Help, catastrophic failure

[jeffpaff]

I believe I have internal damage to my VP 5.7L GXi 300 J! I was thinking about getting a long block and swap everything over from my current engine. Has anyone done this? Any advice? If I go to a higher HP motor can I still use everything else off the old motor?

Thanks in advance

 

[alldodge]

Many have swapped long blocks and did just fine.

Your original motor is listed as HP at the prop, new and reman motors list HP at the flywheel. So a 330HP long block is really a 300HP at the prop. A motor which has been bored during remanufacture will also gain a few HP

You want a standard rebuild and not a real HP build like going from a 350 to a 383 stroker, or motor with high lift cam and such. Going to a high HP build means your ECM will not work

 

[FunInDuhSun]

I was thinking about getting a long block and swap everything over from my current engine. Has anyone done this? Any advice?

Yes, I had to replace a motor (Crusader 270) on my current boat 9 years ago. In my case it was due to a crack in a cylinder wall. I thought about just replacing the head but the motor already had 800 hours so I went with a remanufactured long block with a 2 year warranty. I was able to re-use most of the ‘stuff’ but remember- all those items are used, so it makes a lot of sense to replace the more critical components while you can. I put on a new engine water pump, spark plugs, hoses, belts, and (of course) new gaskets for the manifolds (intake and exhaust) and carb.
I also made the GREAT decision to have a mechanic set up and test run the ‘new’ motor on his bench to assure everything was working correctly and wasn’t leaking fluids. My agreement was that he would test it with me present so I could personally confirm proper operation. We ran it for about 20 minutes at various speeds and at idle. I was so satisfied with the job that I had him install it in the boat.

 

[Scott Danforth]

motor swaps are done all the time. there is nothing special about swapping a motor.

pull drive, disconnect motor, pull motor....... transfer parts, test run on pallet, install motor, align motor, install drive...go boating

you have a fuel injected motor, so unless you re-flash your ECM, replace what you have with exactly the same dont think about more power, less power, etc. replace with exactly the same.

assuming you R&R the motor your self,,,,

to rebuild your motor, work with your local machine shop. unless you punched a rod thru the block, you are looking at about $1500-$1800

to build a new motor from parts, you will spend about $3000-$3300, then swap all your parts over

to buy a new long-block you will spend $3100-$3300, then buy exhaust gaskets and swap all your parts over

to buy a complete new bobtail, you will spend about $14k

 

[Scott06]

I did the same thing a couple years back. Would recommend just getting a new base engine vs reman unless you have a machine shop you have a history with. For $3 K you get the same Engine VP buys from GM. Would also recommend you look at rear motor mounts and engine coupler while it’s out. Check you exhaust condition as well and replace as needed

I swapped over everything off the old engine and ran it on a pallet in driveway before installing.

 

[BRICH1260]

I had to replace my 5.7 gxi-j last year. I went with a new Michiganmotorz long block and just transferred my original components over.