Carver Owners Forum

Well, the good news is, we just bought a 2000 350 Mariner with only 300 hrs on port engine and 100 on starboard. Bad news is 300 hrs is all the port had left! 4 miles into the trip to bring it home, it threw a rod thru the block. Needless to say, we are beside ourselves, but the reality is, we need a complete engine replacement of an engine that is no longer made. Any ideas or knowledge with online engine companies that sell long blocks or complete reman engines? I need all the help I can get.
Thanks in advance,
Skip Williams
Charleston, SC area

7.4 liter or 454 cubic inch gm motors are still made and readily available. They don't give them away but you will find many options. Just to a search for 7.4 marine long block.

You may want to look at the other motor also. These should provide 1000 hours or more if properly maintained and not pushed to the limit all the time. Check the oil, etc. Possibly lack of maintenance or water intrusion?

https://www.perfprotech.com/new-gm-454- ... uct/242826

just one option....

Google search, u will find rebuilds for a lot less.

GM stopped making 7.4L blocks a while ago but they are still a dime a dozen. Anything "New" will be new old stock. Make sure you get the same generation/build/spec so you have a balanced pair/output.

Find out what caused the failure. If it was due to an OEM defect, contact Volvo. They may help through good will.

What is the serial number of the block that failed?

Viper, I am pretty certain GM still casts 454 and 502 blocks for aftermarket applications such as marine / truck replacement and car building.
When they stop making blocks, you will see a core charge for rebuilds.

Thanks, everybody, so far. I should have been a little more clear in my first post. Yes, I knew they are still made by 3rd parties, but they are not available thru Volvo any longer. Not only that, (according to the local Volvo dealer) the 7.4 was discontinued for the 8.1 and they also no longer have the 8.1 available. Not that I would have gone with the 8.1, due to the 2 engines not matching, but I just don't know which 3rd party to trust, as far as making a good product. A local mechanic said he uses Michigan Motorz.com. Their price is $5599 + shipping and + $500 core charge. He would then charge $2000 for the labor, so I'm looking at $8500, once the dust settles.

Viper wrote:Source of the post GM stopped making 7.4L blocks a while ago but they are still a dime a dozen. Anything "New" will be new old stock. Make sure you get the same generation/build/spec so you have a balanced pair/output.

Find out what caused the failure. If it was due to an OEM defect, contact Volvo. They may help through good will.

What is the serial number of the block that failed?

The serial number is unknown (suspicious sounding, huh?) During the survey, the surveyor did not find the tag and put down "Unknown". Monday, I was digging thru all the paperwork that was left on the boat and discovered what I THINK is the serial number for the PREVIOUS engine, before this one was replaced in 2008. It is 4012022461-3860936. Have no idea if that is for the current engine. Local Volvo dealer said that one was never registered with Volvo.

You don't need to use a Volvo block. They buy them from GM and marinize them. All of your Volvo gear will "bolt" on to the new or remanufactured long block. You do want to make certain you use the same series long block. Yours should be the Vortec roller motors, unless someone cheaped out when they last replaced them.
The serial number will tell.

tomschauer wrote:Source of the post You don't need to use a Volvo block. They buy them from GM and marinize them. All of your Volvo gear will "bolt" on to the new or remanufactured long block. You do want to make certain you use the same series long block. Yours should be the Vortec roller motors, unless someone cheaped out when they last replaced them.
The serial number will tell.

Any idea where to find a serial number, if the tag on the side is no longer legible? I cannot trust the documentation on board, at this point!