Thread: 350 marine block

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an aquaintance of mine is wanting to build up a 350 chevy motor for his car, except it is a marine block. is there any difference in this block compared to a standard car 350 that will make this a bad choice for a car?

Don is useing one in his bucket . He should know that one .

I once had heard some rotate counter clock wise , i think some Pontiacs did this also ?

No, it is the same. Only difference found is that the dipstick hole was plugged because in th boat application the dipstick goes to the bottom of the pan and becomes a suction tube to withdraw oil. I just drilled out the boss that was there and inserted a regular dipstick tube. As Bob mentioned, some were counterrotating, but now they just do that in the lower unit (run one in reverse).

One thing to watch for is internal corrosion, especially if the engine was run in salt water. I spent a good amount of time with an air hose, shop vac, and water pressure cleaning scale from the water passages of mine, and this was after it was hot tanked at the machine shop.

Otherwise, every part has a GM part number stamped on it, and I was able to use regular bearings, gaskets, etc from a Chevy truck application.

Even when I worked at a Marina, we were never able to determine if the parts like pistons, rods, etc were any different from passenger car parts. Mercruiser and Volvo guard this info like the National Treasure, and would never fess up. However, it seems like these are just passenger car blocks that get brass freeze plugs and head gaskets, and maybe a different cam profile, and are sold to various marinizers.


Hope this helps,


Don

Always use brass freeze plugs anyway. Anyone using steel plugs should have his heads examined.

the rods are X rods some say better then ? but all the pistons crank are not any different. the is cam and brass plugs and not much merc will never give you the answer that why they can screw you down when you need parts all it is a heavy duty 350 that all

thanks for the info guys, it was used in a pump house in wyoming or something to that effect. spent its life on a cradle churning away in a shed.