Volvo to mercruiser conversion

[floorboy]

Ok, I am converting over from a Volvo 280 drive to a mercruiser alpha. I have replaced the transom and had to tear out the motor beds in the process as the were wet. Took a pile of measurements and pictures as well as saved the old beds for reference.

Question I have is, and I can't find it anywhere, will the location of the old beds be close to where the new ones will be? Within the adjustment of the mounts? I can't find any info on it. I know there is an adapter plate to do the job so I imagine the motor would be in approximately the same spot. Thanks.

 

[Bondo]

Re: Volvo to mercruiser conversion

Ayuh,.... To find the measurement 'n placement of the motor mountin' blocks,....

Mount the transom assembly, hang the motor on the rear mounts, on yer hook,...
Adjust the motor's alignment with yer bar,...
Wherever the motor is hung "In Alignment" is where ya build up the mounts too,...

Then pull the motor back out, build the mountin' blocks, 'n drop in yer motor,....

'n, No, there ain't no short-cuts,...

 

[floorboy]

Re: Volvo to mercruiser conversion

Ok thanks.... Unfortunate.

 

[Walt T]

Re: Volvo to mercruiser conversion

If you want a Mercruiser powered boat, buy one. Now it doesn't matter, whatever you use you'll have to painstakingly align and mount it all

 

[HT32BSX115]

Re: Volvo to mercruiser conversion

Question I have is, and I can't find it anywhere, will the location of the old beds be close to where the new ones will be? Within the adjustment of the mounts? I can't find any info on it. I know there is an adapter plate to do the job so I imagine the motor would be in approximately the same spot. Thanks.

They might be close but the process will still be the same.

1. Measure the "hole" (transom cutout),

2. Mount the gimbal mount,

3. Mount (and support) the engine to the gimbal mount,

4. Align the engine,

5. Locate and install (glass-in and drill etc ) the engine mounts

6. RE-check and re-align the engine.

This is EXACTLY what I had to do replacing my former 460 OMG King Kobra with a MUCH newer Mercruiser 454/Bravo combination.

The transom cutout was pretty much exactly the same for both drives but the engine mounts weren't

 

[floorboy]

Re: Volvo to mercruiser conversion

If you want a Mercruiser powered boat, buy one. Now it doesn't matter, whatever you use you'll have to painstakingly align and mount it all

I would but I'd never find another one like the one I have. 34 years old and in showroom/ unrestored/ freshwater condition. I traveled from sw Mn to Massachusetts and looked at quite a few of them for sale. Most were beat and you don't find any of them around here. (Seacraft) I'll have it until I die, I don't mind the work and I have the facilities to do it. Thanks

 

[HT32BSX115]

Re: Volvo to mercruiser conversion

I would but I'd never find another one like the one I have. 34 years old and in showroom/ unrestored/ freshwater condition. I traveled from sw Mn to Massachusetts and looked at quite a few of them for sale. Most were beat and you don't find any of them around here. (Seacraft) I'll have it until I die, I don't mind the work and I have the facilities to do it. Thanks

That boat restored, would be worth spending some time and money on a re-power.

 

[Lou C]

Re: Volvo to mercruiser conversion

Are you sure that you need to convert? Many feel the older style Volvo drive design is superior and the main issue is finding some of the parts and techs who can work on them. Just like I've done with my Cobra, you could figure out what might go bad on it and try to source those parts as spares and just keep it going. I am going to look for a spare 4.3 OMC drive for the old Cobra. I'll have my OMC shop go through it and then store it in the garage. I already have other spares like trim rams etc. I like the OMC better than the Merc Alpha. I don't see an SEI Drive particularly as anywhere near as good quality as the originals and that is what many people are converting to. Mean while my original is 25 years old and works fine.
To me there are less unknowns that way, than rebuilding the whole transom/engine mounts, unless you can find a 'glass shop that has done that already, and/or the transom/mounts are bad and need to be done anyway. You are going from cone clutch shifting to a dog clutch, you might not like the rougher shifting of the dog clutch. Ever driven an Alpha powered boat? Comparing both a properly set up Cobra shifts better and a Volvo is in a different league. But if all you want is the easy availability of the Alpha, then that is what you gotta do. Me I'd research sticking with what I have....

The Volvo 270/280/290 series has a much larger cut out in the transom than the later Volvo SX design, so converting one of them is not anywhere as easy as converting an SX to a Merc for example. That bigger hole in the transom has to get filled in and re-cut, or the adaptor plate (If you can even still find them) can be used to take up the slack. The job of re-doing the transom from the 280 hole to the Alpha/SX/Cobra hole is one that requires a lot of precise measurements.

not sure how well this works, but its an option.....

http://bpi.ebasicpower.com/mm5/merc...oduct_Code=MER827691A1&Store_Code=eBasicPower

 

[floorboy]

Re: Volvo to mercruiser conversion

It is too late for the Volvo anymore. I sold all the stuff I took off. Bought a donor boat with a new motor (verified by the serial number) and a fresh rebuilt drive.
The transom itself was down to bare glass a month ago or so and has been rebuilt from the ground up. I have the drilling jig and all the necessary tools to do the job. Another couple coats to finish off the outside of the transom and I can cut the hole. I have a complete spare setup, motor-drive, and the gimbal housing will be rebuilt before I put it on. I don't know why I would ever stay with something that is wore out and chase down fixes all the time. Our season is too short around here to be down for very long. Not to mention where is fish is 9 hours from my home so it is a trip killer if I break and can't find parts. Last year I spun a hub on a prop and I was done fishing. That brings up another sore subject, the props on the old volvos are not interchangeable with anything and the towboat style prop is performance wise to boats what the cavalier was to performance of a typical Chevy. Steering feedback of that old thing cost me $700 in a hydraulic steering system because a physically couldn't hold onto it for a half an hour, and I don't work behind a desk. I broke a steering helmet bolt going out of the harbor in the dark and almost ramped the wall at 3 a.m.... Am I going to miss that Volvo??? Probably not. Is an alpha the best choice??? Probably not. Has it proven itself? I think so. Are parts available for it just about everywhere? Ubetcha.

 

[Bifflefan]

Re: Volvo to mercruiser conversion

Just to add a log to the fire,

Why not plug the transom hole and go with an OB on a platform, or maybe two OB's.

Could be fun.

 

[floorboy]

Re: Volvo to mercruiser conversion

Thought of it, thought hard. A lot if guys do it on these. (Seacraft sceptre) one guy that a buddy of mine bought and identical boat from in Mass told me not to do it. He said if I am buying this particular boat for the ride that changing the center of gravity with a bracket would defeat the purpose. I would have loved the extra deck space, but then you have to fish around a motor. (We troll on the Great Lakes). I gave it some serious thought and it lost. I am comfortable rebuilding a "gm" 350, I am lost when working on newer outboards.

 

[cr2k]

Re: Volvo to mercruiser conversion

How bad can it handle at trolling speeds?

 

[floorboy]

Re: Volvo to mercruiser conversion

??? How bad can what handle???

 

[JASinIL2006]

Re: Volvo to mercruiser conversion

My Larson was repowered before I bought it, from a 4.3 VP setup (I believe) to a Merc 350 Mag Alpha One Gen 2. The motor mounts were almost identical in height... just bumped up a bit -- about a 1/2 shim was added between the old mounts and the new. The new forward mount locations are several inches fore of the old locations.

 

[floorboy]

Re: Volvo to mercruiser conversion

Thanks JAS.