Mercruiser 454 I Need Help Identifying This Engine

[jws123]

Well I am back! I bought a speed boat its been a few years since I have owned a boat. The 454 engine in this boat is shot It had water in the oil. I tried to save it but it was bored out to many times and was just all wrong.

I have a spare Merc 454 Mag out of a boat that had a bravo 3 drive that I have had sitting on a shelf for 5 years. I tore it down today It looks like I can save it I did find that it has roller lifters I guess thats good?. My question is I forget how to find out what year this engine is so I can order new rings ect. I no longer have any marine stores they all closed so I have no one to ask ahah. I am basically doing a backyard rebuild and need to freshen it up The serial number Is F088 10237297 Any help would be appreciated.

 

[jws123]

I also found 10232427 stamped on the top of the pistons I have no knowledge of this engine if it was ever built ect.

 

[alldodge]

Look below the distributor on the block deck for the casting number

Then see if the number comes up in this link
https://www.mortec.com/bbc.htm

 

[Scott Danforth]

Only way to determine if the motor was rebuilt is to pull it apart and inspect it

Measure the bore diameter, the crank journals, etc

Post your casting numbers. The 454 mag is a rectangular port motor where most of the 454s were oval port

 

[jws123]

 

[jws123]

Here are some pictures yes i know its dirty its getting dunked once its taken apart.

 

[Scott Danforth]

Stock L29. 330 hp

10237297...454.......96-up...4-bolt, Vortec 7400", "L-29" Gen.VI

Oval port

10114156...91-up...oval...OPEN...Gen.V & VI 454, 118cc chamber

 

[jws123]

Thanks for the information!! I have one other dumb question that im confused about. This is the engine In the boat its seized and scrap It had a brand spakin new intake on it. Can I re use it? the intake shape looks diffrent compared the the ones posed above they are more of the oval shape but the ones I posed above appear more of a circle?

 

[Scott Danforth]

The intake has to match the heads. As stated prior, your magnum has rectangular ports and needs a rectangular port intake

The motor in the pictures is a mix of Gen 5 oval port heads on a Gen 6 block

Before staying the motor is seized, pull the drive. Because if the drive is seized, the motor won't turn

 

[jws123]

The intake has to match the heads. As stated prior, your magnum has rectangular ports and needs a rectangular port intake

The motor in the pictures is a mix of Gen 5 oval port heads on a Gen 6 block

Before staying the motor is seized, pull the drive. Because if the drive is seized, the motor won't turn

The drive is already removed does anyone know a good place to get short blocks? The engine i was going to use after honing the cylinders today they didnt turn out good enough. I dont have any machine shops local anymore and I know jasper ect is crap now.

 

[Scott06]

The drive is already removed does anyone know a good place to get short blocks? The engine i was going to use after honing the cylinders today they didnt turn out good enough. I dont have any machine shops local anymore and I know jasper ect is crap now.

Try michigan motorz they do reman engines not sure if they offer short blocks but they have long blocks

 

[Scott Danforth]

You can't just dingleberry hone cylinders. You need to bore the block, then hone it.

Not sure where you are at, but there should be a good machine shop within an hour or two

 

[jws123]

You can't just dingleberry hone cylinders. You need to bore the block, then hone it.

Not sure where you are at, but there should be a good machine shop within an hour or two

Im from Nj almost all machine shops have closed or are shady as fk. I was trying to hone the cylinders to get some surface rust out of them found pitting so yea it needs to be bored.

 

[Scott Danforth]

There are about a dozen great machine shops in New Jersey

LRB is one D&F, Olsen Engines, or Chucks Automotive come to mind

 

[jws123]

There are about a dozen great machine shops in New Jersey

LRB is one D&F, Olsen Engines, or Chucks Automotive come to mind

Olsen Engines is closed. I will look into the others thanks.
I did message one a few days ago but have heard nothing back.

 

[jws123]

Evidently 454 marine engines are suddenly hard to get and 10x over priced for whatever reason right now. People want 5k for a used engine.... I even tried to find a car engine to convert but everyone is off their rocker on the prices... found nothing worth while under 1600 I put the boat up for sale for now . Both engines I have are NG couldnt save them unfortunately the one in the boat has a cracked block. The other one I have I would need to have the cylinders redone they did not clean up. Could not find a machine shop near me that cared enough to do the job. Its crazy tho these engines use to be very easy to get just cant justify 4-5k for a used engine knowhing nothing about it.

 

[Scott Danforth]

Remaned Big Block engines from Michigan Motorz are $6k

Everything has gotten expensive in the past 7 years

Just a core motor these days is $700+

 

[jws123]

Remaned Big Block engines from Michigan Motorz are $6k

Everything has gotten expensive in the past 7 years

Just a core motor these days is $700+

yea its crazy even just 2-3 years ago i could get a used 454 marine for like $1500. I will keep looking until the boat sells found a few engines but the whole boat comes with it ahaha dont have time to cut a boat up.

 

[tpenfield]

What Scott said . . .

7.4L Gen 6 . . . oval ports . . . 330 ish HP. I had twin versions of those . . . 1996 vintage.