1977 CVX-20 ( Ford 460 ) Jet Boat. Cracked Block? Heads? Help!

[Elliomcmh]

Hi, last year I acquired a 1977 Glastron CVX-20 Jet Boat with a ford 460 in it. It had been sitting up (covered), for five years before I acquired it. It was winterized before it was stored.


I changed the oil and removed the old gas, installed a new coil and it fired right up. I had the hose hooked up to it and I noticed that it was pouring water out of the block, two freeze plugs had popped out. After reinstalling them, I thought everything was fine, I ran it at idle for a minute or two then checked the oil, I noticed water in the oil.



I just assumed that I had the faucet turned up too high and it pushed water beyond a gasket after I shut the engine off (had that happen on a sea-doo years ago). Pulled the plugs, and there was water in the cylinders too. I removed two or 3 gallons of water/oil mix with my cheap harbor freight pump.


I decided to take it to the river to run it for a few minutes, everything was going great until i noticed the oil pressure at 80psi so I checked the engine and noticed the engine was covered in a oil/water "milkshake". It was coming from the crankcase vent and I could feel a lot of Blow-By even at idle.


I limped back to the boat ramp......When I got home, I pumped approximately 5 gallons of water out of the oil dipstick hole and then at the end, I pumped about a gallon of oil/water mix out of the hole. I then pulled the exhaust manifolds and cleared the water from the cylinders. My harbor freight pump isn't capable of pumping the thick oil sludge out of the cylinder, so there may have been some in there.


I then checked the compression. I have attached a diagram showing the pressure readings as well as a picture showing what came out of the vent. Any ideas as to what is causing this?


Sorry for the extremely long post

 

[Cat nip]

You need to completely tear down the engine. With water in the oil the bearings are most likely shot. When its apart take the block to the machine shop and have them look for a crack in the block or heads. It might be cheaper to get a crate motor. Either way that engine is no good the way it sits. No easy or cheap fix.

 

[Bondo]

It was winterized before it was stored.

Ayuh,..... It was unwinterized, or winterized improperly,.....

Bein' a 460 Ford, yer best bet is to sell off any salvageable parts, 'n buy a runnin' drop in BBC to replace it,.....

Parts for that Ford are rare as hen's teeth, sell the parts to someone tryin' to get one more lap outa theirs,.....

Dependin' on what's salvageable, it might go along ways to payin' for a Chevy,...

The Test, is to isolate the block/ heads from the rest of the plumbin', drain it, 'n pressurize it with air, 'bout 15 psi,....
You'll Hear the leak, follow the sound,....

 

[Cat nip]

Parts are not rare and a good 460 crate engine is about 5grand . If you swap to a chevy motor you would also need an adapter plate for the bell housing and whatever sort of flywheel adapter and new motor mounts that would probably need to be custom made and who knows what else. Its your boat ya do what you think is right, but remember cool ain't cheap or easy. I have been an auto mechanic for 25 years, I have done more than my fair share of engine swaps and fabrication so when I tell you all that I know what im talking about.

 

[jbcurt00]

I completely agree w Bondo. Sell what ya can from the 460 for whatever ya can.

Fords been out of the marine engine business for a long time.

Please post where you can buy a 460 marine crate engine for 5K

 

[Cat nip]

Cant get my phone to make a link for some reason. But powertrain products has a couple stock long blocks for 22 to $2.400 and there is a 460 stroked punched out to somthing like 510 with aluminum heads and states thats its a marine engine for $4.599

 

[Cat nip]

Those are long blocks. I haven't had time to find a fully dressed marine crate motor yet, im at work

 

[Elliomcmh]

I'm going to pull the intake manifold and go from there, I'll keep you posted, thanks!!

 

[Bondo]

I'm going to pull the intake manifold and go from there, I'll keep you posted, thanks!!

Ayuh,.... As soon as ya do that, you can no longer air pressure test it,....

 

[Elliomcmh]

Bondo, what's the best way to pressure test it? I have an air compressor.

 

[Elliomcmh]

And can I pressure test it even if it's a raw water cooling system?

 

[Elliomcmh]

Well it looks like I have a cracked block. Anyone ever removed an engine from one of the Berkeley pumps? Or have any suggestions on where to find a block? I assume this isn't repairable.

 

[Elliomcmh]

No Title

 

[Bondo]

Anyone ever removed an engine from one of the Berkeley pumps? Or have any suggestions on where to find a block? I assume this isn't repairable.

Ayuh,.... I think there's 4 or 6 bolts to free the driveline from the motor,...

Then the plumbin', wirin', 'n the motor mounts,....

A runnin' drop-in Chevy 454 is probably gonna be the easiest, cheapest way out for ya,.....