Automobile Transmission, why not?

well i guess your on to something but the transmission does`nt have a thrust washer and nore is it designed to be fitted with a thrush washer the out put shaft is designed to hold only rotational mas which it was designed for ..which holds no thrust the whole transmission is shimmed for thrust but only from clutch friction which is held within the transmission then sent to the output shaft... which bears no thrust

 

I saw it done once on a ski-race boat. It had limited success - at least in the race winning results.

The thrust (no pun intended) of the idea is that you can swing an oversized prop to lower the cruise rpm of the installation.

Ideally, the prop will be large (pitch) enough to allow the engine to comfortably power the boat at intended cruise speed at economical RPM. On a 1:1 conventional installation the prop pitch is a compromise between a pitch small enough to allow the engine to swing it at low RPM where it is not producing full power, and large enough that the engine is not revving it's head off at intended cruise speed. In other words, a prop with a large enough pitch to produce intended speed at economical RPM is too large for the engine to swing at low forward speeds and get the whole rig up on the plane.

Adding a 2 or 3 speed auto trans allows an engine to swing a larger pitch prop in low gear to get it planing, then shifting into high gear once on the plane allows a low RPM economical cruise.

The aforementioned problems with cooling and thrust bearings are another matter. I Built and maintained several ski boats when I was much younger, and they all had auto engines in them. Thrust bearings for 1 inch shafts could be bought at any bearing shop and making a bracket to mount them was child's play. You can run cooling water straight from the ocean even as long as you flush well after each use, but running on a fresh-water lake will not be a problem.

Cooling the exhaust manifold is a bigger problem, but water-cooled jacketed manifolds were easily obtainable where I lived in Australia. I even recall watching my Dad's 1960's vintage 30 footer with twin side-valve Dodge in-line-six's running at night with the exhaust manifolds glowing red-hot - uncooled at all!

So, I'd say, if you are a bit adventurous at all, give it a go!

 

Sorry to join this discussion with further questions regarding my own project. I wish to replace my 2 cylinder 7.7hp lister air cooled engine with a very reliable Isuzu 2500cc diesel engine onto a straight through gear box, no reduction. The engine will be lifted straight out of my old van. Thought as river use only I might use direct cooling from riverwater. Any great problems here? Boat is 9 metre steel ships lifeboat, pictures in gallery.
Pete Large

 

I agree with betelgeuse.

Many parts are easy to find and with the help of a good old fashioned steelshop you will get robust mechanical pieces which you can combine with standard non-marine parts.

Some people might not like your idea because they are reseller of marine parts, engines, etc,...

But you can make simple things work well. Allways think about safety!!!

Greetz,

Daniel Peeters

 

danielsan:
I find your statement that "Some people might not like your idea because they are reseller of marine parts, engines, etc,..." insulting. Read my comments and refute any if you can. However, slander in uncalled for.

 

Don't want to be rude

I didn't mean to get on someones toes.
But it is a real situation. For myself as project engineer I only promote my materials who wouldn't?
But in a forum like this people should come up with solutions for those who don't have the big money to spend for a boat. I agree that you let pay the lokal show-off guy(s) who don't care about their money. Don't do this to people having dreams and trying to realise them without having to win the lottery

There are other good solutions even for one-off and some people are thinking out off the circle.

So hope this can settle a bit the "misunderstanding" (didnt find another word)

Greetz,

Daniel

 

Auto engines and marine can be used in place of each other, period! They can not be interchanged if you do not know how to do it, period! GM and FORD and VOLVO do it for a living. If you expect the conversion to be as good as they do , never! If any of you are as old as I am, you would agree. We had no choice. I am going to use a Nissan V8 ( TITAN pickup ) closed cooling system using a shell and tube heat exchanger of heavy wall Marine grade Aluminum tube and a LARGE water pump sized by heat exchanger company, with a strainer . A second heat exchanger will cool the auto trans fluid - engine oil - and have a 180 degree thermostat to prevent sludge in oil. Raw water side - strainer - Y fitting for one way valve - LARGE water pump sized by same co. of heat exchanger . Cooling done. Engine changes all are USCG MARINE approved -distributor- carb/ 2 or 4 bbl- flame arrestor- starter - alternator 1 wire type all GM MARINE. Engine will have antifreeze in year round on ST. Lawrence River and NEVER corrode because it is running the same as a truck towing. ALL FULL SIZED TRUCK ENGINES THAT HAVE MORE THAN 4000 lb towing capacity have a marine cam to pull it all uphill forever!!! The Nissan V8 has a flat torque curve from 1000 to 3600 rpm and is rated @ 379 ft lbs of torque across that range, hp is 305 at 4900 rpm.. If we have nothing to believe except business people who want to make money, buy the marine engine. If you do the conversion your self- REMEMBER!!- you are totally responsible for what you do. I think I remembered it all without driving 7 miles. Nit pickers are allowed. OOPS- forgot the Rexnord two way spherical self aligning thrust bearing#zb-2102 rated for 1700# axial bolted to engine beds. Rich

 

Have you considered the added reliability of scrapping the extra pumps and heat exchangers in favor of keel cooling and dry exhaust?

Advantages in cost , reliability and best of all you dont have to winterize every day after use in the cool weather.

Used keel coolers are easily avilable and not too costly.

For a low speed (under 12K) boat simple water pipe works fine .

We cool a rated 200+hp 6-71 with 2 -20 ft pieces of 1 1/2 pipe and 2 elbows.

Came from Maine & Works fine in FL,

FAST FRED

 

I really gave " keel cooling " and several variants-flat bottom plate/ boxed welded shell inside and other ways. NONE of the non-pump ways allow long periods of idle, racing engine during adjusting of parts or tune ups, and just waiting for people and gear to be loaded. This boat is mine to be loaned to the Antique Boat Museum to take young kids out and let them learn and actually drive it. It will spend a lot of time running in gear tied securely to several dock cleats. I want the kids to know there are other ways to get exctied and satisfied. Hell, I was 9 and did not get juiced with 2 Chris Craft boat rides. I was 63 when I went out in a old restored Dixie III, and had the " hots " so bad, I sometimes forgot to have sex everynight. Few people really have the time and money to help kids develope with self confidence in starting something new on their own.

 

Richard Petersen:
Your snide remarks about business people are unwarranted. Many of us are honest people making a living through the sevices we provide. We don't put a gun to anyone's head to make them buy what we sell; it is their choice. As for a marine and truck gas engine being the same, it is not true. It was many years ago. Take the time to study new technology and you will see how wrong you are. For example, how are you going to make the ECU in the truck run without an oxigen sensor. How about the fuel injection system? The marine is a closed system that runs at a different pressure. Oil pans are also different because the angle of operation is much larger in a boat. Trucks blocks are cast iron, marine blocks are an iron/nickel alloy for corrosion resistance.

 

Mr. Gonzo. I have safely and reliably converted auto to marine engines at the NEW JERSEY shore for a good many of my 67 years . You on the other hand are a frustrated and probably unsucessful person. I made no remarks other than we are not all marine incompetent. You take childish offense at at anyone who does not agree with you. Grow up.

 

You do not read what people write here. I said RUN THE ENGINE IN A CLOSED SYSTEM. THAT MEANS IT NEVER FEELS THE WATER THE BOAT RUNS IN. IT HAS A MIXTURE OF 50/50 % WATER AND ANTIFREEZE !!! UNDERSTAND! EVER HEAR OF A MARINE DISTRIBUTOR A MARINE CARBURATOR 2 OR 4 BBL THAT IS ALL IT NEEDS TO RUN. computers-ecu-tcu- sensors are great but are not necessary to run the 2002 Mercruiser 5.0 L 220 hp 2 bbl engine in my Chaparall, factory installed. Are you a jet engine person who made a forced landing here? Rich Or a overzealous sales represenative of a major marine manufactuer. They would not like your hostile attitude toward their customers.

 

Bewildered

I just sat at a redlight with a Peterbuilt behind me, I almost crossed when I saw it, do you think it would be possible to rig one of those radiators up so that it would stand up when going slow but lay down when you were going fast? A radiator like that is probably good for somewhere between 5.000 and 10.000 hours - although that is not that much if you are circumnavigating. I was also thinking of using a motorcycle engine to drive the fan if I needed one - do you think it would get damaged in the rain?

Confused

 

Not if the umbrella is big enough.

 

Automatic transmission

I have seen many installation's of auto transmission's in vessel's up to forty feet.In the fishing village's of nova scotia, canada, most fisherman used this setup: The engine and transmission complete, were coupled to a driveshaft with a universal joint.The shaft was held steady with a bearing block, which had a thrust bearing on either side ( one for forward, one for reverse) to absorb the thrust from the propeller.An automatic transmission has no tapered bearing's for the thrust of the propeller, and would not last very long.
You may wonder how the transmission was cooled! A coil of copper half-inch tubing was submerged in the bilge water. Through this transmission fluid circulated and cooled the transmission.The engine was cooled much the same way with cooling pipe's mounted outside the hull.

Good Luck L .P.