Hello, I just picked up a late 1950's buehler turbocraft jetboat with a 312 interceptor in it.  It has been sitting for say 20 years, the boat was covered for about half that.  Engine compartment was alwasy covered, but boat doesnt have a drain plug :-(  ownere drilled a small hole several years ago.  Engine is seized solid.  Starter is seized solid.  Alternator is seized solid.  The whole oil pan mush have sat in water for a while and froze.  IT's cracked the whole way around on the curve.  Hoping this engine isnt fried, but it looks bad.  Original goal was to do a partial restore of the boat to get it in the water and having fun, but looks like I need to pull the engine and do a ton of work.  I"ve never done an engine rebuild(inboard, I"ve done quite a few single/two cylinder outboards).  How screwed am i?  Assuming the camshafet and bottom of the rods have been sitting in several inches of water for years....Heck the oil pressure gauge on the side of the motor even is full of rusty water....

The entire rest of the engine(intake, cabs, exhaust manifolds, etc) all looks good.  Peering thorugh the oil fill in the valve cover, its still shiny and clean!  I"m not sure if this had been rebuild already as the mixed color parts of the block and the rest of it?  I dont know if it makes more sense to part the thing out(I have tons of parts that came with it) and repower, or attempt a budget rebuild.  I have 2 young kids and not a ton of extra cash at this point in my life...

Any input or help would be much appreciated, thanks!  PS.  HELP!

If you’re a wooden boat guy, you know the drill already. I’d get the engine out, and see if the intake, heads, exhaust manifolds, etc will come off without breaking any frozen bolts. From the sounds of it, getting the valves out might be a problem. Down to a short block, you’ll be able to see what’s there, and if it’s worth going any farther. I know the old trick with flatheads was to put them in a barrel of diesel fuel and let them soak for 6 months or so.

Once it’s out you’ll be able to check the casting numbers, main caps, etc. and see what it is. All y blocks are 312’s of course, just like all scrubies are Vette engines.

John Mummert’s site has a pretty good selection on casting info, and how to identify the real 312’s. I don’t know there’s much on boat engines. Here.

http://www.ford-y-block.com/

Depends on what you can salvage, and maybe there’s a good 292 local to you to swap the marine parts onto. Otherwise, on a budget you’re looking at an engine change to a more modern power plant.

As a kid with my Dad, I was involved in 27 marine engine changes, mostly twin screws in the 36-50 foot range. Several Chris Crafts, and Owen, and others. The smell of varnish, no matter how pretty it is, still runs me away.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

Thanks Mike.  Unfortunately my experience has been mostly with outboards(other than one lunger diesel sailboat engines), so this is all new to me.  I had planned on filling the thing with marvel and letting it sit for the winter, but the oil pan missing the bottom put a damper on that!  Honestly everything under the valve cover looks super clean, and almost 0 rust.   The think I"m really owrried about at this point is the crank and bottom of the rods.  You can almost see a line on then engine where the water sat for years, and though yes, I"m sure theres a ton of moister in the top side, I've got my fingers crossed its not enough to cause a total loss.

I"d prefer to rebuild this guy, or find a similar engine on the cheap.  The older gentleman I got the boat from has another matching 312 that is in another boat on his property and the bottom of the boat has a huge hole in it, so we know it hasnt sat in water--Unfortunately he is headed south for the winter already, but has offered to give it to me in the spring.  Maybe between the 2 I can cobble something together?  I want to do as much, if not all the work myself.  IT doesnt have to be 100% perfect, just running and reliable.