X-18 conversion from Volvo Penta 270T options...

[Dan]

Dear All,

I have a 1973 X-18 with Volvo Penta 270T drive; this is the drive/transom assembly with the single hydraulic cylinder inside the boat connected to a yoke for trim and tilt - there is also a plunger located at the bottom of the assembly. While in the process of refurbishing this unit, I am also considering other options for trim/tilt.

A few questions for the experts:

1. Has anyone converted from 270T to any other Volvo platform (for example the 280 transom assembly with the trim cylinders on the outside?) Will the assembly be exact fit?

2. Has anyone used the Mercruiser conversion transom assembly (this item fills the hole from larger Volvo to smaller Merc and allows for conversion to alpha and bravo).

Thanks in advance for any guidance.

Dan

[mattyboy]

I am not sure about the exact cut out of the 270T the 270T was an island unto itself it had unique parts so I don't know if the cutout was the same for the non T models.


things to take in to consideration the 280PT with the trim rams on the outside did give you trim and only 2 holes needed to be drilled outside of the cutout for the trim lines. The only real issue is these trim fittings and ears on the transom plate are OUTSIDE the transom seal and can leak causing rot in the transom plate and the transom . Volvo realized this and the 280 PT was short lived and was changed to the 290 which is a bigger cutout they redesigned the steering and transom plate to include everything inside the transom seal .

The 280 PT also has a bit of a different steering yoke connection but whatever way you go the 270 T steering is one of a kind so you will have to make adjustments


here is the template for the 270 280 280 PT

http://www.lgdonziclassic.com/pdfs/280template.pdf


the cutout for the 290 is huge

I think I have a pic of it somewhere

the transom adapter plate I have no knowledge with, have seen pics that's about it one thing I know is the transom can only be so thick( from X to X) for the merc transom plate the volvo didn't really matter so you may have a thickness issue with the adapter plate


here ya go

[Dan]

Mattyboy,

Excellent insight. As always, thank you!

Has anyone out there converted to a Volvo 290?

Anyone have any 270T spare parts?

Thanks in advance,
Dan

[mattyboy]

there is a 270T drive on ebay now looks to be a 4 cyl drive with everything from the suspension fork down

[Pat McPherson]

I had a 75 18' with Volvo 280 and no trim. I had thoughts of using the transom adapter to mount a Merc with trim in place of the Volvo. The adapter plates I had found cost as much as filling the hole and re-cutting for the Merc.
I had quotes from $1000 to $1500 to fill the transom an recut for a Merc. In the end I sold the boat and bought a 87 20' Minx.
The 75 18' I owned is still around and the owner recently converted to a newer Volvo SX. Not sure what changes he had to make to the transom.
In my opinion, if you are going to take the time to swap the drive/transom use later model stuff so replacement parts are easier to come by.

[Dan]

Mattyboy: Thanks for the ebay link.

Pat: Agreed, much to consider.

[mattyboy]

the sx and omc and merc all have the same cutout and I agree if you are going to go for a new drive it should be a modern one.

transom work on an older classic can be a pandora's box

other things to take in to account is the motor, the 280t was designed to be used with power steering not sure on the 270T if you don't have a PS pump you may need to add one if you change from the 270T

with the old Volvo I find trim rarely used shallow water putting on the trailer they really are strong drives but not the fastest the newer sx and bravo are a bit faster.

[smidgen too]

Dear All,

I have a 1973 X-18 with Volvo Penta 270T drive; this is the drive/transom assembly with the single hydraulic cylinder inside the boat connected to a yoke for trim and tilt - there is also a plunger located at the bottom of the assembly. While in the process of refurbishing this unit, I am also considering other options for trim/tilt.

A few questions for the experts:

1. Has anyone converted from 270T to any other Volvo platform (for example the 280 transom assembly with the trim cylinders on the outside?) Will the assembly be exact fit?

2. Has anyone used the Mercruiser conversion transom assembly (this item fills the hole from larger Volvo to smaller Merc and allows for conversion to alpha and bravo).

Thanks in advance for any guidance.

Dan

I have a 1973 X-18 that had the 270T power trim, it was a nightmare. Also 270T has it's unique larger cut out compared to the 270 & 280 non power trim Volvo drives. I converted it to my own power trim using Merc OB trim cylinders & Merc trim pump. It's easy to make and it works. I have talked about here before as I have had this trim set up on many boats since 1975. You can read more about it by doing a search of my past post & Looking at post #9 here. http://www.donzi.net/forums/showthread.php?70355-1972-18-Volvo-270-to-Alpha-Gen-2-Conversion&highlight=trim

[f_inscreenname]

Like Matt says the 290 is a huge cut out. It’s the only transom shield I know of that will cover an OMC stringer drive hole with no fiberglass work.
It’s a shame they didn’t stick with the 280T design. If you are pushing a Penta there is no better transom shield. Almost indestructible, super simple design, can use any merc, Volvo, off brand trim pump you want. You can rebuild the thing out of a Home Depot plumbing department for Pete’s sake.
I often thought about the fact that the main seal didn’t go around the outboard trim lines. All I do to fix that is to use big soft rubber washers with RTV black gasket maker on both sides around them. For that matter I put a bead inside the main seal’s groove before putting it in the groove and then a bead on the outside of the seal before bolting it to the transom. If there ever is a flex in the transom from anything the RTV has it all locked in. I’ve had to remove one after doing this and it’s harder but not impossible to get off. Just to finish everything off, the holes in the transom that the outside trim lines come through are a little bigger then the pipes due to fittings and such so I fill the transom in with some 4 or 8lb 2 part closed cell foam so water won’t get in from the inside or outside and a screwdriver can chip it out if needed to be removed.
Another thing to consider is if you are not running exhaust through your outdrive then you do not want a 280. Drive’s case is bigger for the exhaust port. I use a 270 with mine (the run of the mill 270, like said the 270T has a different fork on it for the trim shield). The 280 will work without power steering but you may need to change the steering arm to the helmet.
IMHO if you want something you can do yourself without any fiberglass work the 280T is the thing to do and if it was me I would change the fork on the drive the OP has now but he could use any Penta from a 250 to a 280 even a 290 but again he would have to change the fork on the 290 (290 is just a 280 with a different fork).

[Dan]

Thank you ALL for the guidance.

Smidgen too, I too have a 73 X-18 (Hull #76). Are you still making parts for this set up or have any "extras" lying around for sale? It's the most efficient I've seen requiring no new transom assembly, drive, glasswork, etc.

Thanks in advance.

Dan

[smidgen too]

Thank you ALL for the guidance.

Smidgen too, I too have a 73 X-18 (Hull #76). Are you still making parts for this set up or have any "extras" lying around for sale? It's the most efficient I've seen requiring no new transom assembly, drive, glasswork, etc.

Thanks in advance.

Dan

I don't have any extras but they are not hard to make with all the parts & material found on ebay. I will put a diagram together & post it showing how I made them.

[Dan]

smidgen too,
A diagram would be awesome! Thanks in advance.

Sincerely,
Dan

[Christian]

Why not consider outboard bracket? maybe a merc 200 or 250 with stainless marine bracket, boat should really move!

Happy Thanksgiving all!

C

[murfman]

Mattyboy,

Excellent insight. As always, thank you!

Has anyone out there converted to a Volvo 290?

Anyone have any 270T spare parts?

Thanks in advance,
Dan


I know this is an older post, but I converted to the 290/SP transom plates on my Magnum. Here is my reasoning,
First the transom plates with the trim rams pop up on Ebay pretty cheap, ( i have seen them sell for as little as 250$ complete)
Second the larger cutout will allow you to raise your X dimension ~2" without having to do any glass work.
Third I like the clean integrated look of the rams compared to the swapped on setups.

http://i184.photobucket.com/albums/x205/murfman_photo/Magnum/image_zps9216cbdf.jpg (http://s184.photobucket.com/user/murfman_photo/media/Magnum/image_zps9216cbdf.jpg.html)

http://i184.photobucket.com/albums/x205/murfman_photo/Magnum/image_zps53e774ba.jpg (http://s184.photobucket.com/user/murfman_photo/media/Magnum/image_zps53e774ba.jpg.html)

http://i184.photobucket.com/albums/x205/murfman_photo/Magnum/image_zps81602460.jpg (http://s184.photobucket.com/user/murfman_photo/media/Magnum/image_zps81602460.jpg.html)

[Danny]

I went from the 270 to the 280T. Matty and f_inscreen are right on in what they are saying about the 2 outboard hydraulic lines and sealing .
I made my own template off another boat very similar to the one in the link that Matt posted. The 280T hole is cut differently to accommodate the two inboard hydraulic fittings and there are 2 separate holes to accommodate the 2 outboard hydraulic fittings. The mistake I made was in regards to the holes I drilled for the outboard hydraulic lines( just outside the cutout). The holes I drilled in the transom for the outboard lines were large enough to let the fitting on the end of the hydraulic hose to pass thru and connect to the inside fitting on the transom plate but impossible to tighten with a wrench . Fortunately I had preassembled everything for the trim and transom plate on the boat and hadn't sealed anything in place. My fix at the time was to separate the transom plate (not yet sealed in place) from the transom only an inch or 2, gaining access to the fittings and tightening the hydraulic hoses with a wrench and then sliding the transom plate back in place.
Down side is if I every have to replace the interior outboard hoses I would have cut the hose off flush to the transom and use a thin walled deep socket to get to the hose end off ( fortunately I drilled my holes large enough)and then add in a brass extension fitting between the fitting on the plate and the new interior hose. (Didn't realized at the time that you could even get these brass extension for hydraulic fittings that you simply screw on the interior fitting on the transom plate and then screw the interior hydraulic hose into) You need to make sure these holes are large enough so that you can tighten these fitting into to the transom plate with a thin walled deep socket and that the brass extensions are long enough to allow you to tighten the hose to the extension using a wrench. I would also seal the wall (exposed wood) of the holes you drilled and the cutout with epoxy to avoid any transom rot that Matty spoke about and then extra sealant and or foam around the hole on the outside between the transom plate and hull as f-ingscreen suggested.
Hope this makes sense. I apparently learn things the hard. Do it once do it right.
Danny

[mattyboy]

I can see having room to move the X up on a twin Magnum setup but in a single classic things might get a bit tight with hatch clearance. This X 18 does it have a standard hatch hinges in the back or does it have the hinges on the side and the hatch opens from side to side. They had some problems with the exhaust elbows and clearance with the back deck they cut away some deck where the back hinges would go I think it was with merc trs boats but not sure the one I saw with side to side hatch was a merc trs boat

[f_inscreenname]

The last Donzi 18 I did I used a Volvo 280T and a 454. Had to have the risers custom cut down and used a short hood scoop so the f/a wouldn't hit the hood.

http://i21.photobucket.com/albums/b264/f_inscreenname/2_12.jpg

[mattyboy]

nice work ! :yes: