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Old 11-10-2013, 11:10 PM   #21
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rjtrane,
You are right ...

BUT .. they made cars w engines in the stern too. But they were not ideal.
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Old 11-10-2013, 11:22 PM   #22
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Porsche, Lamborgini, Ferrari?????
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Old 11-11-2013, 06:04 AM   #23
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>You're the biggest supporter of Detroit Diesels<

Since an 8V71 is in my 4106 bus , a 6-71 is in my Utility , and a Series 50 in my VL-100 coach ,
I am familiar with operating and repairing them.

I would not install a 3000lb DD of any vintage in a 30 ft power boat , when a tiny 4 cyl can produce the minor HP required for a few hundred pounds.

Our 23 ft Regal has a 305 and Volvo dual prop setup and is fine at about 20K , but it would not be a choice for distance cruising as the IO is nowhere as reliable as a single shaft and prop.

The IO can tip out (partly) so eating a lobster pot might be easier to clear , if the IO survives the sudden stop.

Diesels are perfect where they can be used as designed , hard,hard work for long hours.
Not the requirement of most yachty marine motorists .2000 hours a year not 200 would make diesel the choice.

For a substantial cruiser (45-55 ft) the International 360 would be my first choice .

These are very inexpensive to purchase and are industrial built so an inframe , not throw away would keep it running .
The 360 and bigger brother have std SAE bell housings so a Twin Disc could be attached.Keel cooled , dry stack, almost as cheap to install as a gas engine, but with a longer operating life .
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Old 11-11-2013, 11:22 AM   #24
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Bob,
VW, Corvair, Tucker.

Don't know about the Italian things but all rear engined cars seem to be a failure except the Porsche. And being German it dosn't need to be a design success. They make all their odd designs look like they've seen the light and the rest of the world is in the dark. Air cooled VWs and BMW motorcycles w the cyl heads right where one's feet belong come to mind.

Outboards on the stern work well because the're light. Not so much anymore but compared to an IO w a car or truck engine plus a big heavy IO even the 4 stroke OBs are light.

I'm not say'in engines in the stern don't work. I am say'in engines placed near the center of the boat work BETTER. Balance is a huge part of boat design and the engine in the center of the boat can't be beat.

FF,
IH is belly up aren't they? You're suggesting rebuilding old farm machinery and marinizing it? Never heard of an IH in a boat. But before they did it never heard of a JD in a boat either. But they still make JDs. The're are no marine engines anymore so all boat engines come mostly or entirely from cars and trucks. That in itself is bad but an economic necessity. What is an IH 360? Six, 8 cyl and how long ago did they stop making them. Is it an extremely common farm engine and w parts readily availible? And if it's such a good engine why aren't boaters regularly replacing their Lehman's w the IH 360? If I had a tired or screwed up Lehman I'd want to know all about this IH. I think rebuilding a Lehman is a questionable undertaking just so one dosn't need to fabricate new engine mounts. Surely there are other good engines too.

I'm not knocking the IH engine FF. But you've mentioned it many times over the years and no real information has surfaced.
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Old 11-11-2013, 12:17 PM   #25
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Eric,

Touche' but I do like a Ferrari!
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Old 11-11-2013, 12:41 PM   #26
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"Aerodynamics is for people who cannot build engines"-Enzo Ferrari
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Old 11-11-2013, 03:34 PM   #27
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I personally don't like I/Os..but they do have plusses as well as minuses...you just have to live with the minuses carefully.

As far as boats not working with I/Os...when I worked for a Sea Ray dealership...Sea Ray had just about phased out all their outboard boats and sold exclusively I/Os except above 30 feet where I/Os were an option with inboards taking over completely by the 37 models (I think)...

So to say inboards are better or I/O's make a boat stern heavy is just silly as Sea Ray has became a household word and one of the most successful boat buiders.
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Old 11-11-2013, 03:53 PM   #28
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Grantm - My suggestions:

Pleasure boats under 45': Good condition gasser twins with straight drives on planing hulls.

Nearly all size boats: Full D's and most Semi D's single or twin diesels.

Over 45': Single or twin diesel... planing or not!
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Old 11-11-2013, 04:37 PM   #29
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Grantm - My suggestions:

Pleasure boats under 45': Good condition gasser twins with straight drives on planing hulls.

Nearly all size boats: Full D's and most Semi D's single or twin diesels.

Over 45': Single or twin diesel... planing or not!
While not a bad rule of thumb...it really does depend on how it's going to be used and how much you want to customize a drive train.
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Old 11-11-2013, 06:17 PM   #30
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Porsche, Lamborgini, Ferrari?????
Happy to be corrected, however I cannot recollect any rear engine Ferrari's, quite a few mid engine cars, but that a different animal altogether. Ditto for the Lamborghini.

Actually, this post is just an excuse to post my boyhood dream.
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Old 11-11-2013, 06:19 PM   #31
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Bob I don't think Ferrari built a rear engined car. But they did build mid engined cars that were very well balanced. The engine was ahead of the rear axle.

Still I don't think any car maker made a success of a rear engine car except VW and they saw the light eventually.

As to boats w IO drives in the stern one could attempt to balance the boat by putting things far fwd. Not much else heavy except people and if you put them far fwd the'll have a very rough ride and the waves will be pounding on the bottom of the center of the boat where nothing is and the weight at either end will be constantly trying to break the boat in half so it will need to be strong. Just more unnecessary weight.
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Old 11-11-2013, 07:05 PM   #32
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Your right. VW finally saw the the light. In 2013! After ONLY 1.5 Million Kombis (the classic VW bus), VW in Brazil is admitting defeat of the rear engine vehicle after ONLY 53 years in production.

I hate to say your prejudices are showing. A naval architect designs a boat, he actually spends time allocating the weights fore and aft and if a boat has the motor aft , designs the hull for that weight in that location.

Good design dictates that liquids are located near the fore and aft center of buoyancy so as water and fuel are used, trim remains the same. The engine is a fixed weight and can be allowed for in the design with other fixed weights balancing as necessary.

Since the vast majority of inboards are I/Os, it's hard to think they're all bad or poorly designed boats. You may really like you motor in the center of the boat. You may also like blondes. That's not to say redheads are diminished.

BTW, taking your car analogy further , most private planes have their motors in the bow. Should we therefore conclude that boats would be better with motors and props in the bow ?
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Old 11-11-2013, 07:18 PM   #33
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[QUOTE=manyboats;190898]Bob,
VW, Corvair, Tucker.

"Don't know about the Italian things but all rear engined cars seem to be a failure except the Porsche. And being German it dosn't need to be a design success."

Eric, I don't know what criterion you are using to describe the VW Beetle as a failure, they sold about 17 million cars worldwide, and had a production run of over 30 years.

They fitted their design/cost specification probably more effectively, than any other car ever manufactured, although you could put up an argument in favour of the Ford model T.

They managed to convey a personality, above and beyond their utilitarian roots, starting life providing affordable transport to Europeans after WW 2, to the becoming the face of the flower power revolution of the 60's, they made films, books and songs about them.We travelled the world in the Beetle's big brother, the Kombi. I went from London to Africa and back in my second hand Dutch ex postal Kombi van.

If that is not success then I don't know what is.

Edit;I should confess my first car was a Blue 1966, 1600cc Beetle, my dad took me to the car yard and the car dealer said to dad, when talking about the reliability of the Beetle,"these things almost won the war you know".
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Old 11-11-2013, 07:26 PM   #34
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While not a bad rule of thumb...it really does depend on how it's going to be used and how much you want to customize a drive train.
So true... So True! I should have added to my post YRMV!
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Old 11-11-2013, 07:33 PM   #35
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Porsche, Lamborgini, Ferrari?????
Ferarri and Lambos as well as Bugattis and Veyrons proudly proclaim "mid engine" as do the Toyota MR2 and Acura NSX if I'm not mistaken. Audi is even slipping mid engines into the fray
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Old 11-11-2013, 07:57 PM   #36
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Anyone that thinks adding a sterndrive to a boat has to balance it by adding weight foreward has NO CLUE about boat design.

Weight in a boat just has to be offset by buoyancy...no matter where you put that weight...if the hull shape has enough buoyancy to support it...it works...as long as the shape will conform to the original design requirements.

Some comments on this forum about boat design really scare me....

After getting all excited about I/Os I'm gonna bring up the bazillion designs that work just fine with engines in the cockpit with vee-drives...that ought to drive a few nuts around here....

The only thing worse than not knowing anything about boat design...is to try and compare boat design or marine engines with land counterparts...
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Old 11-11-2013, 10:55 PM   #37
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Dang it!!!!
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Old 11-11-2013, 11:03 PM   #38
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Anyone that thinks adding a sterndrive to a boat has to balance it by adding weight foreward has NO CLUE about boat design.

Weight in a boat just has to be offset by buoyancy...no matter where you put that weight...if the hull shape has enough buoyancy to support it...it works...as long as the shape will conform to the original design requirements.

Some comments on this forum about boat design really scare me....

After getting all excited about I/Os I'm gonna bring up the bazillion designs that work just fine with engines in the cockpit with vee-drives...that ought to drive a few nuts around here....

The only thing worse than not knowing anything about boat design...is to try and compare boat design or marine engines with land counterparts...

Well said!

Engine foward = slow boat
Engine aft = fast boat ( in most cases )
A really fast boat needs as much of the weight on the transom ..to get the hull out of the water
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Old 11-11-2013, 11:10 PM   #39
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Well said!

Engine foward = slow boat
Engine aft = fast boat ( in most cases )
A really fast boat needs as much of the weight on the transom ..to get the hull out of the water
Hollywood
Dat Y me 1975 Johnson 50 hp O/B on da 1975 Crestliner Stinger tow behind runabout do 39.5 knots at WOT wit jus moi aboard!?!? Und, 20 + nmpg at 25 knots with me and da Admiral aboard!?!?

Dat Said:

Our 21K lb gross 34' Tolly TC with twin screws and 2 - 100 gal gas tanks in center of boat planes off real fast and smoothly. Handles well and with 510 total HP hits 21/22 knots at WOT with an easy 16 to 17 knot sustained cruising plane... for traveling purposes (at 1 nmpg).
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Old 11-11-2013, 11:59 PM   #40
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Dat Y me 1975 Johnson 50 hp O/B on da 1975 Crestliner Stinger tow behind runabout do 39.5 knots at WOT wit jus moi aboard!?!? Und, 20 + nmpg at 25 knots with me and da Admiral aboard!?!?

Dat Said:

Our 21K lb gross 34' Tolly TC with twin screws and 2 - 100 gal gas tanks in center of boat planes off real fast and smoothly. Handles well and with 510 total HP hits 21/22 knots at WOT with an easy 16 to 17 knot sustained cruising plane... for traveling purposes (at 1 nmpg).
Art,
22kts is not a "fast" boat.

My SeaRay had 700+ hp, planed @19kts@ 3000rpm@..80 nmpg
WFO...30KTS@4200RPM = 60GPH..OUCH!

I love my mid engined 270hp diesel ...2.5gph@1700@8kts.
Our dinghy now has a 40hp ob, its a avon 3.10 sport boat rib..
Will do 40 topped and cruise at about 10nmpg

"Mid engine" boats, no matter how much hp top out at about 50mph, all the power is being used to lift the hull vs. provide foward movement.
The exception to the rule is the hydroplane..think back to the old rolls royce and allison piston hydros
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