Can I save this engine?
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Joined: Nov 2012
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Can I save this engine?
Some of you already know my 390 woes. I finally opened her up after a strange sound brought me to a sudden stop at the beginning got the month. This is what I found in my #8 cylinder. The valve seat had snapped right off. The stem was still in place but hung out just a little and the retainer and clips were still in the head.
The piston head looks pretty good to me. There is only one scar and it is not very deep--see pics. I was hoping to replace the valve and clean up everything then replace all of the gaskets, and go for it. Or replace the head altogether if that is a better option.
I still have to remove the oil pan and check the rod for that piston, but I stopped immediately after I heard the noise. I'm looking for second opinions here. What do you guys think?
The pics are loaded in profile albums.
The piston head looks pretty good to me. There is only one scar and it is not very deep--see pics. I was hoping to replace the valve and clean up everything then replace all of the gaskets, and go for it. Or replace the head altogether if that is a better option.
I still have to remove the oil pan and check the rod for that piston, but I stopped immediately after I heard the noise. I'm looking for second opinions here. What do you guys think?
The pics are loaded in profile albums.
Senior User
Joined: Oct 2005
Posts: 130
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Wonder why that happened? Over rev? Or very worn out valve springs? Do you know if the cam is stock?
I would attempt a rebuild, it doesnt look too bad, as long as it didnt score the cylinder wall. Sometimes a hit like this can pinch the ring land and make a ring stick but it is hard to say...
I would at least try and rebuild it. Pop in a new valve but try and figure out what happened? Valve could have also stuck open, but I would be concerned with why this happened when I put it back together..
I would attempt a rebuild, it doesnt look too bad, as long as it didnt score the cylinder wall. Sometimes a hit like this can pinch the ring land and make a ring stick but it is hard to say...
I would at least try and rebuild it. Pop in a new valve but try and figure out what happened? Valve could have also stuck open, but I would be concerned with why this happened when I put it back together..
Hotshot
Joined: Apr 2009
Posts: 14,333
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From: Stanley, VA
Just so you know the proper terminology, the valve head is what broke off. The valve seat is where the valve sits in the head when its closed.
The cylinder and piston look okay. How does the head look? Is the valve seat damaged or scarred? If its mildly damaged it can be refaced. If its gouged, a machine shop can install a replaceable seat. In this case it might be cheaper to replace the head.
The cylinder and piston look okay. How does the head look? Is the valve seat damaged or scarred? If its mildly damaged it can be refaced. If its gouged, a machine shop can install a replaceable seat. In this case it might be cheaper to replace the head.
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weverette1
335 Series- 5.8/351M, 6.6/400, 351 Cleveland
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Mar 5, 2005 04:50 PM
