ATV Florida Forum

General => Open Discussion => Topic started by: bocephus300 on April 01, 2008, 07:49:20 PM



Title: boat engines
Post by: bocephus300 on April 01, 2008, 07:49:20 PM
i have a nice little speed boat it has a inboard 454 in it. anyways i kinda threw a rod thru the oil pan. so i need to get a new engine. whats the difference between an automotive and marine? i know the heads are different and the cooling system. can i get a short block 454 and just swap heads? or sholud i just bend over and buy a marine spec 454?


Title: Re: boat engines
Post by: Thunderdually on April 01, 2008, 09:31:38 PM
I put a non marine 350 chevy in my boat. About the only difference is a marine engine has brass freeze plugs stainless steel head gaskets, stainless steel water pump for the block. So I changed all that out. The marine fuel pumps and starters are different also.some say the pistons are different but I'm not sure on that.


Title: Re: boat engines
Post by: bocephus300 on April 01, 2008, 09:36:56 PM
i have my whole old eng. i can strip all the goods off it. but thanks for the reply relaay helped


Title: Re: boat engines
Post by: exrider on April 02, 2008, 07:00:37 PM
I put a non marine 350 chevy in my boat. About the only difference is a marine engine has brass freeze plugs stainless steel head gaskets, stainless steel water pump for the block. So I changed all that out. The marine fuel pumps and starters are different also.some say the pistons are different but I'm not sure on that.

You are correct Sir. But don't forget the cam.


Title: Re: boat engines
Post by: Sleazy_Rider78 on April 02, 2008, 11:16:19 PM
Bocephus,

I will give one of my buddies a call and see if he can help salvage or rebuild your engine.  He has fixed several blown engines from cars to boat engines and won't take advantage of you.  I will give him a call this weekend and see if he can help.  By the way, what kind of engine is it?  If my buddy can't help you I also know a good marine shop in hollywood called Van's Marine, I believe the owner's name is George, he's an honest guy as well and have had him fix a couple of outboards for me.  Not sure if he works on inboard engines but Van's Marine number is 954-922-4619.


Title: Re: boat engines
Post by: gery350 on April 03, 2008, 08:55:22 AM
the cam is different as well on a marine engine. if you dont use a marine cam you have a high risk of sucking water back in thru your exhaust and getting it into the compression chamber.


Title: Re: boat engines
Post by: Chevy1500z71 on April 03, 2008, 09:33:04 AM
marine engines normaly just have more balls. infact the biggest upgrade on a truck like mine but the 96-98 multi port model is to upgrade to the marine intake.

and you realy shoudlnt have trouble rebuilding what you have, i dont see a need for an entire new engine. if you ask me its the perfect excuse to stroke it out... but thats just me


Title: Re: boat engines
Post by: big-daddy on April 03, 2008, 10:14:27 AM
OK here a question for you, is it a single boat?

 If it has two engines, one rotates the other way ;)


As far as the cams goes........ I been using race cams on boat for a long time without any problem. The exhuast system we uses the water only too cool the exhaust system and doesnt mix into the exhaust, runs on the outside of the manifolds out the back of the boat.


Title: Re: boat engines
Post by: garym on April 03, 2008, 08:32:16 PM
BE CAREFUL of the electrical (alternator etc...)marine ones are sealed so no sparks can be exposed to potential gas fumes in the motor compartment...also the windings in a car part will not last in a marine enviroment...too much humidity and think of the salt mist on stuff...in other words, put some salt water on you car motor and see if it starts in a few days....get my point?


Title: Re: boat engines
Post by: bocephus300 on April 03, 2008, 09:42:37 PM
wow thanks for all the responces i gotta pull the engine this weekend and figure what all broke. the engine was new er it was completely rebuilt like a year ago and we ran it maybe twice. pulled it outta the water to get repainted. i started that thing like every week. till one day it did not fire right up. so i figure weird i pulled the first plug wire to check for spark, it sparked good. so i put it back on, like 15 and tried to start it again it cranked over a few times and backfired so bad it blew off the breathers and carband thats when i heard the worst noise ever... the sound of the oil pooring out the bottom. i have only visually inspected it. i can see the bottom of the a connecting rod sitcking out the oil pan. the thing is that its the rod and the cap. which leads me to believe the crank is prob broke off.  any way my buddy is going to help me out he is a marine mechanic (so thanks very much sleezy rider but hold off on your friend, i might need him to do the machine work for it but not to sure yet) hopefully its not to bad. getting a stroker setup for my 454 would be nice.


Title: Re: boat engines
Post by: exrider on April 05, 2008, 04:01:22 PM
OK here a question for you, is it a single boat?

 If it has two engines, one rotates the other way ;)


As far as the cams goes........ I been using race cams on boat for a long time without any problem. The exhuast system we uses the water only too cool the exhaust system and doesnt mix into the exhaust, runs on the outside of the manifolds out the back of the boat.

No one has made a counter engine in at least 20 years. It is all done in the drive.