[ntbush83]

I've got a question that may be stupid but I was just wondering. I know a lot of people talk about swapping automotive v8's in boats but the car engines aren't made as strong and don't have enough power that a boat requires. So if a boat engine is made "better" than could you put a boat engine in a car?

 

[ThatSilverStepside]

I dont know anything about boats, just that they are supposed to stay above water...but I suppose if a car engine can go into a boat its possible for the other way around..

 

[silveradotrailblazer]

Boat motors have reverse rotation so it won't work. If you buy a camshaft for a boat motor it is differant then a car/truck motor.

 

[Crawdaddy]

I don't think all marine engines are reverse rotation, because I swear I've seen engines listed in all 4 configurations : car/normal rotation, car/reverse rotation, marine/regular, marine/reverse. One thing you may want to consider is that marine engines are designed to be cooled by the water the boat is sitting in. I think the water pump is different because of this, but a car water pump should be cheap and have the same mounting bosses as a marine pump. You would also have to source a complete accessory drive for it, and the marine engine may not have the mounting bosses drilled and tapped.

That all said, a marine engine would be a nearly unstoppable force in a car. Marine engines are designed to run fast, with a huge load, for long periods of time. Sounds like a winning combination in my book. Marine engines also cost a lot more, if I remember correctly. Research it some, and I'm sure you'll find all the info you need.

 

[DAREDEVIL]

WHHHAAAAAAAAAATTTTT ...who told u boat engines are reverse rotation ??? BS

Yes it will work , boat engines are build a little looser then car motors on the specs so they can actually work at 5200 + RPM over a piriod of time since boats do not use a tranny. other then that its the same..if its a HP boat engine, u will have better exhaust valves and stuff too.

They are all chevy blocks and only the ones build between 1970-1985 come with the option of reverse rotation because back then the drives where all RH and a twinn engine boat likes both rotations to stay straight.....still very rare !!!!!!

The only differents on the cam would be the lift..they are all the same ....unless u have a counter rotating engine.

 

[silveradotrailblazer]

DAREDEVIL, that make sense about the optional '70-'85. My father-in-law had a boat with twin Dodge 440's and when they were rebuilt I remmember the cams had two differant part#'s. His boat was a '83 houseboat.

 

[wis bang]

I knew a former motorhead who found himself in need of a smallblock Chevy in a hurry, he grabbed the phone and called the boat engine guy down the shore and had a re-man delivered the next day...

He pulled his El-camino in the back of our shop that night and had the 'bad' engine waiting there for a core. He was back on the street after two late nights. He woulda been sleeping there in the bunk in his Peterbilt anyway...

My boss never knew I let him use our shop....

 

[MonkeyBiz]

The big issue would be cooling. The easiest way would be to pull the crank, rods, pistons, head, valves (which are all forged), essentially the internals and put them in a vehicle motor.

 

[tbplus10]

You normally only find reverse rotation engines if your running dual engines, but thats not guarantee, the rest of the time they'll be normal rotation engines.

Cooling systems can be different but most times Marine engines run a normal water pump, many saltwater used boats have a closed loop cooling system exactly like an automobile.

The largest difference is the marine designation, except for electronics (alternator, etc) Marine and normal automotive items are similiar but if you ever get stopped and get an in depth Coast Guard inspection they will look for certain engine components to be Marine designated.

Marine engines bolt up to many popular transmissions and theres hundreds of distributer and ignition applications available for them.

 

[ntbush83]

wow thanks for all the input! yeah I knew the cooling system would be an issue but that was the only real issue i could find. But those boat engines are mean! Mercury makes v8 engines that push 1075 horse stock! It would definitely be a cool project if it worked out. Swapping the internals is also a good idea. I never thought about that ha

 

[DAREDEVIL]

You normally only find reverse rotation engines if your running dual engines, but thats not guarantee, the rest of the time they'll be normal rotation engines.

Cooling systems can be different but most times Marine engines run a normal water pump, many saltwater used boats have a closed loop cooling system exactly like an automobile.

The largest difference is the marine designation, except for electronics (alternator, etc) Marine and normal automotive items are similiar but if you ever get stopped and get an in depth Coast Guard inspection they will look for certain engine components to be Marine designated.

Marine engines bolt up to many popular transmissions and theres hundreds of distributer and ignition applications available for them.

where do u guys get that wrong info ..on the reverse rotation ????????????????????????????
a boat engine is just the same as a car engine !!!!!!!! Only cam and spec on clearance is different, u can stick any boat engine in a car but u cant stick a car engine in a boat ( it would not last the RPM ) !!!!!!!!!!!!!
ofcoarse u need to change a few things like hoses and sensors and turn the timing back...but other then that it should bolt right in..i would also change to a car oil pan...if it has a marine on there .

But they turn 100% the same way ...all standard rotation LH from looking at the back of an engine !!!!!! A lot of people look at the front and think its RH ..ITS NOT ..its always from the bellhousing /Transmission looking forward !!!!!! So standard rotation is LH and counter rotation is RH !!!!!!
If u look on the distributer. a LH engine turns RH on the distributer !!!!!!

HOPE THIS HELPS !

Sorry

 

[murdog94]

One thing to remeber is that some of the marine engines are very heavy compared to their auto counterparts. I have a 3.0L mercruizer with 140 HP that is based on the 2.5L chevy Iron Duke. And it is quite a bit heavier than the 2.5L (not sure of exact pounds). Also yes 5200RPM is some boats are tuned to but most inboards, and I/Os are designed to run below 4500RPM, and you control the pitch of the prop from their to bring the RPMs down. Usually there is a lot more torque tuned for these motors, and cooling isnt an issue at all. As long as you have good fans and a good radiator. I run mine at 3850 rpms all day long. So i would put marine parts into a auto motor for the weight savings and they would work best in a truck to get all that weight moving off the line and down the stretch. In a car they would run out of RPMs and power way to fast.

 

[DAREDEVIL]

not true...sorry,,,on the run out off power thing,,, a 454 V8 marine has 330 HP and the 454 magnum has 365 HP and about 300+ FPT at 4000 RPM...on a car u have a transmission to make up for what the weight of the vehicle is so the engine can push it ..a boat engine will turn over easyer then a car/truck engine since its designed with more power from the factory !! just saying....and i dont want to step on your toes either murdog..lol

 

[murdog94]

Oh i get that i was meaning that moving a lighter car with a lower power band (most drag engines and high end high output motors) that are built for cars have power well into 5K RPMS. That was my referal. since moving a truck needs more power from idle to 4000RPM a built marine motor would be well suited, out of the box was my reference since most marine motors make thier peak power just before a truck would shift (so you are able to take advantage of the entire up side of the power curve) and in a muscle car an out of the box marine motor would fall flat on its face just before it was time to shift (i was running well into 6K prms with my 327 small block "built") equalling a loss in acceleration.
Hence my vote for it being a great option for a truck. I was attempting to simplify my explination but i guess i lost it in translation. And in a car you would need to move the power bad, hence why most muscle car guys have a stall converter that is 2500RPM or higher. And trucks usually arent much above idle to 2K RPMS since their motors are tuned for torque, which is how my 16Ft boat that is in the 3000lb range can get out of the water, and on plain and to 38mph In a hurry, and playing with the trim (taking advantage of the higher RPMs and HP) adjusted right it feels like i hit the 4barrels on a 350chev, and am at 52mph. at a comfortable 3850Rpms, and using a ton less fuel.
So my vote is once again go for it and do a write up to let us know how it goes!!!!!!

 

[ntbush83]

alright sweet this makes me want to do it even more now! if all works as planned this will be a one of a kind power machine

 

[DAREDEVIL]

gotchya murdog...i missunderstood your post ..u are correct !!!!!

 

[tbplus10]

where do u guys get that wrong info ..on the reverse rotation ????????????????????????????
a boat engine is just the same as a car engine !!!!!!!! Only cam and spec on clearance is different, u can stick any boat engine in a car but u cant stick a car engine in a boat ( it would not last the RPM ) !!!!!!!!!!!!!
ofcoarse u need to change a few things like hoses and sensors and turn the timing back...but other then that it should bolt right in..i would also change to a car oil pan...if it has a marine on there .

But they turn 100% the same way ...all standard rotation LH from looking at the back of an engine !!!!!! A lot of people look at the front and think its RH ..ITS NOT ..its always from the bellhousing /Transmission looking forward !!!!!! So standard rotation is LH and counter rotation is RH !!!!!!
If u look on the distributer. a LH engine turns RH on the distributer !!!!!!

HOPE THIS HELPS !

Sorry

That is incorrect look at early 70's Chris Craft Dual engine Big Block applications.
Chris Craft offered dual engine 454's in a 24' to 32' cuddy cabin model boat that had 1 reverse rotation 454, I've heard of a reverse rotation 350 option for these boats also but never seen one.
Rotation direction was not reversed through the gearbox, the engine was a reverse rotation.
I owned a 1974 Chris Craft 28' with this configuration for a few years.

 

[murdog94]

Agreed but it depends on the motor you can get them with either rotation. Just make sure its the right way.

 

[tbplus10]

Agreed but it depends on the motor you can get them with either rotation. Just make sure its the right way.

Yep, I was just researching this subject, boating forums seem to have the most info but it appears there are many marine engines designed to run reverse rotation, Mercruiser 350's seem to be the most popular but there were 454's and even 6cyl and 4 cyl engines of all different sizes offered in this configuration.
While Ford and Chrysler engines are found in Marine applications I havent seen any information on these engines being found in a reverse configuration.
One site had tips on how to spot reverse rotation engines.
Almost all sites agree camshafts, R/R main seals, must be changed when converting these engines to normal rotation and the oil pump and distrubuter gears need to be changed.

 

[bby366]

The port engine turns clockwise,the starboard engine turns counterclockwise.A single engine turns clockwise.A boat motor is high torque.It would have to be recammed and/or changed as to rotation.They will not interchange without work.Now who knows why it is called portside,and why.