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