Unfortunately, I couldn't quite get my iPhone into the port to provide a better view of the backside of the valves, but none of them looked visibly bent and they all looked undamaged with no witness marks when I climbed into the engine compartment and put my eye up to each port with a flashlight.
I thought it was interesting how much oily carbon there was on each valve stem, and one valve looks like it has a puddle of oil sitting on top of it - hmmm.
And the #8 cylinder port showed a couple of shiny dots/spots in the inside wall of the port which leads me to believe the stud might have gone down this hole and banged around the inside of the port before being sucked into the cylinder.
I sent a message to some fellow club members to see if anyone has a borescope so I can get a look-see through the spark plug hole. If no one has one, I might just pick one up at Harbor Freight - now where's that 20% off coupon I had from last Sunday's paper?!
This is really frustrating! And looking like it might be expensive.
I thought it was interesting how much oily carbon there was on each valve stem, and one valve looks like it has a puddle of oil sitting on top of it - hmmm.
And the #8 cylinder port showed a couple of shiny dots/spots in the inside wall of the port which leads me to believe the stud might have gone down this hole and banged around the inside of the port before being sucked into the cylinder.
I sent a message to some fellow club members to see if anyone has a borescope so I can get a look-see through the spark plug hole. If no one has one, I might just pick one up at Harbor Freight - now where's that 20% off coupon I had from last Sunday's paper?!
This is really frustrating! And looking like it might be expensive.
Hello Garth; What do the exhaust valves look like?!
Have you attempted rotating the engine via a socket & breaker bar on the crankshaft head bolt?
On aside note...I have PLENTY of 20% off Harbor freight coupons if you want to pick some up.
There is a Harbor Freight on Stevens Creek road Cupertino, just a mile away from my double wide trailer...Mark
Have you attempted rotating the engine via a socket & breaker bar on the crankshaft head bolt?
On aside note...I have PLENTY of 20% off Harbor freight coupons if you want to pick some up.
There is a Harbor Freight on Stevens Creek road Cupertino, just a mile away from my double wide trailer...Mark
No damage to the plugs either?
I use a bolt to secure my air cleaner. A bit of a PIA to get started though. A nylock wing nut would retain a loose stud too.
I use a bolt to secure my air cleaner. A bit of a PIA to get started though. A nylock wing nut would retain a loose stud too.
[QUOTE]Originally posted by larryw:
No damage to the plugs either?
Good point, and one that I forgot to mention...the first thing I had done to check for damage is pull a plug. The very first plug I pulled was #8 and it was a mangled mess. All the others were OK.
Pull those plugs, Garth!
No damage to the plugs either?
Good point, and one that I forgot to mention...the first thing I had done to check for damage is pull a plug. The very first plug I pulled was #8 and it was a mangled mess. All the others were OK.
Pull those plugs, Garth!
Update...
All plugs pulled, and all look great! No mangled electrodes, and nice consistent color across all the plugs.
All plugs pulled, and all look great! No mangled electrodes, and nice consistent color across all the plugs.
I picked up a Centech Digital Inspection Camera at Harbor Freight tonight - the cheap $89 one, and used a 20%-off coupon as well.
I had borrowed a friend's Milwaukee inspection camera, but the camera end was too large to peer into the cylinders. That's why I bought the HF unit. You can see both cameras in this picture. The HF unit has a much smaller camera/head that easily fit through the plug hole to inspect each cylinder.
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Please excuse the quality of the pictures that follow. They are rather poor because I bought the cheap $89 borescope that doesn't capture pictures or video, so I used my iPhone to take a picture of the screen. The HF inspection camera that could take pictures and video was $199, about $110 more than I wanted to spend!
Anyway, only #8 shows any signs that the air cleaner stud may have gone into it. This is the underside of the head, and it appears like an imprint of the threaded air cleaner stud in the head adjacent to the valve seat. No discernible marks on the valve though, although difficult to determine with the borescope. And to be honest, the image on the borescope screen was much sharper than this image - I think I may have had the iPhone a little too close to the screen.
Anyway, only #8 shows any signs that the air cleaner stud may have gone into it. This is the underside of the head, and it appears like an imprint of the threaded air cleaner stud in the head adjacent to the valve seat. No discernible marks on the valve though, although difficult to determine with the borescope. And to be honest, the image on the borescope screen was much sharper than this image - I think I may have had the iPhone a little too close to the screen.
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is the crank still "stuck" or have you rotated it either backward or forward yet. Is the #8 exhaust valve visable and closed
I haven't rotated it yet. That's the next step. I'm also planning on pulling the valve covers to examine the rocker arms and their movement as I rotate the engine by hand.
Just a thought .. if you've determined that the damage is just on one side why not bite the bullet and pull that head. You'll certainly get a better idea of the damage and you are going to have to pull it anyway based on what you've seen.
quote:You'll certainly get a better idea of the damage and you are going to have to pull it anyway based on what you've seen.
Definitely plan to pull that head. And thank you for pointing out the obvious - I'm planning to pull the head anyway, so no point wasting time with the other investigation activities. Thanks for that reality check!
Garth, you may have gotten lucky with the broken stud blowing out the exhaust with only minimal damage to the engine. If so, the stud will wind up inside your muffler. If it did, during idle when engine noise is minimal and engine shake is max, you may hear an annoying little jingle from one muffler.... The only way such a noise can be eliminated is to cut open the muffler body and dig around until you find it.
Too late this time, but making up a gr-5 stainless steel stud will fix things for next time. Stainless is tougher than mild steel and will not work-harden from vibration. Lock-tite along with a locknut keeps the threaded bottom secure in the carb boss.
Too late this time, but making up a gr-5 stainless steel stud will fix things for next time. Stainless is tougher than mild steel and will not work-harden from vibration. Lock-tite along with a locknut keeps the threaded bottom secure in the carb boss.
Let us know when the "engine pull party" will be :-)
Well, I found the air cleaner stud! Pulled the head off today and found the stud stuck in the intake valve, between the valve and seat. Tonight I'll measure the piston to deck clearance and compare with the adjacent cylinder to determine if the rod got bent.
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