5.7 Mercuriser Cracked Block

[texans543]

Ahoy Mates,


I have been trolling this form for a while, read a lot of great information.

Here is my issue, New to me 2000 Crownline 180, Know bad motor, very sad….a young guy first boat did not winterize it. It's a 5.7 Mercuriser 4 BBL with the 638 Block. Whoever owned this boat first spent a lot of money and time upgrading this boat to this motor and out drive. Here is my question.


I am looking at replacing the long block, thinking about getting the 880, but have the fear of the weakness in this block on cracking, should I just replace it with a rebuilt 638 block and live with the older age block or move into the 880 block. From my understanding is that I can use everything else from the current motor, just getting a new vintage. Really here are my 3 thoughts.



1. find a use 638 block and have it rebuilt (cheapest Option)

2. Buy a rebuilt motor from Michigan Motorz or someone (most expensive option)

3. find a truck donor block and just change over the cam from the current option (unknow risk option)



And advice on my many issues.

 

[Scott06]

Ahoy Mates,


I have been trolling this form for a while, read a lot of great information.

Here is my issue, New to me 2000 Crownline 180, Know bad motor, very sad….a young guy first boat did not winterize it. It's a 5.7 Mercuriser 4 BBL with the 638 Block. Whoever owned this boat first spent a lot of money and time upgrading this boat to this motor and out drive. Here is my question.


I am looking at replacing the long block, thinking about getting the 880, but have the fear of the weakness in this block on cracking, should I just replace it with a rebuilt 638 block and live with the older age block or move into the 880 block. From my understanding is that I can use everything else from the current motor, just getting a new vintage. Really here are my 3 thoughts.



1. find a use 638 block and have it rebuilt (cheapest Option)

2. Buy a rebuilt motor from Michigan Motorz or someone (most expensive option)

3. find a truck donor block and just change over the cam from the current option (unknow risk option)



And advice on my many issues.

If it were me I would get a new vortec base engine from Michigan Motorz. Thats what I did when I repowered for same reason you are (PO didnt winterize...) Yes it was more money, but I'm now on my 6th summer with absolutley no issues, just beat the snot out of it skiing and wakeboarding...

 

[Nextelbuddy]

if i could go back and do it over again id get a crate setup and be done with it.

i have a recent few threads where im recovering from a blown 5.7. I bought a truck engine from someone and they neglected to tell me it was cracked in 4 places from running water in the block. then i used the vortec heads from that and found another 350 short block and had an engine builder and machine shop put everything together.

i ended up paying twice for work, once on bock that was busted and then once again on the 3rd engine assembly.

all in all i'm siting around 7k for everything, engines, parts, machine work, labor, upgraded parts along the way

you be amazed how many things you dont NEED to change but makes no sense not to do them when you have everything apart.

like the engine coupler, mine was fine but that is a pain in the ass to change when the engine is in (engine has to be removed) so there goes $315 for a mercruiser oem coupler since engine is already out.. things like that add up quickly

 

[Rick Stephens]

if i could go back and do it over again id get a crate setup and be done with it.

i have a recent few threads where im recovering from a blown 5.7. I bought a truck engine from someone and they neglected to tell me it was cracked in 4 places from running water in the block. then i used the vortec heads from that and found another 350 short block and had an engine builder and machine shop put everything together.

i ended up paying twice for work, once on bock that was busted and then once again on the 3rd engine assembly.

all in all i'm siting around 7k for everything, engines, parts, machine work, labor, upgraded parts along the way

you be amazed how many things you dont NEED to change but makes no sense not to do them when you have everything apart.

like the engine coupler, mine was fine but that is a pain in the ass to change when the engine is in (engine has to be removed) so there goes $315 for a mercruiser oem coupler since engine is already out.. things like that add up quickly

Not that your thoughts are wrong, but a coupler with a properly aligned motor will last the life of the boat. I'd find it hard to put $300 in a part I can swap out in an afternoon.

I completely agree with the crate engine path unless you are doing most of the work yourself. Stick it in and go boating!

 

[texans543]

If it were me I would get a new vortec base engine from Michigan Motorz. Thats what I did when I repowered for same reason you are (PO didnt winterize...) Yes it was more money, but I'm now on my 6th summer with absolutley no issues, just beat the snot out of it skiing and wakeboarding...

Scott06 great info. I called them today and they are at a 3 to 4 month lead time!!! I have called many and they all say the same thing. Not I did find a used motor, "same block" for super cheap today, $200 bucks in a running SUV. I think I am going to check that out then take it to get Machined and replace all the internals. Local shop said they can do that for $150 bucks + the parts costs. Thoughts on that?

 

[alldodge]

If your in fresh water change core plugs and then swap everything else from your long block, go boating

 

[Scott06]

If your in fresh water change core plugs and then swap everything else from your long block, go boating

What he said. If its running has good compression and oil pressure put it in and run it.if the truck engine is a vortec and the old one is not you will need a new intake… but vortecs are worth 40 hp

 

[texans543]

Thank you all for the info, I bought the motor last night. It’s in great shape. I am going to do a minor rebuild on it, swap over my 4bbr, and let her eat!

 

[Scott Danforth]

I would just swap core plugs and run it until you need a rebuild