I recently bought an older deck boat with a Merc 260, (GM V8 350), the starboard side exhaust manifold has a crack that seems to be cracking under high load and then rusting shut again. When it is leaking, it's a slow drop or at least that's the worst I've ever seen.
My initial plan was to JB Weld it. After some research I found another topic discussing this on a Ford and it was brought up that this could somehow ruin the engine if the entire manifold isn't replaced?
My question is; how likely is that to actually happen? The crack appears to be on the outside of the Manifold, how could this cause engine damage?
On my engine, how could the water end up back into the engine block? How common is that?
Any opinions on good fix? JB Weld/Weld/Replace Manifold?
Right now, it's running great. It was running sketchy so I pulled the distributor and the points were burnt up. Replaced with Pertronix Ignitor II electronic ignition and Flame Thrower II coil 45,000 V 0.6 ohm. Replaced plug wires with premium Sierra MagForce and plugs with NGK BR6FS gapped just over 0.35. Set timing and settled on 9.5 BTDC. It's running great.
My initial plan was to JB Weld it. After some research I found another topic discussing this on a Ford and it was brought up that this could somehow ruin the engine if the entire manifold isn't replaced?
My question is; how likely is that to actually happen? The crack appears to be on the outside of the Manifold, how could this cause engine damage?
On my engine, how could the water end up back into the engine block? How common is that?
Any opinions on good fix? JB Weld/Weld/Replace Manifold?
Right now, it's running great. It was running sketchy so I pulled the distributor and the points were burnt up. Replaced with Pertronix Ignitor II electronic ignition and Flame Thrower II coil 45,000 V 0.6 ohm. Replaced plug wires with premium Sierra MagForce and plugs with NGK BR6FS gapped just over 0.35. Set timing and settled on 9.5 BTDC. It's running great.