B25 WHAT IS BEST ENGINE AND DRIVE TYPE

joelmcquen · Post by **joelmcquen** » Mar 12th, '07, 12:56

OK GUYS I KNOW IT IS A 25 BUT I JUST BOUGHT A 1968 HARD TOP TWIN IN BOARD and i need your input about where to go inboard. I/O vdrive. or jet .diesel .or gas .need very good fuel economy but cant give up good cruise speed my first idea is single diesel with jack shafted volvo duo prop scond would be twin 4 cyl diesel inboard ( the esay way ) have thought about jet drive but have no experience with jet . AND NO I WILL NEVER SELL MY 31 all of you guys have been a best source of info in the past HELP!!!!!

randall · Post by **randall** » Mar 12th, '07, 15:28

personally i think twin 4 cylinder diesels is the way to go with inboards if you have the green....post on the 25 site and you will get 25 answers........as far as gassers go looks to me like kelly has the best set up 350 chevy, i think........me ...im runnin 1984 chrysler 360's....till they die

mike ohlstein · Post by **mike ohlstein** » Mar 12th, '07, 15:32

John Cranston's 170 Yanmars might be nice......

Rocket · Post by **Rocket** » Mar 12th, '07, 17:13

Single Volvo D6, jackshaft XDP duoprop outdrive would be an amazing combo in this boat.

randall · Post by **randall** » Mar 12th, '07, 17:58

2 engines you infidel....no hall pass for you......

randall · Post by **randall** » Mar 12th, '07, 17:59

would those 170's fit.........oh no ,yannmar envy!!

Rocket · Post by **Rocket** » Mar 13th, '07, 11:31

Randall - apparantly you haven't heard my big single diesel for speed and economy and genset plus twin electric trolling motors mounted under the swim grid for docking and limp-home theory...but that's just crazy...I await the slings and arrows!

randall · Post by **randall** » Mar 13th, '07, 11:44

far from the worst idea i ever heard.....i just kiddin around...hell...vic thinks its sacralige to paint the hull anything but white

Capt. Mike Holmes · Post by **Capt. Mike Holmes** » Mar 13th, '07, 11:49

There is a 25 listed for sale in the Freeport, TX, paper with a single Volvo diesel - for $10,000, with trailer.

Rawleigh · Post by **Rawleigh** » Mar 13th, '07, 11:55

It might be an interesting application for Mastry's geared drive splitter. Single engine but twin drives. Go with a Steyr with the generator attachment in the bellhousing.

Rocket · Post by **Rocket** » Mar 13th, '07, 12:01

Rawleigh, have you got a website for the gear splitter? - that is another idea that has been rattling around in my tiny little brain - be a cool way to repower a v-drive boat utilizing the existing running gear. the gear splitter would act as a torque divider and coupled with a highspeed diesel you could use the same stuff. Might get a little tricky from a geometry/fabrication point of view, but it would be cool. One would not lose the drag from the second set of strut/shaft assembly, though.

In Memory of Vicroy · Post by **In Memory of Vicroy** » Mar 13th, '07, 14:13

White hulls for sure, unless at the TSL, otherwise you'd never figure out which boat to get on......

The drivesplitter rivals the IPS (and casinos) on top of the list on how to separate fools & their money.

UV

Hyena Love · Post by **Hyena Love** » Mar 13th, '07, 17:42

How does one run a single engine inboard boat with a v-hull? Now, I can see how it might work with an outdrive, but for an inboard, that prop is going to be hanging real low, have a big prop pocket, have a huge shaft angle, or be past the transom, right? Am I missing something here?

Rocket · Post by **Rocket** » Mar 13th, '07, 17:50

UV - I know about your objections on the IPS, but was curious what the knock on splitters is - I have some ideas of downsides, but nothing that can rival the power of a VLT to take one's money!

Hyena - they are like regular shafts they just come out the very bottom of the "V" way, way deep unless you install a prop pocket like Scot is doing. Sometimes the rudder gets hung off the transom like in the old Donzis

Rawleigh · Post by **Rawleigh** » Mar 13th, '07, 17:57

I don't have the website, but Mastry Ensine Center had it at the Miami Boat Show. Nice looking piece! Call them.

http://www.mastry.com/

In Memory of Vicroy · Post by **In Memory of Vicroy** » Mar 13th, '07, 19:39

Rocket - my knock on the geared splitter is you cannot vary the rpm between the props. About 38 years ago I bought a 1947 45' cypress cabin cruiser, oddly enough, named the "Rocket", that had a pair of Chrysler straight 8 army tank engines. The old engineer guy I bought her from had designed a hyd. system to run her off one 6-71 DD. His system had the 6-71 running a big hyd pump and a hyd motor running each shaft. He had a fairly simple throttle valve arrangement to allow you to run the props in any direction at any speed, each independent of the other. As it turned out, the old straight 8s ran for as long as I had her, sold her to our local coroner about 30+ years ago, and she's still on the Tickfaw River running with the same WW2 army tank motors. But the hyd option is a viable one in my view - all off-the-shelf parts, and you could plumb the hyd motors, which are very small, very far forward in the boat and have about any shaft angle you want.

UV, a firm believer there are more ways to skin a cat than feed it melted butter......

randall · Post by **randall** » Mar 13th, '07, 20:13

rocket.....im with UV on this one...no point in havin 2 engines (or 2 props) if you cant vary speed and direction......i ran the boat a whole season with no steering and no reverse on the port engine...really not so bad with twins....why put all that extra drag under the boat?...all pain no gain....now one big diesel....not my cup of tea but makes sense....my favorite is a local downeaster with external under hull heat exchanger and a dry stack...nothing touches salt water...no holes

In Memory of Vicroy · Post by **In Memory of Vicroy** » Mar 13th, '07, 20:28

Randall, for commercial boats, the keel coolers are the cooling system of choice down here where we have a lot of shallow water, and big stainless props in Kort nozzles for the tugs. All dry stack. When the Port Eads harbor would silt up, Buzzy would call one of his buddies with a 3,000 hp tug to come "blow it out". They would ease in the cut, feel the bottom, mosey around, then put all the hp to work, just amazing how fast they could cut a channel, just pure horsepower and a skilled coonass at the controls.

Anyway, all the really big oilfield supply boats now are diesel-electric, several big diesels running DC generators that feed electric motors on the shafts, pure variable drive. Not feasible on a small boat, but the same principle as a hyd drive that probably is.

UV

Rawleigh · Post by **Rawleigh** » Mar 14th, '07, 08:17

UV: I have to agree with you. You could shift them with a set of gears on each side after the splitter, but couldn't throttle them idependently. I too have wondered why no one has tried the hydraulic option. I don't know what the power lose factor would be, but a single big diesel would be nice. It works 24/7 on heavy equipment and lasts for 10k + hours. I also agree with Randall about the keel coolers. We used to make them for workboats out of galvanized plumbing parts (back when there used to be watermen around here). Put a zinc on them and they last forever. Unfortunately we get arrested around here for "prop dredging". Have to do it while "working" on the engines at night!

Capt. Mike Holmes · Post by **Capt. Mike Holmes** » Mar 14th, '07, 08:27

Randal, with the Mastry system, there are two transmissions running off one engine. Like Vic said, you can't vary rpm from one side to the other, BUT, you can have one in neutral, or one in forward, the other in reverse. This at least allows some of the advantages of a twin engine boat, for docking and steerage. I think their tests also showed improved performance with two props versus a single. It's not as good an idea as Vic's hydraulic system, but it's a start to improving single engine performance. Also, it solves the problem of how to rig a single engine inboard in a deep vee hull.

randall · Post by **randall** » Mar 14th, '07, 08:49

i think a prop pocket is a better solution only cause i like to keep stuff as simple as possible...best design...surfboard......no moving parts.....56 austin healey....dosent even have exterior door handles.....boats are complicated enough .(or i'm just lazy)......maybe its why i like sailboats..........................................the keel cooler guys love when the bay ices up...say it scrapes all the growth off

CMP · Post by **CMP** » Mar 14th, '07, 10:20

Randall needs a pair of D3 190's. I wish I was more ambitious and went for the v-drive set up he has...

CMP

randall · Post by **randall** » Mar 14th, '07, 10:25

mark.....its only a matter of $$$$...right now its a contest between which will last longer...the toyota or the chryslers

CMP · Post by **CMP** » Mar 14th, '07, 12:07

My money's on the Toyota...

CMP

Eddy G · Post by **Eddy G** » Mar 14th, '07, 13:40

Vic, I didn't know you were the previous owner of Hypolite's Moon River. What a great boat! It really fits the scene here in south Louisiana. Did I read in a previous post that you and some others here were attending the St. Pat's Parade? If so, where are ya'll drinking?
Eddy G.

randall · Post by **randall** » Mar 14th, '07, 15:07

well to be honest the chryslers though older get far better care...the toyota has had a partially blown head gasket for the last 5 years..refill the coolant tank every two weeks...it runs on old boat spark plugs that in no way relate to the engine except they free and fit in the holes....starts on one or two cylinders and after bout 20 seconds the other two chime in......muffler fell off 6 months ago but the cat converter damps the sound some....been years since my wife would ride in it............pretty girl comes up to me in a bar and says..."i know you, you drive that incredibly beat up black truck"

CMP · Post by **CMP** » Mar 15th, '07, 10:04

Ahhh, so you kee the 'Yot 'cuz it's a chick magnet! I see how it is!!!

CMP

Doug Crowther · Post by **Doug Crowther** » Mar 15th, '07, 11:21

Mark,
Hope your project got off to the painter on schedule. Any sign of my rldt window frames from Timmy for powder coating ? Oh, and there is a corner that needs one of your perfect welds.
Doug

randall · Post by **randall** » Mar 15th, '07, 11:29

well..... in a town where among a certain (large) segment of the population image,the appearence of financial success and celebrity are paramount.....it does make a statement........

bertram31.com

B25 WHAT IS BEST ENGINE AND DRIVE TYPE

B25 WHAT IS BEST ENGINE AND DRIVE TYPE

25

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