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Old 02-28-2011, 09:10 AM   #11
curtis73
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Re: marine engines in street cars??????/

I think you'll find that marine cams and stock street cams are nearly identical these days. Marine engines have a greater need for flat torque curves and being NOT peaky than a street engine, so they use some pretty recognizable numbers.

For instance, I have a stock Melling Mercruiser grind for a 350 that specs out to 194/204 duration on a 114 LSA. Nothing fancy about it, just a normal stock grind. Worked great in my station wagon, but ran out of breath at 5000.

In actuality, most marine engines these days are carbon-copies of what gets put in the street version. They add the brass freeze plugs, a bronzed lining in any aluminum water passage, a marine water pump, and mechanically speaking - that's pretty much it. It used to be that they ran larger bearing tolerances requiring 20w50 oil, but metallurgy has come so far in the last 30 years that they can use stock street tolerances and just use 10w30. The Marine Vortec 350 I have torn apart in my garage has a stock cast crank, two bolt mains, and the block and head castings are 880 and 062 respectively - straight off the street and into a boat.

The main concern with running a marine engine on the street comes if the boat was ever used in salt water with an open cooling system. If it ever circulated salt water, the salt will stay in the porous block casting forever. There is no way to wash it out. The problem is, salt and ethylene glycol coolant don't play well together. They can make some fun green jello.
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