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Disaster, almost

dvw

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FBBO Gold Member
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waterford mi
First off let me state God was watching over me. In my last post we were in trans repair mode for the sprag. Now reinstalling the trans. Rotating the crank to install the 3rd converter bolt, crank stops, dead. Won't move either way more than 2-3 degrees. Don't want to force it backward with the Jessel belt. Pull the dist and oil drive, pump spins, losen the alternator (brand new) and vacuum pump belts, nope. Pull all the rockers and pushrods. All look great. Lifters can be pulled up with a pthe spragiece of tig rod. Now the crank will rotate counter clockwise about 300 degrees and then, stops dead. Pull the trans back out to make sure something didn't hang up in the flexplate. I mean it was fine when the crank was rotated to pull the trans, right? Found nothing. Tried a bore camera saw nothing. Rreinstall the trans and pull the pan. Everything looks good. Pistons # 4 &# 7 won't clear TDC about 30 degrees either side. Take a guess at #4 1st. Pull the header. Pull the exh valve spring and replace with a checking spring. Try the camera and see nothing. I'm lost. Decide to pull the passenger head. Pull the intake. One last gasp. Pull the intake valve spring and swap with checking spring. Push the valve open. What do I see. A undamaged 5/16" nylock nut setting on the piston below the exhaust valve. Where did that come from? Only thing I can think of is when the accumulator was relocated during the alternator upgrade. It's the only item thats been removed that uses that nut. Engine had been started several times to check the alternator. Then moved into the hoist bay. Then started again after the oil change. I really hadn't cracked the throttle far until then. No marks on the piston. Cylinder leaks 5% cold. Not all a total loss of time. The screen windage tray was cracked again. So thats not going back. I'll fab a baffle above the pick up. The intake gaskets are climbing the head, again. So I'll replace them as well. First race is in 2 weeks.
Doug

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wow man.. that could have been sooo bad.. you have some luck going on...

BTW.. what's making that gasket creep up like that? just vibration and squish? I could see it with boost but seems odd with NA
 
Glad you caught it. Pretty crazy it’s in there and did no damage
 
That was time well spent... Good thing you caught it.
 
First off let me state God was watching over me. In my last post we were in trans repair mode for the sprag. Now reinstalling the trans. Rotating the crank to install the 3rd converter bolt, crank stops, dead. Won't move either way more than 2-3 degrees. Don't want to force it backward with the Jessel belt. Pull the dist and oil drive, pump spins, losen the alternator (brand new) and vacuum pump belts, nope. Pull all the rockers and pushrods. All look great. Lifters can be pulled up with a pthe spragiece of tig rod. Now the crank will rotate counter clockwise about 300 degrees and then, stops dead. Pull the trans back out to make sure something didn't hang up in the flexplate. I mean it was fine when the crank was rotated to pull the trans, right? Found nothing. Tried a bore camera saw nothing. Rreinstall the trans and pull the pan. Everything looks good. Pistons # 4 &# 7 won't clear TDC about 30 degrees either side. Take a guess at #4 1st. Pull the header. Pull the exh valve spring and replace with a checking spring. Try the camera and see nothing. I'm lost. Decide to pull the passenger head. Pull the intake. One last gasp. Pull the intake valve spring and swap with checking spring. Push the valve open. What do I see. A undamaged 5/16" nylock nut setting on the piston below the exhaust valve. Where did that come from? Only thing I can think of is when the accumulator was relocated during the alternator upgrade. It's the only item thats been removed that uses that nut. Engine had been started several times to check the alternator. Then moved into the hoist bay. Then started again after the oil change. I really hadn't cracked the throttle far until then. No marks on the piston. Cylinder leaks 5% cold. Not all a total loss of time. The screen windage tray was cracked again. So thats not going back. I'll fab a baffle above the pick up. The intake gaskets are climbing the head, again. So I'll replace them as well. First race is in 2 weeks.
Doug

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live in fear of that .
 
Wow! More than luck. Good problem solving and investigative skills. Just the same, I think this would be a good time to buy a lottery ticket, Doug.
 
A locking nut just doing its intended function :D




Sort of
:lol:
 
I see I'm not the only one that has those pesky gremlins that cause trouble in the shop.
I swear they come out at night...
 
Wow, glad you found it before any damage.
Reminds me of a time a co-worker brought his 81 Grand Prix with a BBC in it to the job site for the day on a Friday. He pops the hood and removes air cleaner and threads wing nut back on for us to check it out. He fires it up and revs it several times, we notice the wing nut backing off as he revs it. As we react, one reaching for the wing nut, another telling him to shut it off. It drops down the carb on the last rev. He shuts it off immediately.
We find no wing nut in the carb. I tow him home with a tow rope. We remove carb that night. Not in the intake. We remove the intake. Not in the heads. We remove the first head, then the other. No damage, no wing nut? Lifted engine and pulled pan. Still no wing nut?
6 of us watched it fall down the carb. He put it back together and drove it back to work on Monday.
He never found the wing nut????
He thinks it spit out the exhaust and is probably in the muffler. It never made it to the ground.
He was still driving the same car even after I quit working there.
 
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Years ago I had a similar experience where I shut the engine off and heard something rattle… sounded like a tink clink tink tink under the hood, hard to describe. Anyhow, upon startup there was a definite rattle and the investigation began. One of the screws from the underside of this Predator carb backed out and was bouncing on top of a piston. Dropped the problem valve down as Doug did and was able to get it with a magnet. I buttoned it back up and the thing ran great for 10+ years.

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And the saga continues. Just caught this on a glimpse. I have another cam I was going to try next time around. Guess that time is now. Fortunately the rockers and intake are still off.
Doug

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Get that lottery ticket today. That was a disaster waiting to happen.
 
I have a billet roller that looks just like that in several places. (It was a freebie from a friend in case I wanted to repair and regrind it.)
We decided it was from valve float/tired springs in his case. He overrevved his rat motor on a regular basis.
 
Man, now you’re going to have to scramble to get ready for the start of the season
 
Cam is out. In my assy notes from the build in 2021 it was noted the #5 int lobe had some pitting. Fortunately the lifter appears fine. This engine has never been over revved. Valve spring pressure is monitered on a regular basis.
Doug

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