455 olds motor from car work in boat

sny97321

Cadet
Joined
Mar 24, 2014
Messages
11
I have a 73 gastron carlson cv-19 jet boat. After taking the motor out for a rebuild I found a cylinder cracked real badly. my question is can I use a 455 oldsmobile engine from a car and just swap the heads and other parts to the new motor or do I have to find a marine engine thanks jim
 

projectcop

Seaman Apprentice
Joined
Aug 14, 2011
Messages
38
Re: 455 olds motor from car work in boat

Hello;
Well you have 2 choices here.
1. Yes; they are the same, but you should at least disassemble the motor and put it back together utilizing a marine gasket set.
2. Find your nearest machine shop and ask them if they can "sleeve" the cracked cylinder in your existing block. When done correctly, this type of repair is at least as strong as the original cylinder wall.
 

Walt T

Lieutenant
Joined
Mar 16, 2002
Messages
1,369
Re: 455 olds motor from car work in boat

I would not re-sleeve. The block is junk. The car 455 is fine and as the man says take it apart, check it out, re gasket it and install it. I love those old Carlsons. These jet boats are loads of fun to goose to 5000 rpms and a sleeved motor isnt made for that. Cheaper to use the car motor anyway.
 

Bob_VT

Moderator & Unofficial iBoats Historian
Staff member
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May 19, 2001
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26,019
Re: 455 olds motor from car work in boat

I have a 73 gastron carlson cv-19 jet boat. After taking the motor out for a rebuild I found a cylinder cracked real badly. my question is can I use a 455 oldsmobile engine from a car and just swap the heads and other parts to the new motor or do I have to find a marine engine thanks jim

If you are going to use a salvage yard motor you are going to want the camshaft (or match the camshaft) from your current motor. Freeze plugs should be changed and all of the "marine" electrics and fuel pump should migrate to the new block.

The blocks are essentially the same just the marine parts are different.
 

MikDee

Banned
Joined
Jun 6, 2007
Messages
4,745
Re: 455 olds motor from car work in boat

The 455 Olds motor, has the biggest bore as opposed to the smallest stroke of all the GM engines, it likes to rev freely. That's why it is suited best for a jet boat.
 

Lone Duck

Master Chief Petty Officer
Joined
Oct 17, 2007
Messages
868
Re: 455 olds motor from car work in boat

the 455 olds motor, has the biggest bore as opposed to the smallest stroke of all the gm engines, it likes to rev freely. That's why it is suited best for a jet boat.
yup!!
 

sny97321

Cadet
Joined
Mar 24, 2014
Messages
11
Re: 455 olds motor from car work in boat

thank you. as luck would have it I found someone who has a buick 455 motor that has been machined with all the parts there but it needs to be assembled and I need to get the bearings and the gaskets for it. Do i need to use the old heads because of how the risers bolt on. what is the difference between a marine gasket set and a standard set. thanks again for the replies
 

MikDee

Banned
Joined
Jun 6, 2007
Messages
4,745
Re: 455 olds motor from car work in boat

The Buick engines have the longest stroke of all the GM motors, basicly a torque, not an RPM motor. Pontiac, & Chevrolet, rank between the Olds, & Buick, stroke wise. Good luck trying to find marine parts for a Buick engine.
 

harleyman1975

Ensign
Joined
May 12, 2003
Messages
959
Re: 455 olds motor from car work in boat

Yea the buick is not the same as the olds motor...don't do it!
 
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