[Chris B]

Happy New Year to all.

Brought the Z260 to the shop with water in the oil. Shop called today, said block is cracked and he can install new long block for $9,000.00. Think I will go get it and try to do something myself. I am a pretty good shade tree mechanic, so thinking of finding another engine maybe a rebuild and fixing it myself. There is no way I can spend that kind of money on this boat. Any thoughts?

[Hudson River Steve]

Hi Chris,
Your shop was quoting you a NEW 7.4L long block which do tend to be pricey. You can certainly find a Reman 7.4L and install it yourself for much less than half of what you were quoted. You will probably have to pay the core charge since your block cannot be rebuilt (usually less than $500). Good luck.

[ShabahZ280]

Wow, just what you wanted to hear, right?!? Hudson River Steve's right, you can get into a remanufactured/rebuilt 7.4L for less than half. You can likely find a used replacement online, many of the offshore guys swap these engines out of their boats with regularity. A couple places you could look would be offshoreonly.com in their classified section. Check out all the major boating forums, engine rebuilders like michiganmotorz, and even ebay has some deals too. Keep us updated on this project!

[Chris B]

Thanks for the feed back guys. Picked up the Z-260 from shop yesterday. Will look for a replacement engine, so far recommendations from the mechanic and some boat guys in the are are for a later model 496. My son was into go fast boats for a while in the New Orleans area (27' Fountain with 502 Alpha 1) so he is checking his old contacts to see what may be out there. The way the mechanic determined the block was cracked is that he performed a compression test, which found that all cylinders are between 170 and 180, ruled out head gasket or cracked head. He drained the manifolds which were full of water. When he tried to drain the block it had no water in it so he said that indicated a busted block. Before I pull the engine, going to remove and pressure test the oil cooler (shot in the dark). After that will pull engine and while waiting to locate another engine will tear into this one to see if I can actually find the crack.

[Motoxxx43]

I like the idea of the 496. That thought is in the back of my mind if/when this 7.4 of mine needs replaced. Like Shabah was saying, those other forums have a lot of stuff in the classified sections. Sure would be nice to stumble on a 496 mag HO...

[Motoxxx43]

May want to give this place a call. I hear they are legit.Unclaimed GM Engines from 2014

[Chris B]

Thanks Motoxxx43 for the info. I looked them up on the internet and they have a bunch of engines and look like a reputable place. This weekend was nice so decided to try to pressure test the cooling system and engine. I disconnected the raw water hose from the thermostat housing and rigged a fitting to pump air into the system. Blocked off the hoses to the manifolds and water heater. Applied 20 PSI air pressure and gauge held steady with no pressure drop. Increased to 40 PSI and had same result. Pushed it to 60 PSI and the system including the heads and block held the pressure until the gasket on the back of the circulating pump blew. This test did not include the oil cooler. So far no leak. Removed the circulating pump along with the oil cooler and tested the oil cooler. The oil cooler tested fine. So if there is a crack in the block it did not leak during the pressure test. I did discover that the block was full of water when I removed the pump, so much for the mechanic that claims he tried to drain the block and it had no water in it which indicated that the block was cracked. Have the circulating pump fixed and will put it back on first chance I get. Will change the oil and run the engine to see what happens. May pressure test again after engine is warm just in case what ever put water in the oil did not open up and leak while engine was cold.

[rainman55343]

Wow I only paid 3800 for my 5.7 engine. Think that is way too high.