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Originally Posted by Budman II
(Post 3732811)
That is the exhaust heat riser passage. It takes some of the hot exhaust and circulates it under the intake to warm the charge for cold weather operation. It can be useful on a car, but not needed in a boat. If you look at your gaskets, you should see a metal blockoff plate to keep the exhaust from circulating.
It could be as simple as an intake manifold gasket leak, but the heads should be closely checked, along with the intake manifold and exhaust manifolds / risers. If those risers are more than 4 years old running in salt water, they should probably be replaced. Take the head to the machine shop and have it mangifluxed and if it's good, get a valve job to clean it up. It sounds like you may just have a bad intake gasket, I would use a felpro gasket to replace it. |
I am willing to bet that a 365 magnum head that has been on a boat since 1989 is going to be rusted out. Fresh water,salt water,brackish water it dont matter, if it didnt have antifreeze in it ,like in a closed cooling system, to curb the corrosion it will be rotted out. 23 years is a long time for anything on a boat.
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it was a rot...water flowed into the exhaust port...pulling the other head tomorrow and having them both changed
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as long as you are buying heads, don't get more peanuts. go square port. your intake is about to rot through anyway...
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I don't know what you exactly found out but I just solved a similar issue with my engine. Was getting water in the oil as well as the exhaust manifold. Pull my hair out for a week. Turn out to be leaking exhaust valve guides. Magnafluxing won't find them only pressure testing will. Also DON'T use rectangle ports on a 330 engine, they're way to big and will also require a new intake. You can most likely get yours repaired at reasonable price.
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Wow, that's a new one...you want to repair peanut port heads???? I thought once they came off they were boat anchors ;)
Rectangle port (or large oval port) and a good and matching intake with the right mild cam combined with a slight compression bump is about the oldest 454/330 performance upgrade ever. I wouldn't just bolt on rectangle port heads without matching the combo, but keep it below 4800RPM and 400 hp is pretty easy to do, and pretty reliable too. Maybe you are saying don't put them on just by themselves??? |
Originally Posted by BBCLiberator
(Post 3734610)
Wow, that's a new one...you want to repair peanut port heads???? I thought once they came off they were boat anchors ;)
Rectangle port (or large oval port) and a good and matching intake with the right mild cam combined with a slight compression bump is about the oldest 454/330 performance upgrade ever. I wouldn't just bolt on rectangle port heads without matching the combo, but keep it below 4800RPM and 400 hp is pretty easy to do, and pretty reliable too. Maybe you are saying don't put them on just by themselves??? |
the water is pouring through his heads. they are too rotted away for use as boat anchors. means his intake is likewise rotted away. i believe his boat is a 206 formula. 3500 lbs with big block. i think boat will do ok with a little low intake air velocity at 2200 rpms. you buy a set of peanuts, you are locking yourself in at 330 hp. i am assuming he will be considering more upgrades in the future.
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boat is a 272 with twin 7.4's i have to update my profile...im just repair this one motor for now...i got cheap peanut ports and all the valves were ok...shop is changing everything over to the new ones this week...intake seems great. hoping the othe rmotor holds out...can't afford to tear into both of them right now...
in the future i would like to rebuild these 7.4 330s not mags...to about 400 hp each...i guess i should start collecting parts for that |
and first thing you need is better heads...check the underside of the front water passage on intake for signs of drip-through.
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