Afternoon chaps,

I have been given an old drag boat with a nice 460 in it. The engine has been built over the years. Currently with an unknown aluminum intake, iron heads, holly 750, msd 6al, and a nice probillit dist. I was told that it's been punched out to 472 and at one point ran nitrous and has an unknown but aggressive cam.

The engine is planned to go into my 1979 f150 4x4. Currently it has a 400 in it.

What kind of things might I need to convert from marine to Street?

Will it be more cost effective to have headers made or buy mad dog?

 

One question would be how was the marine engine cooled? It could either be "raw water" or "fresh water". Raw water would mean pumping water from the lake or ocean directly through the engine. Fresh water would mean a separate cooling circuit with antifreeze (hopefully) and a heat ex-changer to act as radiator and transfer heat to the lake/river/ocean water.

If it was raw water cooled, the water jackets may be in a pretty rough condition... especially if salt water.

Marine engines in general and especially drag engines are usually built with increased cylinder to wall clearance. It may want to clatter and use more oil.

Depending on how you want to use your truck the hot cam may not be so nice. For truck duty something milder may well be more suitable.

This may be a tough and frustrating project IMO.

 

The boat was set up to take raw water though it was never exposed to salt. Fingers crossed the water jackets arent going to be an issue then.

Could you explain a bit more on the cylinder to wall? Why is this done?

I'll at least start the engine with its current cam before ordering a new one. I expect marine cams are made to run well for long periods at a specific rpm rather than varied like with a truck.

As always there will be issues. But for a free 460 I can't pass up the oppertunity

 

I would agree that this would be a highly frustrating swap. Boats are made to run well at high rpms. You will end up buying parts that would normally come with any motor donated from a car or truck. Unless you are building a race truck.

Personally I would sell the boat or keep it as is and find a better 460 donor.

Without seeing how it is setup, you would likely need the following that I can think of just for the motor alone...

Distributor-recurved for truck
water pump
timing cover
dual plane intake manifold(better for low end torque)-if it has a single plane already.
thermostat and water outlet for 79 truck or van.
Exhaust manifolds or headers custom only if you want.
flexplate or clutch?
Fuel pump if mechanical is used
Street carburetor
trans kickdown linkage and throttle brackets as needed

If you are really determined to do this swap it will cost more than the alternative. If the motor is cammed for a boat then you will probably be disappointed. It could be worn out already too-nitrous would be concerning.

460ford.com is an excellent resource for questions like this and they have boat guys too. So you might find better answers there. I bet someone has already asked the same question over there.

Sorry to be a debbie downer but having done a 460 swap they can get as expensive as you want them to get. I would rather save on costs obtaining the right donor engine and be able to spend it elsewhere to make the motor what I wanted for the application.

 

Hold the phone... First off, what's wrong with the 400 motor you've got?

If there's nothing wrong with the 400, why are you doing the swap? Lets get some background here

 

In the last few years, people have been rebuilding 400s into decent/good/excellent/fire breather motors.

For a lot less money, you can empty your current 400 of it's pistons, cam, intake and maybe more, and add compression, cam, a fresh bore, 4bbl intake or even EFI if you want to go nuts, and have lots of power, probably over 100 lbs less up front and none of the small nagging issues of the 460 swap, let alone the go-over that boat motor needs to be truck-rated.

Serving suggestion.....

 

Hmmm.. this reminds me of something... Oh wait, that's right

My build

 

Look the engine over closely. A lot of boat engines have cracks in the block and leak. It's no big deal in a boat but once you put in in your truck it would be a big deal..

 

Nothing is really wrong with the 400 so to speak. I drive it daily. It leaks oil like a civ and could use a timing chain. It makes alright power, but it also won't blow the tires off. I've wanted a 400 since I've owned the truck. Just something I've drooled over. So when the oppertunity presented itself for a free one, I couldn't say no.

The 460 is something I can prep on the stand and continue to drive my truck daily.

Pulling the 400 for a build up is an option, just not one I'd care to do. I know tmyer has moved leaps and bounds for making the modified engines a powerhouse. But for my money, I'd rather spend it on a 460 than a 400.

At the very least I have the nice goodies and an engine block

Fingers crossed the block won't have water jacket problems or be ragged out. If that is the case I'll look for more information on the cam and see about swapping. The single plane (presumed) intake is fine with me, I've run one on the 400 for years. The carb is just a standard double pumper, I have a 650 version of that on the 400 and really like it.

I'll be heading over to check out the 460 website, thank you for the direction!

 

Some marine motors make good swaps into trucks and cars and some don't.

Boats do not have vacuum advance in the distributor, that's not to say you can't put a mechanical advance only distributor on a truck but it will probably hurt mileage. Your 400 distributor can be swapped into the 460 though.

If the 460 was really built for drag boat racing you might want to be careful about the compression. The very linear loading of the motor in a marine application leads itself to being able to handle much higher compression on pump gas than in a on-road application.

The cam may be ok for the truck or it may be way too big. You may want to find out what the cam is prior to putting the motor in the truck... it's WAY easier to swap a cam on an engine stand than in the truck.

Have you checked the 460 oil pan? it's possible that the pan will fit your truck but marine pans are often different.

The thermostat housing may be different for marine than for a truck.

Do you know the year of the 460? This will tell you if it's internally balanced or externally balanced... from that you can determine what flex plate or flywheel you will need. One thing to watch for is it is possible that the flywheel end of the marine 460 crank will be different than the truck version and this might be a killer for the swap. Most are the same but I have heard of ones that are different.

After all of that I would think it would be better to sell a running boat, take the cash and build a good 400 or 460 that you know the internal parts are right for your truck.

 

On cylinder to wall clearance... a typical fixed pitch prop keeps the engine well loaded. "Fast Cruise" in a boat would be like a pickup pulling a tough hill with heavy trailer. All the time. The engine makes lots of heat and the piston expands. Also, marine cooling systems can keep the block cool so it does not expand so much.

The piston is built loose so it does not stick under "boat" conditions.

 

boat engine cam profiles tend to be more of a split duration, like more exhaust as well, keep in mind also that boat engines have absolutely no provision for air cleaners, egr passageways, mechanical advance only, boats are SUPPOSED to run a 140 thermostat on account that the water won't boil and overheat the bellows and vaporize anywhere, so this accounts for some condensation to build in the oil and crankcase since they never get hot enough to steam it out, causing its own issues that cause boat engines tohave a shorter lifespan than cars even with better or "stronger" components from origin. Boats are very likely to have water in the fuel and end up with quick deterioration in the intake valve and guide area.
This boat 460 is likely to be a good engine, and 460s are pretty hard to hurt, but just remember that it has been subject to a harsh life and I would recommend tearing it down before using any of it.