Sea ray sundancer motor ?

[ericcarr]

Alright, I have a 1990 Siri Sundancer that I will be putting a new motor in this next spring. I have the chance to get a 1970s 454 Motor that is mildly build. I guess my question is will the 70s motor bought into my 90 Sundancer without any modifications. Give me your input

 

[GA_Boater]

Input - You need to tell us more. All Mercruiser motors are not the same.

What's in it now - Serial number and the serial number of the 70's 454.

 

[Scott Danforth]

by "mildly built" what exactly are you referring to. if it was "mildly built" for a boat is one thing. however if it was "mildly built" for a car, no luck charley as it will have the wrong pistons (wrong compression ratio) and wrong cam (wrong duration) for a boat.

if your Sea Ray has a MK IV motor, then it is the same vintage. however if your SeaRay has a Gen V motor, then some things wont work. post the casting number of the blocks.

while the MK IV block was the same from 1965-1990 there were at least 6 different heads used, about 4 different cams, and about 4 different pistons over the years.

the accessory drives, intake manifold, exhaust manifold, etc changed every few years.

 

[ericcarr]

Well nothing is in it now, I pulled it last year and parted it out..I’m just trying to get her back on the water as cheaply as I can.
All I know is the motor is out of a 70’s car and is mildly built

 

[Scott Danforth]

All I know is the motor is out of a 70’s car and is mildly built

not going to work in a boat. I can almost guarantee that the compression ratio is too high and the cam in there would cause too much reversion. Not to mention you have to pull it apart anyway to change the head gaskets, core plugs and water pump or you need to run a heat exchanger

you would be much farther ahead to build a motor from a salvage yard core and build it as a marine motor

 

[Bondo]

Well nothing is in it now, I pulled it last year and parted it out..I’m just trying to get her back on the water as cheaply as I can.

Ayuh,..... So what was in there,..??

What do you have left to work with,..??

Is the drive still there,..?? What is it,..??

 

[Bt Doctur]

and if it came with an Alpha your limited to 300hp and thats with a gentle right hand

 

[ericcarr]

Ok well it had a 330 hp motir innget with a bravo 1 drive. I put a bravo 3 drive on it just before I decided to pull the motor for inspection, had a bad motor...

 

[Bondo]

I put a bravo 3 drive on it just before I decided to pull the motor for inspection, had a bad motor...
I pulled it last year and parted it out..

Ayuh,...... So you need a fully dressed, turn-key bobtail motor,..??

A car motor, "mildly build." doesn't get you where you need to be,......

 

[ericcarr]

All I really need is a long block...heads & block with internals

 

[QBhoy]

All I really need is a long block...heads & block with internals

Hi there friend.

best advice I can give you....is listen to what these guys above are telling you. You’re very fortunate that these 4 guys in particular (there are a few more with similar unrivalled know how who might add to things) have decided to help out. They don’t come much better than these guys on subjects like this. If I was you, I’d bug them and ask them everything and anything about what you are trying to do here, while you can. Trust me on this one. Take and write down all they have to say about it. You aren’t the first to ask advice on this very subject and won’t be the last. It’s a common question. It always ends up the same way. These guys are correct. They’ve been there, done it and bought the t shirt, haha.

good luck !

 

[ericcarr]

Ok, what if I can get a stock auto motor & put in her?

 

[Bt Doctur]

put a 6.2 in it same hp, smaller block

 

[Scott Danforth]

Ok, what if I can get a stock auto motor & put in her?

You need to post the block casting number so we know what was in there first

 

[ericcarr]

 

[Scott Danforth]

what ever you posted didnt show up

 

[ericcarr]

[No message]

 

[ericcarr]

Sorry about that second pic...

 

[Scott Danforth]

block casting, on flywheel housing embossment behind the starboard cylinder head. not the serial number on a sticker on the spark arrestor.

 

[Scott Danforth]

mainly because your serial number comes back as [h=1]7.4L BRAVO GM 454 V-8 1988-1991 - 0B771113 THRU 0D603117[/h] which could be a 1965-1990 Mark IV or a 1990-1995 Gen V

which is why you need the block casting number