[radarman]

I had a similar problem wit the gasket between the riser and manifold. Leaked the fresh water into the cylinders. Lucky for me! SHIT. But I never had the engine compartment fill with steam-or smoke. It would go out the exhaust. If the engine compartment is steaming sounds like a hose.

1. Pull the plugs and check for water. If you have wet plugs you have water (hopefully fresh) in the cylinders. This is bad but not disastorous if fresh water. Water can leak in from the riser gasket. Sometimes you can change manifolds and risers and get new gaskets and the engine will be okay. If it's saltwater cooled you're doomed.

2. Got rust around the riser and manifold? Probably time to replace the risers and manifold. They can spring a leak due to corrosion and you're doomed. Saltwater will run into the cylinders and bye-bye!

3. If you're compartment is filled with steam (not smoke) you've got a busted hose and the water is hitting the hot surfaces causing steam. I'd pull the plugs first and if they're dry fill the water again and look around for a leak. It ain't fun and it ain't pretty and you're back will be sore from humping that engine. But, I hope you get off cheap. Those valve jobs and engine overhauls are pricey even when you do them yourself!