Tigger

ok heres the deal, im buying my first boat. 79 ****ury 22 cuddy (not a gofast boat, but you gotta start somewhere), the motor is a merc 305, and its broke!!! (yes im getting the boat cheap) i have some experience in rebuilding a motor, the problem is im not sure what would make a reliable motor for my boat(without dumping $$$$ into it)i now have access to a chevy 350,out of a 79 nova(motor still running) hopefully someone can point me in the right direction???

puder

you woudl need to marinize it. To do that youw would need to changed the alternator, starter, coil, distributor, and any other electronics/electrical components. You will also need to change the cam to prevent reversion and optimize power for marine use and the freeze plugs to brass. You might also need to change your intake manifold if it aluminum. You coudl maybe also need a carb change. Automotive carbs canbe run on boat but can void insurance claims is they cause a fire. You might also need to re-jet the carb.

It might be cheaper to find a takeout somebody is selling here. Good luck and congrats on the new toy!

Bruce

How broke is your engine now? The biggest difference's are internal clearances due to the cooling water being single pass and cold. The clearances are opened up because the engine is always under load and the block/heads are subject to cold water. If you wanted to take a chance, you could install brass freeze plugs and a marine camhaft, the rest of the accessories would just swap. Have fun.

Tigger

thanks guys, but now ive got a couple more ?'s now. Puder, whats the differance between say a stock cam and a marine cam? and what is reversion? can i order a marne cm from somewhere or do ineed a specific cam profile? Bruce, the motor in the boat is getting water in the oil, so im expecting the worst, and im not sure how well the motor was winterized... which clearances are you taling abut, are marine motors built a little sloppier than standard, like you would in a racecar? (family races 3/8 mi high bank modifieds) thanks again guys

Sacandaga

Save yourself a lot of headache and buy a rebuilt long block marine engine if you have useable parts from the stock 305. If not, many offer turnkey packages for about $3,500. www.repropower.com is just one site. There are more ads listed in Boating & Powerboat magazines. You might spend more to begin with, but you won't have any problems in the long run. Just my .02. Good Luck.

Wally

iTrader: (1)

depending on how much water there is, and where its coming from try and see what the problem is first before going through with a different engine! It may be as simple as an exhause riser gasket! $35 and you could be back on the water!!! check it out first is my advice before dumping thousands into it!

Lee

iTrader: (4)

Right on wally.

Greg Mc

I would check the marinas in your area for a take-out. By far the cheapist and easiest way to go.

TwoKs

Johnsnow,I would try what Wally suggest first before removing the old engine. Also check to see if the water cross over under thermostat housing hasn't rotted through and dumping water into the lifter vally.If you do marinize the 350 engine, you should also change the head gaskets.Automotive ones get kind of spoungy after a while.Good luck with your new toy

NW_Jim

Automotive camshaft will have a narrower lobe centerline of say 109° or less whereas the marine cam will have 110°-114° or so to reduce reversion. Reversion is when water gets sucked back into the motor from the exhaust while idling. Not good. The marine cam will make more power.

I would guess worse case should be a head gasket. If you know engines, your best bet would be what Wally said, then check the head gaskets if it's not riser gaskets. Your much better off working with an orignal marine engine then trying to build one from an automotive application IMHO.