Tales From The Borescope

[Don67Satellite]

Got a cheapie borescope to peek around with and took a gander inside a couple spark plug holes.

Wondered what the guru's think about the tops of my cylinder walls and what causes that. Is it normal? Leaky valves? Just curious.

'78 motorhome 440, bottom end was "refreshed" by the PO (needed a new crank), 452 iron heads. This streaky buildup is only at the top of the bores in the couple cylinders I peeked in, but I haven't looked in them all yet.

Thanks in advance.

 

[1 Wild R/T]

Take the carb off & look down the intake passages.. Pay close attention to the joint where the intake becomes the cylinder head.... I could be wrong but I'm betting the cylinders that show the most streaks are gonna show oil coming past the intake gasket...

 

[Don67Satellite]

Take the carb off & look down the intake passages.. Pay close attention to the joint where the intake becomes the cylinder head.... I could be wrong but I'm betting the cylinders that show the most streaks are gonna show oil coming past the intake gasket...

I did have a bad intake gasket a few months ago, was getting oil on top of the valley pan as well. When I changed the bathtub I also changed intakes. Pretty sure everything with the intake is (currently) sealed.

I'm quite sure by the appearance this is not new so could have had something to do with the bad gasket/bathtub I removed.

 

[toolmanmike]

I would do a carbon blast. It won't hurt anything if you leave it. It's above the ring seal.

 

[Don67Satellite]

Thanks @toolmanmike & @1 Wild R/T for the responses. Doesn't sound too serious.

I am planning a refreshed set of heads over the winter as the current 452's look like they have never been.

 

[AR67GTX]

I peeked in a couple of the cylinders of my 440 and was so surprised and demoralized by the chipped piston edges and light scoring in the walls of those that I just quit. Engine runs strong, doesn’t smoke and never needs oil. Decide to leave well enough alone and pretend I never looked.

 

[toolmanmike]

I peeked in a couple of the cylinders of my 440 and was so surprised and demoralized by the chipped piston edges and light scoring in the walls of those that I just quit. Engine runs strong, doesn’t smoke and never needs oil. Decide to leave well enough alone and pretend I never looked.

Yep. If it ain't broke!