Helped a buddy pull a Holman-Moody 302 Ford out of his 1970 Donzi sweet 16 yesterday. He had already pulled the heads and manifolds, so we pulled the block assembly and took it apart. In the oil pan was about a half a cup of apparent cooling system debris, iron oxide chunks looking like corroded iron bits from water jackets.

Can't figure out how cooling system debris could make it into the oil pan when there isn't any signs of water jacket damage and no water in pan. It kind of looked like the cooling system debris hadn't been there long since it didn't look like any had made it to the oil pickup screen. But since the cast aluminum pan has baffles, the debris may not have had a route to the pickup anyway.

Looking for solutions to this mystery. The motor looks like it has never been out or apart. Thanks

Not a mechanic, but wouldn't that suggest a head gasket and make debris likely from pan, block, or internals?

Check the timing cover for corrosion.

quote:

Originally posted by shovelhead:
Check the timing cover for corrosion.

It's an iron casting, and no signs of deterioration. Many chunks were about split dried peas sized.

By an chance does that engine have an internal water pump (one built directly in the engine block)? Catastrophic failure could dump tons of coolant directly into the oil sump.

Maybe they're just corroded iron bits from the oil galley and passages.

quote:

Originally posted by cas:
Maybe they're just corroded iron bits from the oil galley and passages.

No bearing scoring indicating any debris ever went through lube system.

quote:

Originally posted by pbslinger:
...any debris ever went through lube system.

But it made it to the pan... which is part of the lube system, it couldn't have gotten there any other way (unless someone dropped the pan and put it in)

quote:

Originally posted by shovelhead:
Check the timing cover for corrosion.

This and is this a closed coolant system or open and are the exhaust manifolds wet?

quote:

Originally posted by Mustang-PaPa:

quote:

Originally posted by shovelhead:
Check the timing cover for corrosion.

This and is this a closed coolant system or open and are the exhaust manifolds wet?

Open with wet exhaust manifolds.

Probably fell into the motor when he took the intake or heads off. My guess out of the water passages in the intake manifold, and right into the valley of the engine and right through the oil drain holes. BUT, the exhaust manifolds are supposed to be changed every 5 years in salt water and a lot of people don't. Then they rupture and start leaking sea water and iron bits into the open exhaust valves and into cylinders.....sometimes people catch it early enough that they're not buying an entire motor.

Don't rebuild a raw water cooled engine, replace it.

This message has been edited. Last edited by: jimmy123x,

The lifter valley on this engine has few open areas that would allow debris from disassembly to fall into the engine unnoticed. If it fell there it would be there. I pulled the lifters and there was nothing on any of them.

51 year old engine, how many times previously has someone been inside of it? We all know that some "technicians", term used loosely could have done some questionable work in the pursuit of flat rate.

quote:

Originally posted by shovelhead:
51 year old engine, how many times previously has someone been inside of it? We all know that some "technicians", term used loosely could have done some questionable work in the pursuit of flat rate.

Engine shows no sign of ever being out or apart. That's what the owner believes, and pulling it with him and taking it apart, I see nothing to indicate otherwise.

Post a pic up and good luck! Always loved the Sweet 16, though not a boat for where I grew up and live now. I was always amazed when I would see one across Biscayne Bay and running in the chop - literally flying. But as a lake boat and a teenage dream, this was up there with the Countach.

If this has been fresh water its whole life, even raw water cooled block may be OK. I’m with Jimmy though, if possible a new block for all the work you will put in rebuilding. The outdrive was/is the more problematic part of that setup. Hope you get some pics of it back on the water!

quote:

Originally posted by pbslinger:

quote:

Originally posted by shovelhead:
51 year old engine, how many times previously has someone been inside of it? We all know that some "technicians", term used loosely could have done some questionable work in the pursuit of flat rate.

Engine shows no sign of ever being out or apart. That's what the owner believes, and pulling it with him and taking it apart, I see nothing to indicate otherwise.

Unless it has extremely low hours and was babied, I highly doubt that the motor was never apart. The only other way, if there's no water in the oil, is the motor (and boat) sat for a REALLY long time outside in a humid environment without being run, like years, and the motor got internal rust inside and someone got it running again and the chunks just fell off with use. Those boats by nature are driven hard and put away wet by their owners. By the time you have the block (and heads) hot tanked, you'll find that there's nothing left of the block in the water passages. Just buy a new marine crate motor and bolt it in. Also with the newer motors you have to go with longer exhaust risers, or could suck saltwater back into the motor at idle through the exhaust with the newer camshafts in those boats due to how short the exhaust hose is and the flaps.

The Donzi's look a lot better than they run. I used to own a 18' Classic (Testerossa model that they only built 38 of) and put a 350 vortech in it. Mine had been through 3 motors with the previous owner by the time I bought it and the boat was a 1988 and I bought it in the late 90's and sold it to a buddy who is guess what, on his second motor. It did 74 mph. Anyways, it was a handful and never rode right. from 20-55 mph it was either porposing or chine walking or usually both and a handful and you were constantly trimming the drive and trim tabs to try to get that out of the ride, which by the time you do, it's time to slow down again LOL. Once you got over 50 or 55 it would then run flat and stable. I heard the 22' rides good.

Boats 51 years old, it's likely that engine was apart for something in that time frame. Without full documentation or being the owner from day one, nobody can say for sure.

There are only a few ways water gets to an oil pan has to be one of those mentioned or it wasn't run much, left stored or run for short periods and not allowed to burn off any condensation in the oil.

They tell you if you are going to start an engine you need to run/drive it some to burn off any condensation. You don't just take a car, go out start it and let it idle for a few minutes and then turn it off.