"Daymond – did you build-out t
"Daymond – did you build-out the long block or did a shop do it (transfer of old parts to new that is)?
Re: your question about the likelihood of internal damage……your answer to David’s questions about the sounds, etc. is a bit concerning. Given the craft, I’m guessing that 30 minute run has some “spirited” driving in it. If the issue existed, or was building, that entire time (or even a fraction of it), you may have built up a massive amount of internal engine pressure……because the crankcase “fluid level” (oil and water) continued to build with no way of evacuation. Not to mention that you’re less protected from the heat and friction as the oil becomes more diluted. If you heard metal……not good (could be oil pump gear teeth, could have been the seizure of any number of components).
My block cracked over the winter and, when I started it up this spring, it took only a minute or two for the milkshake to come out my dipstick tube……and that’s at idle on a garden hose. I subsequently stripped every last component off of that block and, although almost every part was salvageable there are some parts that are still coated in that mess. So, even if the engine survived, it’s going to take many, many rounds of flushing and each one is dangerous….because watery oil is still in the bearing areas, etc.. Some would argue that the only safe way of salvaging those internals is to yank the motor, pull it apart and clean each component (vs. running it, changing the oil, running it again, etc.).
The reason I ask about the build-out is because there’s some other things, besides exhaust, that could cause the water intrusion. If the intake manifold was not installed properly, and the water passages weren’t well sealed, you’ve got one of the largest and most direct passages into the crankcase.
There can be different symptoms between intrusion through the risers vs. the manifold. When going through the risers, you’re getting water going down through the cylinders themselves. If it’s a slower or isolated leak, you might notice the engine performing poorly in advance of it shutting down…..from the affected cylinders misfiring (or not at all). A direct crankcase intrusion (i.e., intake, cracked block, etc.) can allow the engine to run normally (seemingly) because the piston rings are still protecting the combustion chambers. So, these those types of intrusions can often end in a more abrupt/sudden failure (friction, pressure, etc.).
I feel for you man…..especially with everything involved in dropping in a new motor. I hope you can salvage it. Keep us posted."