Broken Valve guide

Roxo

Roxo

Senior Member
I discovered this by removing the valve cover to do a inspection. The only thing that came to my attention was #8 valve stem was kicked out of center on the tappet, away from the block by maybe 1/8". With my thumb I pushed it back into place. I could feel it pop into place. It was in the down position at this time.
both before and after I had turned the engine over by hand to verify all valves were moving up and down.
After replacing the head (Head was cracked) and putting things back together she started right up. But this time I had a tapping noise. So I opened back up and took out that valve. Here is what I found.
So now I guess my question is what is the best way to fix this one valve as the others seem to be just fine. My compression was in the mid to upper sixties when checked. Should I just replace the two piece guide?
Valve stem is not bent. No nicks or scratches.
 

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Try replacing just the guide and see if that works. If you had good compression in all four cylinders you should be good to go. Make sure valve is straight and seats evenly.
 
it is broken plus one side slipped down 1/8". here is a pic after I removed it.
 

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I don't know why this happened, maybe from a major backfire from #4 cylinder. Or bad product. I just purchased this truck back in September so I don't no it's history. The motor has been rebuilt, but when I don't know.
 
daveymc29 said:
Try replacing just the guide and see if that works. If you had good compression in all four cylinders you should be good to go. Make sure valve is straight and seats evenly.
Click to expand...

That is my plan to just replace the guide. Should I lap the valve just to be safe?
 
vernon said:
Could it be damage at rebuilding.
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That could be the case. I have know idea what kind of miles are on this engine, or how long that valve was hitting off center of the tappet. But yet it seem to seal ok, the #4 compression was 68. One of the 2 highest.
 
Replace the guide and while side is open inspect the other seven guides and valves. Definatly lap the valve with the new guide. Pictures dont show any springs holding the guide in place. Condition of hte springs? i would question the condition of the springs if they/it were not strong enough to hold the two sides of the valve guide in place.


BTW i have a box full of 2econd time around guides - still usable - cost of postage only.
 
Somewhere online a description of original springs - aged and new springs made to the Ford Spec - testing revealed that original springs had like HALF the Ford specified tension.

I would replace ALL the springs since you have it apart. Cheap money - and your engine will thank you.

Joe K
 
Thanks for the advice guys. Last night I ordered new guides and springs, lapping tool and compound. I did wonder If a weak spring was the cause of the guide moving out of place.
Do the guides just push up in place or is there a special tool for that?
 
Guides normally just push in place, but manufacturing inaccuracies, a burr on a machined edge, or a bit of rust or carbon can hold up the guide.

Be ready with a small drift to catch that edge where the spring mounts and give it a tap - but only a light tap as the guides are quite brittle and you may chip off the edge.

The spring goes on by lifting the valve to its full "up" position and then squirming the spring in under the bell-bottom of the valve stem.


Joe K
 
I just called Snyders and changed my order to replace all the guides, springs and Valves. Any advice on how to grind the valves for clearance?
That is something I have never done before.
 
If you don't already have adjustable lifters, take Flamingos advice. either way you'll have to grind the stem length as the replacements come a tad long. You will need to have a valve grinder and seat grinding kit to do it right and also something to practice on and someone to tech the technique. The machinery is big $$$ even for old worn out stuff and most of the mfg. are out of business for parts (Sioux). Tow it apart, down to the machine shop. Only way. Unless a neighbor has the equipment and skills. U-Tube is your friend if you want visuals of what needs to happen.
 
Yes I did a bit of research and I think I can make up a jig and grind at least one correctly to get this thing going. Would like to wait until next winter and install the adjustable Lifters.
I still need to drop the oil pan and check things out. If I find anymore problems I might just take the engine up to Skokie IL, (Antique engine rebuilding), and let them do whatever needs to be done. My cylinders are already bored out to .080. I don't know how far they can go before they need to be resleeved.
 
I would just replace the one guide for now, as replacing the lifters means removing the cam, which is a lot of work. You had good compression, so drive the car and enjoy it rather than looking for trouble if there is none.


Save your money and do a complete engine rebuild when it needs it.
 
Tom Wesenberg said:
I would just replace the one guide for now, as replacing the lifters means removing the cam, which is a lot of work. You had good compression, so drive the car and enjoy it rather than looking for trouble if there is none.


Save your money and do a complete engine rebuild when it needs it.
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X2...if I had a good running engine, with great compression I would change as little as possible to fix the noise. The guide for sure and the valve only if the stem is scored.
 
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