cracked block......

[kdgncop]

I've got an '85 bayliner capri 1950 with the 5.0 in it. I have winterized it 4 times now and last fall when I did it we were getting ready to move so I stuck the bottom two plugs back in and forgot to take em back out. started up just fine the other night with the exception of water POURING out the side of the block. It wasn't an expensive boat and I don't want to spend a ton on it. do I have any options other than a new block??? my neighbor said to try JB weld on it. He said he had done it on an old tractor he had and it lasted forever. Is there much pressure on the cooling system side of things??? He mentioned to grind it out, put a bit of the fast set in, press in a strip of pantyhose and let dry. then follow up with another layer that is fanned out twice as wide.

Think this will work????????? i figure i need a new block anyway....

any leads on where to find a block to transplant everything into???

 

[Coors]

Re: cracked block......

Jasper

 

[whywhyzed]

Re: cracked block......

I wouldn't JB a 305 Chevy. I'd bet there's over 1 million 305 blocks in US wrecking yards.

 

[John_S]

Re: cracked block......

"I'd bet there's over 1 million 305 blocks in US wrecking yards."

yep, because it will cost the same or more to rebuild the 305 than to go to a 350.

 

[kdgncop]

Re: cracked block......

Can I just have the shop use a regular automotive block?? What about the lower drains on the block??

 

[Haut Medoc]

Re: cracked block......

I would try to JB it if you have no water in your oil.....
Have you determined exactly where it is leaking from?.....
An auto engine will not work for you, the cam will be wrong......​

 

[Windykid]

Re: cracked block......

Have you checked to see if you just blew a freeze plug out?

 

[whywhyzed]

Re: cracked block......

Can I just have the shop use a regular automotive block?? What about the lower drains on the block??

Yep, the marine block IS an automotive block and you'll find threaded plugs in the exact same locations on any car/truck 305

 

[Windykid]

Re: cracked block......

If I am not mistaken, most marine blocks are 4-bolt main and loaded with brass freeze plugs. You could replace all freeze plugs on an automotive block. Dont think there would be a difference in performance except the cam shaft should be changed.

Someone will chime in who knows this stuff better.

 

[Coors]

Re: cracked block......

2 bolt.

 

[riverjet502]

Re: cracked block......

A engine block is an engine block. It doesn't care if it is going down the road or across the water. The biggest difference between a marine engine and a car engine is the "clearance's on the bearings, and piston bore" A marine engine will generally be set up a tad looser then a car engine. example instead of 1-1/2- 2-1/2 thousands maybe more like 2-1/2 -3 thousands. This is due to the cooler running temps of a marine engine and the fact that the block doesn't heat up evenly like a car engine does. The expansion rate is different because your not using a raditator to help keep your cooling temps constant. A 2 bolt will work just fine. Due to the fact that a stock 305 isn't stressing the block with wild hp numbers or gobbs of torque. It is important to run a quality marine cam tho for your application. If not you do run the risk of exhaust reverberation (sucking water back up through the exhaust). This will hydrolicly lock the motor and very likely will bend rods... If it was me I would pull the tiny mouse motor out and swap for a healthy 350.... Good Luck.....