350 to 454 possible?

[michaelrj9]

Hi all
Idon't know if I should of posted this here or in the bayliner forum but here it goes

I have a 1987 bayliner contessea 28' with a chevy 350

Is it possible to put in the chevy 454 in it?
What would have to be changed out?

I know motor mounts,intake & exhaust manifolds,risers,water pump etc...


How about the outdrive?
What would have to be done with the out drive?

what else would need to be done?

how many mph should I see different?

Any way to just improve the 350 to get more mph?
Right now the 350 is just stock.


Thanks everyone

Michael

 

[Bondo]

Re: 350 to 454 possible?

Hi all
How about the outdrive?
What would have to be done with the out drive?

Just What Outdrive are we talking about Mike,...??.....

 

[DHPMARINE]

Re: 350 to 454 possible?

I'd like to see your boat with at least a PAIR of 4.3 V6's. V8's better.
28 feet is a lot of hull to move,and a Bayliner tends to be a large boat,at that length.
The 454 will be an improvement,but you should have a Bravo drive to go with it.That means a new transom housing inside and out.And more.
Unless cost is no option,maybe trade in this boat for what you really want.IT is 20 years old.

DHP

 

[whywhyzed]

Re: 350 to 454 possible?

Is the Contessa a planing hull?

 

[Don S]

Re: 350 to 454 possible?

Yes, the Contessa's are a planing hull, usually powered with a Volvo 260 engine with a 280 outdrive.
I would forget the 454 if it was me, too much changing.
A fairly easy upgrade to start would be to change the lower unit on the drive to a DP.
I have a 27 Bayliner that I did that to and it went from a 24 mph boat to a 30 mph boat at WOT. cruise is better and a lot better milage.
If you still want more speed, look into a new 350 MPI engine. It'll take some adapting for the exhaust, which is fairly easy, although expensive. You would also need a different bellhousing for the larger flywheel.
BUt anyway you look at it, it's still easier and cheaper to install and run than a Big Block.

 

[michaelrj9]

Re: 350 to 454 possible?

Yes, the Contessa's are a planing hull, usually powered with a Volvo 260 engine with a 280 outdrive.
I would forget the 454 if it was me, too much changing.
A fairly easy upgrade to start would be to change the lower unit on the drive to a DP.
I have a 27 Bayliner that I did that to and it went from a 24 mph boat to a 30 mph boat at WOT. cruise is better and a lot better milage.
If you still want more speed, look into a new 350 MPI engine. It'll take some adapting for the exhaust, which is fairly easy, although expensive. You would also need a different bellhousing for the larger flywheel.
BUt anyway you look at it, it's still easier and cheaper to install and run than a Big Block.

Hi, Is your 27' a 10' beam?
I have the 350 chevy with a omc cobra outdrive.
Could I still change the lower unit to dp or something equivalent to get the jump in mph?

Hitting close to 30 would be great.

Right now it does not even plane.

I know it needs a tune up as it spitts or sputters once in a while. Hopefully nothing major wrong with the engine except just a tune up. maybe it will get up to plane with a tune up.

Michael

 

[lilmandavis]

Re: 350 to 454 possible?

ill trade you my contessa with the 460 in it it will surley plane out! goes about 35 wot id be happy with only a 350. as far as i go i just fill it up with people and we cruise around dont need to go fast with a party on board.

 

[lilmandavis]

Re: 350 to 454 possible?

heres mine http://i78.photobucket.com/albums/j91/joshuaj_33909/almostthere.jpg

and the engine http://i78.photobucket.com/albums/j91/joshuaj_33909/100_30341.jpg
of course the oil cooler is hooked back up in the boat. i broke it in before i hooked that up cause its a pain to get all the break in oil out of the cooler while its in the boat.

 

[Gary H NC]

Re: 350 to 454 possible?

Nice looking boat lilman!!

 

[lilmandavis]

Re: 350 to 454 possible?

completly redoin everything from the hull up!!! thanks all new floor gas tank carpet interior. everything custom. work in progress. not a bad boat for a 25 year old a? (me, the boats only what 20?!)