Difference between auto and marine engines

"Besides all the "legal&#3

"Besides all the "legal" stuff aside, would lets say a built automotive 454 work in a boat? I know marine engines have brass freeze plugs etc, but if you use all marine accessories would it work? I can pick up a 454 on ebay cheap compared to a marine motor which is more than twice the price."

"There will be all sorts of op

"There will be all sorts of opinions on this, but the answer is yes. The question is how long it will last. Some internal differences include the following:

*different cam profile - shorter duration and lift for torque and lower risk of water injestion through exhaust valves
*marine head gaskets
*4 bolt main bearing journals for increased rigidity (some engines)

Keep in mind that a marine engine operates at a much higher duty cycle than an automotive engine... designed for operating at 3/4 of max rated power for much longer periods."

"What type of 454 is it?
Buil

"What type of 454 is it?
Built for the drag strip, sports car, full ton pickup for hauling or running a generator at a hospital?
Each application has different demands on the engine.
One might want to match the engine for the application.
The engine you get off EBay may save you some money, after you get done adapting it for marine use you might not save any money."

"If you are replacing a blown

"If you are replacing a blown marine motor and can re-use all the accesories, then you are good; notwithstanding what was said above.
Otherwise, you will need a marine starter, alternator, carb, flame arrestor, fuel pump, ignition sytem, manifolds and risers, bellhousing & coupler, etc, etc. The list goes on, and using any of these items that are not rated for marine use brings on big liability issues. Not to mention your insurance company will walk in the event of a loss, if they can prove the loss was due to the use of non-marine components.
The gamble is yours.
Rod"

"Ayuh,....... I pretty much Ag

"Ayuh,....... I pretty much Agree with everything said,.......

While there are many factors in choosing Which components will be used for a V8 motor,....
It mostly hinges on the Cam used in the build up........"

"You should match the engine a

"You should match the engine and it's horsepower to the outdrive. Alpha drives are now designed for big block or high power engines!! Bravo drives are, to some degree. Really high horsepower engines take another type of outdrive but I cannot remember what they call it. Usually Alpha drives are on family boats of all types with horsepower ranges of about 250 or less."

"[b]"Alpha drives are now

""Alpha drives are now designed for big block or high power engines!!"

I Don't Think Soo......
300hp is about where Alphas, All Alphas start to Come Apart.........

Bravos are Reasonably Dependable up to Near 500hp........"

"Oh gee, wish I had proof rea

"Oh gee, wish I had proof read my post!!! Substitute NOT for NOW. I meant to say they are NOT designed for high horsepower and since the coffee had not kicked in good yet I wrote now. They are not now or ever have been designed for high output engines....appologies to everyone!"