Volvo/Penta-280dp diesel conversion question

[sailinphelan]

I have a V/P280 dual prop in a houseboat with a 302 V8, I want to put a small diesel in it. Is there a diesel that will bolt up to the Volvo drive? This is an early 70s drive, and I know they had Volvo diesels, but I am not sure what engine they were based on.

a small 4 cyl. would be fine with me, all I want to do is chug along slowly.

I know I will need larger props for the low rpm, but for now, I am trying to figure out what make engine might bolt up by possibly just changing the intermediate housing.

Any suggestions would be appreciated.

Thanks, PJ

[2850 Bounty]

PJ, Your concern is legit, but does come with a price.
Volvo does offer a small Diesel that can be made to work in this hull, but your drive ratio is incorrect for this.
More than meets the eye would require changing out.

Some other small Diesels can also be made to work since the AQ series Volvo Penta can be used with the Borg Warner adapter (such as your 302 Ford uses) for the transom shield and drive connection.
Now you must deal with exhaust issues!

Even if going with the little V/P OHC 4 would require some changes.
BTW, that would be a very good choice, but still..... it requires these changes.

I think it would take a tremendous amount of usage and fuel consumption to re-coop the cost of the conversion.

What is your reasoning other than a maybe fuel savings if you are simply putting around?

Rick

[CDK]

Sailinphelan says he wants to chug along slowly, so the current gear ratio is perfect for his purpose.
A marinized 2.5 Ford Transit engine with a B/W adapter would be a good choice.

Lancingmarine.com is the site for such projects.

[sailinphelan]

I have two main reasons, fuel consumption being a big one, the other one is that I am not fond of carrying around large quantities of gasoline on a boat with old hoses, lines, pumps, filters, wires, etc. just the fire hazard is a problem. In addition, the gas that is available now in Florida all has methanol in it, and it is eating up all sorts of rubber components on older engines. I have had problems now with 3 older units that I run.
But, mainly the fire hazard and the reliability of diesel (I know I mentioned a small gas engine, but now I am only considering diesels).

There are several small diesels I have located, I am just trying to find out what kind of bellhousing adapters there might be available before I buy the engine.

Thanks for the input,
sailinphelan

[2850 Bounty]

sailinphelan,
I certainly understand your reasoning. I also and certainly know that the return on an expense, such as this, will be little to non existent. And, unless using the Volvo diesel, you will have exhaust routing issues unless you go thru the transom.

As for your concern about gasoline on board..... understood!
However, consider that there are still approximately 100 to 150 boats out there in the world still using gasoline and with gasoline fuel tanks, gasoline fuel fills, fuel tank vent lines and engine fuel lines with gasoline fuel delivery systems at the engine......., my boat being one of them!
(yes, a sarcastic but friendly response to make a point)

The point re methanol in Florida's fuel and of the rubber components can mostly and easily be resolved these days. (I think that 14 of the above mentioned boats reside in Florida.) (I know, more sarcasm!)

I'm certainly not suggesting to Not Do This, I'm just bringing up some "food for thought" for you.


As for adaptation....... what you are calling a "Bell Housing" is a "Flywheel Cover" in the marine world.
The B/W pattern Flwheel Covers and adapters are used throughout the Marine Industry..... the Volvo Penta I/O adapter, the Borg Warner, Paragon, Hurth, even Volvo's I/B transmissions, etc ....... and these can almost certainly be adapted to many engines whereby a B/W flywheel cover had been manufactured and can be obtained.
You will be limited to engines that are more commonly used in a marine application. If not commonly used, I doubt if you'll find a B/W type flywheel cover for that engine...... hence, a very difficult time with connecting to a Volvo Penta I/O of the AQ series.

NOTES:
The V/P AQ series sinlge exhaust relief transom shield "exhaust down tube" is for a Stbd exhaust engine.
The gear ratio needs to be for the diesel..... (I know you only want to only chug along).
The change to an "over-all" gear ratio occurs in the lower unit..... not in the transmission (upper unit).
You'll need one of the Volvo Penta B/W I/O adapter housings....... (a Volvo Penta B/W pattern "Primary Drive Shaft" housing to be exact).
On that note..... you'll find the short Volvo Penta B/W adapter (standard v/p i/o offset) and you'll find the older, but approximately 3" longer, "Holman Moody" type (and a few others from the old days).

I happen to have one of the H/M extended units should you need one.

Don't get me wrong here...... I love a project...... I've taken on similar projects ......... and I'd be one of the first on board to help if I were your neighbor, for example.

Good luck with this. I'll stay tuned here and occasionally check in.

[sailinphelan]

Thanks for the input. As you can see, I am more familiar with hot-rods than Stern drives. Help me understand and correct me if needed. The flywheel cover that I now have, on my 351, probably goes from the Ford engine to a B/W pattern; then the adapter, or intermediate housing that I have, goes from the B/W to the Volvo Penta trans/outdrive. Do I have that right?

That being the case, I could use any engine I could find a B/W flywheel cover for right?

I understand the problem with gear ratios, I would use a smaller diesel engine if I change it, so it might ultimately work out, since I probably won't have the HP to turn the props the original rpm anyway.

[2850 Bounty]

Thanks for the input. As you can see, I am more familiar with hot-rods than Stern drives. Help me understand and correct me if needed. (1) The flywheel cover that I now have, on my 351, probably goes from the Ford engine to a B/W pattern; (2) then the adapter, or intermediate housing that I have, goes from the B/W to the Volvo Penta trans/outdrive. Do I have that right?

That being the case, I could use any engine I could find a B/W flywheel cover for right?

I understand the problem with gear ratios, I would use a smaller diesel engine if I change it, so it might ultimately work out, since I probably won't have the HP to turn the props the original rpm anyway.Many gas and diesel engines will have the ability for a Marine "Borg Warner" bolt pattern flywheel cover. The Borg Warner "drive couplers" are also very common.
This allows the use of many I/B transmissions, jet drives and the Volvo Penta I/O Primary Drive Shaft Housing........ I.E.; what the AQ series out drive "Transmission" connects up to.


(1) Yes, the Ford B/W flywheel cover is connected to the Volvo out drive via a B/W pattern adapter. (Primary Drive Shaft housing)

(2) Well, it is called a "Primary Drive Shaft Housing! The B/W is the bolt pattern. In this scenario, it allows for a Volvo Penta primary drive shaft housing that connects the Volvo Penta transom Shield. (I think what you are calling the intermediate.)

Volvo did have their own B/W flywheel cover/adapter on the old AQ 200A. There were also some not manufactured by Volvo..... (The Ford PDS, for example was often Glastron or Eaton or whoever marinized the package.)

The only remaining issue with not using the Volvo Penta engine, or one of the engines that were used (GM, Ford, Chrysler) would be the exhaust system.

I was instrumental in helping a man convert a 460 King Cobra to an AQ series Volvo Penta DP C drive. He located a 460 B/W flywheel cover..... and the rest was easy.

[CDK]

Thanks for the input.

That being the case, I could use any engine I could find a B/W flywheel cover for right?



You could also use any other engine for which there exists no Borg-Warner cover. Making an adapter housing is no big deal, it is just a passive component with some holes in the right places.
Much more important in my opinion is the availability of the water jacketed exhaust parts because these are not so easily (diy) made.

[2850 Bounty]

You could also use any other engine for which there exists no Borg-Warner cover. Making an adapter housing is no big deal, it is just a passive component with some holes in the right places.
Much more important in my opinion is the availability of the water jacketed exhaust parts because these are not so easily (diy) made.Something to consider: Most any automotive or industrial engine that would be considered a good marine performer, most likely has a B/W flywheel cover in existance for it.
Conversely, I doubt you'll find (nor want to make one) for an engine that does not work well in a Marine application.

The B/W type F/C's also incorporate a precise dimension for the flwheel surface to B/W surface.
This is due to the Borg Warner spline "Drive Coupler" being in the precise location for the use of the B/W spline transmission shafts: Paragon, B/W, Hurth, Volvo, etc.
All must work together and with interchangeability.

And yes, while I think the engine cooling design would be an easy task, I agree w/ CDK...... one of the issues is still te exhaust system. The exhaust, whether the engine is naturally asperated or is Turbo Charged, now must be designed to work with the potential back pressure of a wet exhaust system.
The greater the work load, the greater need for THIS system to work proplerly

There is quite a bit to this, as I am sure you are aware....... we don't just grab an engine and adapt things!

.

[sailinphelan]

I realized the problems with the exhaust early on. I am looking for a small marine diesel, it just seems most of them bolt directly to transmissions, so I wanted to make see what it would take to bolt it to the Volvo/Penta outdrive.

One issue with the engine I now have that started this entire process is that the previous owner recently changed the engine and apparently didn't torque the flywheel; which now appears to have loosened up. I don't know how much damage it has done, it was loose when I got it, with a major vibration. Now I realize there is some chance that something else is causing the vibration, but it is really bad. The neighbors tell me he never took the boat out after the swap, so maybe the damage isn't that bad; but if the crank is damaged, then I would proceed with the diesel swap for sure.

[2850 Bounty]

I realized the problems with the exhaust early on. I am looking for a small marine diesel, it just seems most of them bolt directly to transmissions, so I wanted to make see what it would take to bolt it to the Volvo/Penta outdrive.

One issue with the engine I now have that started this entire process is that the previous owner recently changed the engine and apparently didn't torque the flywheel; which now appears to have loosened up. I don't know how much damage it has done, it was loose when I got it, with a major vibration. Now I realize there is some chance that something else is causing the vibration, but it is really bad. The neighbors tell me he never took the boat out after the swap, so maybe the damage isn't that bad; but if the crank is damaged, then I would proceed with the diesel swap for sure.Look, there are an array of Primary Drive Shaft houings that will work with the Volvo Penta. That is what I've been saying here.
I have thedr if you can't find one. They all interchange, with exception to the two lengths that can be found. I have both.

Now, if the "Primary Drive Shaft" bearings are gone (very common by the way), then there is a potential for a large vibration......, a vibration that will soon turn into a greater expense if you continue to use it.

So, loose flywheel or bad PDS bearings...... it needs to be torn down and examined and repaired.
Bearings/seals for this are very cheap..... you need not buy through Volvo Penta.
These are a standard bearing and the seal can easily be cross referrenced.
I have these too.

Hope that helps!

.

[sailinphelan]

Thanks bounty,
I will pull it out and see what the deal is. From some of the other things I found (eg. he left the main jets out of the carb. and was trying to run it that way, and the engine was filled with ATF) I wouldn't be surprised if he didn't tighten the flywheel, but I will be sure to check the bearings as well.
I will let you know what I find.

[CDK]

This story is getting more and more interesting. What other surprises may the previous owner have tucked away for you?

I once owned a beautiful Rover 2600 with automatic gearbox. There was a vacuum activated device that determined the gear change thresholds. But the membrane ruptured and the engine sucked the gearbox dry while filling itself to the brim with ATF. The whole process took no more than 300 miles and ended in a total loss...

[sailinphelan]

I pulled the engine, and in the process found the engine beds were bad, and the mounts were badly adjusted. The engine was in a terrible bind. Once out, I torqued the flywheel and drive plate. No obvious problem with the flywheel which I had feared, having had that problem before with a similar vibration. The drive plate was not tight, but no damage and not the source of the vibration. Once re-bedded and aligned, I fired it up and took it out for a spin, well not a spin, more of a puddle along since it wasn't completely bolted down as it should be, and the epoxy probably wasn't completely set up, but it did fine. The vibration was gone! Apparently a result of engine alignment and sitting hard on the mounts.

So far, I have replaced the exhaust hoses and the elbows on both sides. It has a bad oil leak at the front seal, and the outdrive was leaking a little 90wt. into the bellhousing, I mean scatter-shield, I mean flywheel cover!!! Too many under the hood of hot-rods. I also suspect leaking exhaust manifolds.

BTW, speaking of Rovers, I currently have 3 Land Rovers, 1960,61,73. Ser 1,2 and 3. (I don't know why)

PJ

[sailinphelan]

So now my dilemma, do I continue to repair the old V8, new manifolds, front pulley and seal, fuel pump, and unknown others, or do I dive into diesel?

[sailinphelan]

I found a couple of Perkins diesels, and bought both of them. I have a 4-108 and a 4-107, not much difference, both have transmissions, but I won't be using them.

I moved the boat from Lake Kissimmee to the St. John's near Palatka, and we have ran it a little. It seems the Ford 351 probably has the harmonic balancer and pulley off of the 302 it came with. It still has some vibration, but doesn't smoke and after some carb work, it actually runs very well.

I am going to tune up the diesels (Westerbeke Marine) and after they are running well, make the swap.

I run the gas motor at around 2500 rpm and the boat goes the speed I want to go with the diesel, so the gearing will probably work ok.

Somewhere in the process, I lost the small prop of the two, it just came off. I hadn't had it out, so I don't know what was loose, no telling. I am wondering if I could go up slightly in pitch, realizing at the same time, that I can't make up gearing with pitch without loosing torque, another boat quandary.

PJ