RLS7201 wrote:
454s have some history of antifreeze leaks from head gaskets and intake manifolds, causing hydro lock. Hydro lock can cause broken crankshafts, bent rods and broken pistons. I have personally been involved in the repair of two such cases of hydro lock.
Richard
I have never heard of this happening except on boats for obvious reasons. The 454 is a very popular marine power plant. I googled it to see if it's a common problem with the 454 or any other engine in particular. It just isn't.
There was no evidence of a head gasket leak on mine when the #3 piston came apart. You would have to have a massive, instantaneous intrusion of coolant in order to hydrolock an engine. Not saying it can't happen, but it's virtually impossible without very obvious signs of a head gasket leak over a very long period of time or some other catastrophic failure that causes the head gasket to blow. I had a Grand National that a shop apprentice stole after hours. He ran 30 PSI of boost through it street racing without knowing how to operate the alcohol injection system. The head gaskets on both sides blew in about 4 different places. But it didn't hydrolock. Beat the **** out of the crankshaft and main bearings but that was from detonation, not coolant intrusion into the cylinders. (yes I sued the shop owner, no I never got paid. Cost me $6k to fix it). But I digress....
The worst cases of poorly designed head gaskets I've come across in my shade tree mechanic life are on the older dodge inline 6s (like in the K-cars) and the Nortstar V8s. I've had several and none ever hydrolocked. They'd lose coolant at an alarming rate - but they'd burn it. Never hydrolocked. Ironically I did have an '86 T-bird with a nasty head gasket leak that I drove that way for years. It did hydrolock after going through a deep puddle in front of my house. Thankfully I wasn't going very fast. I was able to pull the plugs, crank it over a few times, put the plugs back in and start it up. I was only 15 minutes late for work!
Again, not saying it can't happen but I wouldn't consider it common and to say 454s have a "history of it" is just plain misleading.