Converting from I/O to V drive inboard

[F14CRAZY]

I'm tired of sterndrives. The Series 400 in my Capri isn't too far from shot. I re-sealed it before last season but ALL 4 compartments at the end of this season were somewhere between a milkeshake and creamed coffee. I pressure/vacuum tested too. I figured the ridges on the seal surfaces tore up the seals. I fix that I either need to pretty much rebuild the thing or use speedi-sleeves. Parts are kinda hard to get, everyone hates OMC stringer drives...so I got thinking about some better solution.

I thought about re-doing my transom to accommodate a Cobra but those aren't well liked either, with OMC being bankrupt and it seems you need micrometers to adjust the shift cables.

I'm open to other brands but I worked on my buddy's Mercruiser 283 and I personally think the gimbal bearing, U joint, and bellows is awfully hard to work on and not a good design. I assume that Volvo Penta drives are the same. Are these sterndrives of better build quality than OMC's?

I got thinking of how the V drive setup in my Coho is pretty straightforward and durable. Aside from the cutlass bearing, which doesn't contain oil anyway, there aren't any submerged components to take in water and burn up.

I've completely gutted my Bayliner and put in new stringers...how hard can it be? I've seen old wooden runabout projects with complete transmission and V drive systems for like $1k. If I have the complete drive and steering system how bad could it be? I think I'd just sell/scrap whatever Chevy V8 is included and find a decent 4.3L to use instead. Or find a Chris Craft/Paragon drive.

I figure the drivetrain could be mounted far back enough to not have to move the engine compartment forward, at least not much

Any objections?

 

[Bamaman1]

Re: Converting from I/O to V drive inboard

Do you think you'd be putting good money after bad? It'd be a large investment to put in a V-drive into the boat, and would it be worth it? You'd have to essentially buy an existing v-drive boat--and transplant the guts over to the Bayliner.

If you're wanting alternative power, it'd be easier to remove the I/O unit, glass up the holes and reinforce the transom. Then, you could come back with a fabricated external motor mount (aluminum) and a good used large 4 stroke outboard motor.

 

[Tahorover]

Re: Converting from I/O to V drive inboard

You would be better off just buying one. I picked up this Arabian for $1600:
http://www.youtube.com/watch?v=DyL7...xt=C3f86379UDOEgsToPDskL4f0xvHGzVqFuysKvXp9ZA

 

[86 century]

Re: Converting from I/O to V drive inboard

+1
All of the vdrives I have seen have a large flat area where the prop shaft goes though the hull.

 

[Don S]

Re: Converting from I/O to V drive inboard

You haven't priced Vdrives, shafts, props, packing glands, struts, hull changes and everything else involved in doing that changeover have you? The motor and vdrive will set higher and forward quite a bit, got room for all that?

 

[Part-time]

Re: Converting from I/O to V drive inboard

F14, I think your idea is cool!!
Not to start an argument but listening to some people all the guys from this thread would have been better off buying new boats http://forums.iboats.com/forumdisplay.php?f=407
If you know you have the skill to do it, go for it!
I took the 3.0 GM and 400 stringer out of my sea sprite deck boat and this spring I will be installing a 350 sbc and a jacuzzi wj jet (that I picked up from a guy that was converting his j-craft from a jet to a v-drive...)
Good luck and post lots of pics...

 

[Tahorover]

Re: Converting from I/O to V drive inboard

+1
All of the vdrives I have seen have a large flat area where the prop shaft goes though the hull.

Large?? 2-3" wide is the norm

 

[billbayliner]

Re: Converting from I/O to V drive inboard

Objections? No, it's your boat.
Your hull was designed for an I/O. I think that going shaft or V-drive, or even an outboard would create issues.

You mention that you're tired of I/O issues, everyone hates the OMC Stringer drive, you thought about the Cobra, but then about the OMC issues, the Gimbal system draw-backs, etc, then you ask if the Volvo is better built!
Not only is the Volvo Penta better built, IMO, but if you were to stay with an AQ series drive, you would not have any Gimbal system at all. All AQ series V/P's are main suspension fork and pivot tube geometry. All parts are available and will be for years.
This could be one of the later drives [up to 1996 in the AQ series] in either the single or Duo Prop. An SP C or a DP C for example. [not the SX or the DP-S. those are gimbal system drives]

If you went with the C or later [after the 290 style], you'd have no reverse latch that Volvo is notorious for having issues with, no rubber hub drive coupler, no annual engine alignment, no Gimbal Bell, no thru prop exhaust, no SI or ESA, just smooth cone clutch gear engagement, a good hydraulic trim system, very easy to work on, very easy drive shaft bellows replacement, no shift cable bellows, and so on.
The addition of the Duo Prop will give you a 25-35% performance increase which you probably don't need for a Capri boat.
The transom would need to be in filled and cut out for the larger foot print of the C or later V/P drive.
This would be less work than doing the shaft or V-drive and you'd have a trouble-free I/O that the boat was designed for.

Del shows the SP C style in the foreground here. This is what I'd recommend.
He shows the earlier SP to the right and rear. This one is similar to the 290 and will use the anchorage bracket and latch system.
If you went with the 290 style, you'll still have a good hydraulic trim drive and all other favorable aspects still apply.

 

[F14CRAZY]

Re: Converting from I/O to V drive inboard

Thanks for the replies. Perhaps the idea of changing to a V drive is a little outrageous. It isn't like it couldn't be done but the conversion wouldn't be that practical.

I personally feel that the OMC and Mercury stern drives I've messed with are compromised designs. The OMC has so many seals and compartments which probably weren't much of a problem when new but there's way too many places for water to leak in. I keep my Bayliner in a wet slip all season...if I was just running it for a few hours and trailering it each time I'd probably just keep changing the oil. When I had the thing torn down the dog clutch gears, the other gears, bearings, etc all looked good aside from the grooves where the seals ride. The water intrusion and operation during this past season probably didn't help though. It seems with my usage that I have to replace the ball gears every other season. It could be that the GLM ball gears aren't that good or that such a design that uses gears for power transmission without oil lubrication is just stupid. I suppose water lubricates, but if it really didn't, I wouldn't be worried about water in my sterndrive and intermediate housing. I know my unit could be rebuilt but I'm getting frustrated with the thing. I have a pretty good mechanical background and can follow the FSM but I'm not like a mechanic that's been working with these things when they were still being produced.

The Mercruiser 283 of my buddy's doesn't give me a good impression about Mercury designs either. He had me replace the bellows, gimbal bearing, and shift cable. I have small hands and found it a complete PITA to do and still a compromised design. The bellows design seems fragile and a leak trashes out the gimbal bearing and U joint all over again.

It's a shame that these things seem like they were engineered and produced in China but they came from the United States. Automotive engines and transmissions wouldn't have sealing surfaces that wear like this, or compromised designs (unless it's like, old British Leyland engineering or something). The engines themselves generally last a rather long time (sorry Mercury 3.7L owners) but to me the rest of the drive system sucks.

To me, the old Paragon transmission and V drive systems in my Chris Craft are lightyears better. The V drives don't seem to ever go bad unless they run out of oil and the transmissions are fairly easy to remove, rebuild, and reinstall. And rebuilds kits are still available for these things from the '60s. I know that Borg Warner Velvet Drives are even more durable than these. And the damn things aren't you know, underwater and vulnerable 24/7.

Are the components in Volvo Penta drives better to the extent that buying a used one should be ok? I don't mind spending money on my Bayliner...if I did I wouldn't have gutted the thing for new stringers etc, torn down the OMC drive, applied a barrier coat and bottom paint...I'm already in it now and acquiring another boat to replace it (aside from my Chris Craft, which is not a replacement) isn't something I'm really considering. Unless I were to buy a NEW boat I'd still be back to zero and have to worry about stringers, a bad transom, bla bla etc. I already know exactly what I have. I am open to picking up a "cheap" parts boat for the Volvo drivetrain and converting my Bayliner to accept it...I'm not afraid of glassing.

But with the work involved in reinforcing the transom, mounts, etc, I'd rather have a system that I'm personally confident in but getting it to fit may be too difficult. I haven't measured how long a Chevy V8 or 4.3L V6 with a transmission and V drive is and have not considered other engineering that is beyond my skills such as the driveshaft angle.

So yeah...apologies for this sounding like a rant but its quite frustrating

 

[Bondo]

Re: Converting from I/O to V drive inboard

The Mercruiser 283 of my buddy's doesn't give me a good impression about Mercury designs either. He had me replace the bellows, gimbal bearing, and shift cable. I have small hands and found it a complete PITA to do and still a compromised design. The bellows design seems fragile and a leak trashes out the gimbal bearing and U joint all over again.

Ayuh,.... Considerin' the 283 ain't been built since 1967, 'n Mercruiser didn't use 'em....

It's pretty hard to say just which antique drive yer lookin' at....

Life is full of compromises...
The Merc drives are well proven, with BaZillions of hours behind 'em....

At this point in history, Mercruiser is the only answer is Money is a consideration,...
They've had the Major Market share for Soooo long, that new/ used/ rebuilt parts are nearly a Dime a Dozen, 'n can be found most Anywhere at the corner 7/ 11 convenience store marina...

 

[F14CRAZY]

Re: Converting from I/O to V drive inboard

My bad I think I meant 277...? It's behind a Ford 351

 

[Part-time]

Re: Converting from I/O to V drive inboard

Your hull was designed for an I/O. I think that going shaft or V-drive, or even an outboard would create issues.

So this boat was desinged to be a V-drive...

You would be better off just buying one. I picked up this Arabian for $1600:
http://www.youtube.com/watch?v=DyL7...xt=C3f86379UDOEgsToPDskL4f0xvHGzVqFuysKvXp9ZA

I wonder if Century knows that.... they put a mercruiser in mine.

Even a dfiferent style outdrive, different motor will make a boat behave differently but it doesn't mean it's a bad thing and shouldn't be done.
Sidewinders used the same hull for outboards, I/O and jet drives, all very good handling boats.

 

[Tahorover]

Re: Converting from I/O to V drive inboard

So this boat was desinged to be a V-drive...


I wonder if Century knows that.... they put a mercruiser in mine.

Even a dfiferent style outdrive, different motor will make a boat behave differently but it doesn't mean it's a bad thing and shouldn't be done.
Sidewinders used the same hull for outboards, I/O and jet drives, all very good handling boats.

Sorry.

 

[Part-time]

Re: Converting from I/O to V drive inboard

Sorry.

Sorry for what?
I was just stating that your boat came with an inboard and my pretty much identical boat came with an I/O.
And if I recall yours has a big block chrysler and mine has a small block chevy.
Manufacturers will often use the same hull with several very different propultion systems so why should someone be so quik to say it won't work for a guy like me and you to do the swap.

 

[Tail_Gunner]

Re: Converting from I/O to V drive inboard

As Don illuminated there would be a great deal of work to be done..And a great deal of structual work...We have a member Ondarvr who has a vst amount of mfg knowledge in boats..you might Pm him..The boats balance would be badly affected....

Now with that in mind do the research and tinker to your hearts content...That is what this forum is all about.......We have one member who cut his boat in half..so don's think its impossible that memeber did a stand up job..

 

[billbayliner]

Re: Converting from I/O to V drive inboard

The V/P drive won't spare you from bellows failure, but the AQ series bellows are much easier to replace than on the Gimbal system drives.

As for the I/O vs I/B I'd think that the propulsion from an I/O should be favorable.

Buying a good used V/P drive is OK. You may want to reseal it, but you should not have any issues.

True, Merc has had a major market share for years. But look at the used market. The market is strong for good used Merc and OMC parts.
Volvos rarely wear out, so the market is soft on good used V/P parts due to the boats failing before the running gear fails. Supply/demand!

Until you get into the B series Merc, all but the TR and TRS are all Dog Clutch gear engagement.
The Merc B series uses Volvo Penta's patented cone clutch gear engagement design.

 

[Don S]

Re: Converting from I/O to V drive inboard

I gathered up some vdrive drawings and sterndrive drawings, put them together and adjusted, just to see where the engine would have to set. For a standard 12? down angle for the vdrive, and for you to swing a 14" prop, with about 8" of room behind the prop for the rudder to come through, you would need to move the engine up an inch or two, but you would need to move the engine forward about 34 to 36 inches.

Here you can see my sketchings, the blue is the hull, the green is the prop, black outline is the vdrive and engine.

 

[F14CRAZY]

Re: Converting from I/O to V drive inboard

wow thanks Don S...yea sadly while I don't mind opening up the rear of the cockpit, an engine right in the middle wouldn't be desirable. There just isn't enough room in this hull design.

Back to Volvos...

 

[Don S]

Re: Converting from I/O to V drive inboard

The newer Volvos, SX/DPS (94-06) style, do have the gimbal bearing, but the bellows can be changed in about half an hour to 45 minutes. Including pulling the drive and putting it back on. Merc does make that a real job in the older (90 and earlier) drives. The Gen II ujont bellows aren't bad either.
The bellows on the SX style Volvo and the Merc Gen II or Bravo drives are good for about 5 or 6 years, even in salt water. The older Volvos like billbayliner talks about have thinner bellows and only good for a couple of years max in salt water. If they leak, and water gets into the flywheel cover bearings (PDS bearings) pulling the engine for repair is necessary. But, changing the bellows is also easy and not a real concern.
Personally, I wouldn't have anything but a Volvo, but, Merc parts and new drives are going to be a LOT less expensive and easier to come by than Volvo.
No matter what outdrive you end up with, pulling the outdrives every year is going to be a must.

 

[F14CRAZY]

Re: Converting from I/O to V drive inboard

What needs to be serviced every season? Seals?