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Discussion Starter · #1 ·
Was pulling in the garage at low RPM then all of sudden bang, spring broke on exhaust side 8th cylinder. Ran like that for 5 seconds.

The bad part is the whole spring area fell apart and the rocker somehow hit the valve covers sending metal shaving of the valve cover everywhere. Valve was still up when the valve covers where removed but unknown if it had dropped and the piston simply slapped it back up?

Would metal shaving like this cause me to disassemble to find every piece and clean every valley.

What would you do? This is 347 stroker with 60 000 Km (not miles), burns oil through the intake from the pvc.

Any tips on where to start would be great.







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I'd start with trying figure out why the spring broke...
x2

If all Things look good & what you have to do to get it running is putting in a New spring/ Assembly, I'd clean out the aluminum shavings and run it. Did that when rockers hit valve covers that were too low.... And the engine still runs great..... A bit of Luck, ofcourse. Soft aluminum shavings are nothing to be worried about, or?

Seriously, depending on the amount of metal missing, you should consider dissasemble & clean. Look at how much is missing and how much you find in Your head... Maybe it's all there.
 

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Discussion Starter · #5 ·
Thanks

Been looking at everything on what could of caused the spring to break. No evidence of binding or over tension, weakness or even rust spots. Just a clean break due to maybe age. Who am i trying to fool, if I dont dissasemble I will be worried I missed some of the metal shavings all the time.
 

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Discussion Starter · #7 ·
Cam was comp cams custom from previous owner so unknown. (run for 4 years)1.7 Ford rollers with perfect valve contact pattern and GT40y heads. Comp cam push rods measured to fit. But seems that the push rod is slightly bent, maybe improper shim of the rockers.
 

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Cam was comp cams custom from previous owner so unknown. (run for 4 years)1.7 Ford rollers with perfect valve contact pattern and GT40y heads. Comp cam push rods measured to fit. But seems that the push rod is slightly bent, maybe improper shim of the rockers.
hello;

how old is the gas?

the push rod is bent because either the valve hit the head or it stuck in the guide.

if it simply stuck in the guide after 4 years it is likely eityer from 0verheating or bad gas gumming up the guide.

is it a roller cam?
.
 

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Cam was comp cams custom from previous owner so unknown. (run for 4 years)1.7 Ford rollers with perfect valve contact pattern and GT40y heads. Comp cam push rods measured to fit. But seems that the push rod is slightly bent, maybe improper shim of the rockers.
It is unlikely, with the keeper laying on the head, that the valve isn't bent. This is especially true if the pushrod is bent.

I'd run a leak down test on the cylinder that lost the valve spring assembly. My bet is it will blow air out that valve.
 

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Discussion Starter · #10 ·
Thanks, I will leak down test and go from there. Gas is new and as always been kept fresh. Question: why would the rocker which did not hit the valve cover to start with all of sudden hit the cover after the broken spring. And if it passes leak down do i simply run a bucnh of oil through it and get as much of the debris out. New springs on the whole head of course.
 

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I lost some metal in the engine due to valve train issue of my own doing. I thought I got it clean as could be.. A shaving wasn't washed out, got past the screen and seized my oil pump, snapped the oil drive shaft the went to the dizzy. Was cruising 70 on the freeway

I have the engine apart now just cause I feared a shaving got loose from cam damage (valve float maybe?) I didn't find any but I won't chance it anymore. This is the damage, in my case metal would be minimal
 

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Haha to scare is not the intent, but it did happen to me and I learned the hard way. Lucky I was not far from home and it didn't result in major engine damage

At minimum in your case I would pull the pan maybe look at the oil pickup.

Sadly non of that tells you about what happened at the valve spring
 

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Discussion Starter · #14 ·
Im taking a guess as to simple wear and tear. Because nothing points firmly in any direction. Thank yoyu all for the advice given i belive I have a planned path to take based on your comments.
 

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Thanks, I will leak down test and go from there. Gas is new and as always been kept fresh. Question: why would the rocker which did not hit the valve cover to start with all of sudden hit the cover after the broken spring. And if it passes leak down do i simply run a bucnh of oil through it and get as much of the debris out. New springs on the whole head of course.

The rocker hits the valve cover for one of two reasons:

1.) The pushrod acts like a spear being thrown by the cam, and no spring to stop the wayward movement or downward movement of the valve

2.) The push rod comes out of the cup recess, and pushes elsewhere on the rocker body where it lifts it more.

You can clean the head up first and flush the system with a lot of diesel fuel or kerosene if you are brave or lucky. You run a risk of real problems if you don't have a good fine mesh screen on the oil pump pickup or something small stays in the system.

I think you will be taking it apart, though. I think it is pretty likely the valve is bent.
 

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Discussion Starter · #17 ·
Thanks, everything leads to take her apart and make sure. A 347 isn't cheap so I would like to keep the motor. I will let you all know what I find as to document the symptoms with the effects for anybody else looking for info.
 

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