Logo
FULL SITE MENU

OMC to Volvo Penta DP-SM conversion

S

Star

Member
I have a 1991 Chris Craft with a 351 Ford coupled to an OMC sterndrive. I can get a VP DP-SM for cheap. I know this topix has been covered a few times, but after reading a couple posts from years ago, I'm unclear if there is any conversion kit needed other than changing the cable and the raw water pump. My question is, what is actually needed to do the conversion? Thanks, this is a very valuable forum!
 
Yes, there is a kit available if you are doing an OMC Cobra-to-Volvo Penta SX or DP-S conversion.
If you install all of the SX or DP-S components, no kit is required.

I do the AQ series primarily, but if doing a kit conversion, the Gimbal Bell must be changed and I believe that a spacer is added to each hydraulic cylinder.
You'll be able to do away with the OMC ESA system completely.
The shift cable can now be extended and make a direct connection to the drive.

The OMC drive seawater pump will now be gone, in lieu of an engine mounted seawater pump (V/P has never used a drive located seawater pump).



The DP-S props are unique in that the prop set is thru-hub-exhaust.
Prop as you would with any single prop drive by observing your OEM WOT RPM specs.



You'll now have smooth cone clutch gear engagement, and the Duo Prop thrust will amaze you. :D


.
 
Richard,

I was hoping you would respond as you seem to be the expert in this. Is the Gimbal bell the part that swivels from port to starboard? Or is it the part that the outdrive itself is bolted to?

Thank you again for your response!
 
Star said:
Is the Gimbal bell the part that swivels from port to starboard? Or is it the part that the outdrive itself is bolted to?
Click to expand...
The part that allows for Port/Starboard articulation would be the Gimbal Ring.

What I'm calling the "gimbal bell", others may be calling a "pivot housing".

This part is suspended within the gimbal ring and allows for the Up/Down articulation.

(Cobra bell)

mtFt-ELkFNa7F8WBfY-3hZw.jpg



In order to adapt the SX or DP-S drive, this housing is replaced with the Kit part.

BTW, you may want to double check as to which drive is a candidate for the conversion.
I know that the DP-S is, but I'm not sure if the DP-SM is.



.
 
Ricardo,

Is the DP-SM drive identified by the exhaust going through it's own housing?

I have the entire outdrive and transom shield for the DP-SM. It looks like changng the bell will do the trick. I can't find the kit you refer to. That may be the biggest help in this changeover.

Thanks
 
The drives that I'm familiar with that work for this conversion, would be the SX and DP-S.

Star said:
Ricardo,
Is the DP-SM drive identified by the exhaust going through it's own housing?
What we call the AQ series (main suspension fork and pivot tube geometry) exhausted through the housing above the propeller area.
The later Volvo Penta (Gimbal suspension drives) (SX and DP-S style) use Thru-Prop exhaust.


I have the entire outdrive and transom shield for the DP-SM.
It looks like changng the bell will do the trick. I can't find the kit you refer to. That may be the biggest help in this changeover.
I'd be inclined to use all of the Volvo Penta components. This would save you from buying the kit.

Thanks
Click to expand...
 
Ricardo,

Do you have a link to the kit? I've searched but I can't find it.

AND thank you for taking the time to respond to all of the post that you do!
 
Star said:
Ricardo,

Do you have a link to the kit? I've searched but I can't find it.

AND thank you for taking the time to respond to all of the post that you do!
Click to expand...
Sorry.... I do not.
Just do an extensive search... Im sure that you can find one.

I think that the kit runs around $800 - $900 or so.
If you have all of the Volvo Penta DP-S components... why not use them in lieu of the kit, and spare the cost?


.
 
Invoke the "advanced" feature.
Click on the paper clip icon for attachments.
Next click on "add files".
Next click on "brouse".
Once you locate the image in your files, high-light it.
Click "open".
Next click on "Up-load".
Finally.... click on "done".

Your image should now be viewable for us.


If your image is hosted elsewhere... simply post a hyperlink to it.


.
 
If I may; The M in SM is a model change/upgrade number.IOW first there was the DP-S, then the DP-S1 then the DP-SM. Everything is compatable with the VP gimbal drive from DP-S through DP-SM. If you have the complete Volvo Penta setup including the inner transom mount, you are golden and have no need for any kit. The mounting holes are the same for the OMC Cobra and the Volvo Penta SX-M.

Hope this helps!
 
Thanks or the info Fish-a-Polooza.

Here is the only issue I have and the reason I want to know if the OMC and DP-SM inner transom mount are the same:
photo3.jpg
The donor boat was in a fire while the boat was in the water.
The entire inside of the boat was burnt.
The outdrive was under water and in in perfect condition.
The Volvo inner tramsom plate got hot. How hot, I don't know.


So, since I can't be sure about the integrity of the inner plate, I'm trying to find it the OMC and Volvo are the same.

Can you tell me a good site to look up these part numbers?

I want to thank everyone for the responses. This site is full of knowledgeable people and everyone seems to stay on topic. :)
 
Just use a wire brush, a little SOS pad and Ajax, JB Weld, and you'll be Good-to-Go! :D


As for the OMC inner transom plate fitting and working with the Volvo Penta DP-SM transom shield..... all you can do is give it a try.
If it will not work, find the correct one on e-Bay or _____ !

If the conversion kit runs near $800+ or so, and if you can forego using the kit (minus the engine mounted seawater pump), you've got that same $800+ to work with.

I still prefer the idea of using "ALL" Volvo Penta OEM parts for your conversion.



.
 
Last edited:
LOL Ricardo!

I bought the donor at auction for $125. Since it came with the toasted motor, I also have the raw water pump. It should be ok since it is brass and was low in the fire and away from the hottest part. Maybe I should say, mabye the pump is ok. :) I still need the 33C cable from what I've read.

I will post a picture of the inner tramsom plate when I remove it. However, that will be a while as this will be a winter project.
 
The inner transom plate from an OMC will not work. I just did this about 3 weeks ago; meaning I converted an OMC Cobra 3.0L to a 4.3L Volvo Penta DP-S1, including VP gimbal housing and bell. I realize your currently a Ford V-8, but as for what I'm refering to it won't matter the make of gas engine.

When I installed my OMC inner plate I realized there is no hole to run the shift cable through. The first thing I thought of was modifying it. Cutting a hole would be a major PIA due to where you would need to cut. I looked on E-bay and found a Volvo penta SX-M inner for $45.00 shipped. Since this is a winter project you have lots of time to be patient and find a good price. That said the only things that should be a problem from fire is the cable sheath and the rubber in the rear mounts, again, very cheap to aquire on e-bay.

As far as the 33c cables goes, I removed the red OMC cable ends, attached VP brass fittings, and I was able to use both cables; including eliminating the entire ESA, brackets and all, and running the original shift cable coming from the controls directly to the VP shift plate. I don't know how your controls are set up, I assume its' similar to what mine was, in that the throttle cable for the OMC pushes and the VP pulls so you have to take the controls apart and change it around.

In the end the only items that remain OMC on my change over is the engine coupler, the flywheel cover, and the trim/tilt system.
 
Last edited:
.................
Star said:
LOL Ricardo!
So........ the wire brush, SOS, Ajax, JB Weld and clean-up is not a good idea? :D

I bought the donor at auction for $125.
Wow... Even with disposal costs...... you stole that DP drive.

I still need the 33C cable from what I've read.
Yes.... the Morse or Teleflex 33C. You'll now have 1 main shift cable only, and it will be much longer.

And as Wayne said.... you get to eliminate the ESA entirely. That alone will make this conversion well worth doing.
The added thrust from the DP will amaze you.

Click to expand...


.
 
Last edited:
One more thought, and maybe I just missed this; the donor boat has/had a V-8 correct? If it was a V-6 the drive ratio may be wrong. What does the side plate indicate for drive ratio?
 
That is the only area that I'm a little concerned. It is a V8 and the ration is 1.95. This, to me, sounds like it is a little high. What do you think?
 
Ricardo,

Yes, I stole it and it cost 50.00 to dispose it. :)
Eliminating the ESA is a hugh plus. I just started having problems with it two months ago.
 
Is there a site to cross reference part numbers or to look up parts by year? Either for the Volvo or OMC? I can find some of them, but the transom mount is where I come up against a wall.
 
Is there a site to cross reference part numbers or to look up parts by year? Either for the Volvo or OMC? Thanks guys.
 
This is just a suggestion.

If you were to use all Volvo Penta parts for this conversion, when the day comes to sell… you can truly make the claim that this is an all Volvo Penta sterndrive system!
 
I can't argue with that, but I have the issue that some of the Volvo parts are burnt. I would like to know what parts are the same so that I don't have to buy Volvo parts to have complete Volvo and OMC assemblies.
 
Last edited:
Back
Top