I think that what you all are trying to say is that for normal pleasure boats (not like ferrys or anything of that size or weight, just something like your normal boston whaler) is that for boats it is important to have high RPM power, whether that is torque or horsepower. A very good moter for a truck to tow with might not be a good moter in a boat, because it develops it's power down low. While a car needs it's power at between 2-3K RPM's for cursing, a boat needs it at like 4-6K RPM's because that's it's cruising engine speed. Big boats can use diesels because they usually don't go as fast, weigh more, and swing big propellors, which moves you farther in one rotation than does a small propellor. Therefore, small propellors need to turn more to get the same distance, thus using higher-reving gas engines.

 

There were a ton of 460's in boats, back when the little jet boat with a big V-8 and pipes stickin out the back got popular in the late 70's or so. I remember all the heated conversations between us guys, "454 Chevy's bend their valves, the Olds spin bearings, the Fords broke off exhaust manifolds". No matter what the other guy had, you had the better powerplant because the other guys motors would do "X" if "X" happened. I think the Ford had a knock for their weight too. But none of these big iron blocks of the 70's would rev, they were all torque monsters, which was good. Except all us jet pump guys would plant the gas pedal to the floor and rev them to death hoping to go faster than about 3500 rpm would push us. But we didn't, the pumps were too inefficient (remember prop'd V-drives BLOWING by you on the top end?) and the motors fell on their face after 4500 rpm or so. Water cooled chrome headers pokin up in the air, scoops that looked like superchargers, GM 6-71 blowers, all with stock bottom ends, we scattered alot of engines trying to turn them to small block revs. It was fun, and much cheaper to pick up a short block if you did grenade you lower end. I think a V-10 and a V-drive would be killer if you wanted speed, Ken

 

All Ford engines are available for marine use.Ski boats have Fords because of superior trq figures with the Ford.I have a 24' commercial shrimp boat with a 350 Vortec marine engine made by MarinePower,325 horse,don't remember the trq #'s.Hyd roller cam,Edlebrock intake and carb.It runs great.The ONLY reason it has a gm engine is it was already set up for a gm.Trq is the name of the game in marine engines.My engine has a rpm range of 0-4400 rpms.

http://www.rbbi.com/company/ford/fpr1.htm

 

A couple of observations on the V-10 vs. 8.1L debate: The 8.1L is a modernized version of the old 454, which is where both its strengths and weaknesses are. It is all cast iron, has 6 bolts around each cylinder, and even though it isn't a deep skirt block, it has 4 bolt main bearing caps and very thick main bearing bulkheads. That adds up to a real durable engine, and is probably the reason you still see them in heavy trucks and marine applications. But, it is a very heavy design, uses a bit of oil thanks to its 4.25" bore, and relies on a 1965 cylinder head design. The V-10 is much more state-of-the-art, is a lot lighter, finally puts out real power thanks to the new 3 valve head, and delivers better fuel economy and emissions. But, it is a small block car engine with 2 additional cylinders, only has 4 bolts around each cylinder, has aluminum heads, and a pretty thin block (you can still bore a 8.1L .060 over if you wanted to). Which is maybe why you don't see them in trucks larger than an F-550 or marine applications.

 

thosetwins,

Hey I'm not knocking either one of the engines, but every boat I've owned has always had a chevy motor in it. Why, I don't know. Maybe it has something to do with the whole manufacturer affiliation thing, i.e. Ford & Firestone until the whole Exploder, I mean Explorer, thing. And no I've never owned a "real sportboat". Sorry the military doesn't pay me 7 figs. My truck works and my boats fish. And yes 496's will produce a ton of torque. If you can't make torque with that much displacement, you have some serious issues. But if you look at it, liter per liter, inch per inch, Fords make torque and Chevys make horsepower. Sport boats need horsepower. Horsepower is easy to produce, just add RPM (Chevy). Torque at low RPM is much harder to produce. You have to look at the application that is being used in. If a vehicle, say a nascar or sprint car, is used mainly at high RPM you will tend to see the motor tuned for horsepower. If it is used mainly at low RPM, trucks, you will see it tuned for torque. If you pull apart 2 motors, same make and displacement from a marine application and a truck application, you will see totally different cams, heads, and intake setups. That's what I was getting at. I didn't mean to ruffle your feathers that your twin 496's were slow or anything.

v10klzz71s,

You're talking about a commercial shrimp boat. That is a boat that needs torque. It's a snowplow on water. The engine is under a constant high load trying to push it through the water. Look at the pitch on one of those props, it's probably something that a sport boat guy would think is rediculous. A boat that planes doesn't need that kind of torque once it's up on plane, that's why you can back off the throttle and still maintain the speed. That is comparing a tractor to sprint car. Again specific design for a specific application.

An lastly, I'm a firm believer in the old adage of, "There is no replacement for displacement", unless you use in the wrong application, then your're just wasting gas.

 

Ford's V10 is factory spec'd to tow up to 18,600lbs in certain configurations of F-Series trucks. Some of the trucks this engine goes in have GCWR as high as 26,000lbs.

No offense intended, but I have a hard time calling it a "small block car engine". I can't think of any car engines that tow almost 19,000lbs or power a vehicle with a GCWR of 26,000lbs. In fact I can't think of many other gasoline truck engines being currently produced that are factory rated to do that kind of work!

 

I really want to see the 8.1 and the new (3-valve) 6.8 on the dyno, would be interesting to see whats really making the most power, the factory tends to make up power numbers when it comes time to put out a engine. Anyone have 8100 and old 6.8 dyno figures? The 8.1 is strong and powerful, it does get bad milage and use some oil. The Torqushift and the Allison have the same gear ratios except for reverse, I have a hard time believing the Allison sucks much more power then the Torqushift. From what I have heard the old magazines have said that they run about the same, 8.1 a little quicker loaded and the 6.8 a little quicker unloaded, maybe the new 3-valve will kick some a$$. I plan to get a new SD in the future and it's looking like a 6.8 with 4.30's and a Torqushift, should be a pretty powerful truck. I have driven a couple 8.1\Allison's and they were really quick and torquey, power was smooth and ddn't fall off, if the new 6.8 feels like it I know I will be happy, I have drove 3 new 5.4's, can't find a 6.8 to drive, some day...

 

The Chevy is a large bore engine. In order to pass emissions, Chevy has to detune it to a point where it's not efficient anymore. The 6.8L utilizes a small bore, long stroke design that most manufacturers use to get larger engines to pass smog.

 

The V-10's towing and GCWR ratings are impressive, but just for comparison, the 8.1L is used in trucks up to 33,000 lbs. GVW, with a GCWR of better than 60,000 lbs.. Diesel territory. The old 429 Lima truck engine in the early F-700's was capable of similar numbers, too.

 

Once Ford figures out which size carburators it's gonna go with,
their new I10 will put an end to the "who's the biggest" once and for all...

 

lol!!! That's just wrong, I would have to say I would be the first one in line.

 

Agreed.

 

BFR250SD,Actually my boat is almost flat on bottom,is 9ft wide, and runs 39 mph with a 17X17 3 blade brass prop.I can slow to 2800 rpms and stay on plane. The boat actually had a 454 in it.It looks sorta like this>
http://www.impact-enterprises.com/photo/0223371f.jpg

 

The 429 was used in the largrest of Ford Trucks L800 & L900 Louieville line of trucks.

 

One of the problems with V10's in marine applications is the aluminum heads and other parts - hard to make it run on sea-water And if it IS salt-water, it has to run at 140 degrees or less.

If it's a fresh-water closed system, then it's doable, but for what most people have 454's and bigger motors in, the V10 would be way too long, way too tall, and the fresh-water cooling system (and heat exchanger) would take up so much room, it would be ridiculous.

My brother-in-law is in the wholesale marine engine parts business, and Ford has basically given up the Marine market to GM. They just couldn't compete with the low-cost of the GM stuff.

Why is GM used in the marine industry almost exclusively (100%?) ? They are cheap, easy to repair, and small. Emphasis on CHEAP. Put a marine cam, brass freeze-out plugs and a double-roller timing chain (and the right oil pan) and you have the standard GM marine motor - nothing special ... need to rebuild one? Any crank-cutting shop will have plenty of GM cores - any machine shop can handle a GM motor - any junk yard has auto motors that can easily be turned into marine motors...

And besides, marine motors are beaten to snot, most people don't maintain them changing oil/plugs/filters, etc., and you're lucky (here on Long Island with salt-water) to get 5 years from a motor - so... given those choices, a CHEAP GM motor makes a lot of sense.

As for the GM vs. Ford motor debate, well, let's just say I've never owned a Chevy, by choice... as for the 8.1 vs. the V10 - well, hands-down, the V10 is smaller, yes, but it certainly gets the job done. And I own an '01, not the 3-valve.



art k.