diff. between car and boat engines?

[HyperDonzi]

ive been wondering for more than a year, what is the difference between boat and car engines, i know car engines typically are run at a lot lower rpms than a boat (theres no tranny). what else is the difference?

[FlatRacer, aka BarrelBack]

Car engines go "vroom vroom", but boat engines just go "WAAAAAAAAAHHHH!!!"

Sorry, I'm a little punch drunk from all those BBQs.

Eric

[harbormaster]

Cam, freeze plugs, and head gasket. The distributor, carb, and I believe starter are different.

[HyperDonzi]

what would the head gasket have to do with it?

[harbormaster]

If memory serves me correctly, it is resistant to corrosion. Someone else what to address this/

[CDMA]

While new composite gaskets has changed this to a large extent the issue is that automotive engines tend to use a steel core head gasket. This does not fair well in salt water. So a complete composite or stainless core gasket is needed.

Chris

[Formula Jr]

Valve springs are stronger, oil pans usually have a baffle in them, fewer smog control devices, the voltage regualtors are sometimes water cooled, Older boats have far simpler wireing harnesses, Plug wires are stainless, and all marine grade wires are tinned thru out their length, Carbs have float overflow tubes that bend into the carb throats, The fuel pumps are setup so they can not vent if there is a failure, Spark Plugs are different, and all componets that can generate a spark; starters, distributors, altenators - a back fire protection via a Flame arrester - have fine mesh screens used so as to prevent an explosion if there is gas vapor traped in the bilge. The engine is also typically straped to an anti-corrosion anode system. Everything is also expressed in Boat Units as opposed to Dollars. A Boat Unit is equal to about one thousand US Dollars. But this is regional. In Miami, one BU is equal to about 1500 USDs.

[MOP]

Hi guys my 2 Cents! Hypernetic pistons, very high grade bearings, cam shafts are a tough item have to be ground so you don't suck water back into the engine, and a number of marinizing items which can vary from Salt to Fresh use. The first thing that seems to let go on a car engine is the pistons. I've had alot of guys that were short on change put car motors in their boats (mostly junk yard stuff) most did not get much time.

[Greg]

I believe the water pumps are different also, with bronze impellers and bearings.

[Boat_Mon]

Formula Jr.

I was with ya til you mentioned the spark plugs are different. Please expand .

[Formula Jr]

Stainless....and the heat range is slightly higher.

[Gary S.]

I've been told the piston to wall clearances and ring gap are slightly looser on marine engines because of the cooler operating tempeatures.