck open from a foreign object temporarily holding the valve open. Could be some of the rattle you heard was something banging around in the cylinder????
But, I would think with the amount of lift of your cam that the valve would have struck the piston, hence it wouldn't run smooth later.

 

[miller]

The cup on the rocker-adjuster is very shallow, maybe in the range of 1/16".

Maybe just me, but the adjuster cup sounds too shallow. Don't know if you have any choices on the adjusters, so a deeper cup could be used. At least, with the adjusters, you can set the pre-load, as you want it.

 

[Grabinov911]

After discussions with a couple of mechanic buddies and a really good Youtube video I went ahead and checked the lash on every rocker on the engine. Many of the pushrods were pretty loose with the lifter on the base of the cam. Everyone agrees that a pushrod should not be loose on the base of the cam (valve closed) on a hydraulic lifter motor. Some of mine were so loose that not only were the pushrods able to spin but they had a small amount of vertical play in many cases. The video suggests they shouldn't even spin.

I also read the Comp Cams Pro Magnum Rocker instructions (read the instructions if you can believe that) which say that they are looking for 0 lash plus a half turn. So I figured that 0 lash WITHOUT that half a turn of preload was certainly safe enough for me to get the engine running smoothly and take it to my builder for a checkup. So I tightened every pushrod to where it was just too tight to spin with oily fingers. I like the point that the video makes that you don't really need to know where TDC is (for a 0 lash adjustment on a hydraulic lifter motor). You simply keep checking until you NEVER find a pushrod that is loose no matter what the position of the engine, and you never tighten a pushrod unless it is loose. The pushrod is by definition never going to be loose when the valve is open because IT is holding the valve open. So it can only be loose on the base of the cam, and it should never be loose there.

The engine runs great. That said, it's still going in for a checkup. I'm a Youtube mechanic, NOT a performance engine builder!!!