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View Full Version : Volvo 250 to a 290 (internal trim)



oldLenny
09-08-2002, 01:00 AM
I've been wondering lately, about the thing hanging off the transom on Scot Van A's OLD boat and was wondering if it might be better to keep something "white" hanging off the back instead of a Merc.

Talking with a mechanic (boat) buddy today, (who absolutely swears by Volvo and not Merc) he suggested getting a 290 and bolt it in place of the 250. He was unaware of the exact bolt location differences, but said if so they would be minor, and the cutout should be the same only make it a bit bigger.

Now I know that there are going to be many people here that KNOW the RIGHT answer to this question. Hence, I'll ask it here. If I opt for a 290 with internal hydralic trim, will it fit without destroying the transom, or am I going to have to do the fill and fair thing anyway?. And, if it does fit, where does it place the cavitation plate (x-dimension) in relationship to the original 250?

Thanx in advance. (I prefer the black ones but in a resto-job the white might look better but I don't want the electric motor driven trim in this case, My buddy told me that the 290 is the first truly hydralic unit. I am totally ignorant in regards to motor/drive issues)

BigGrizzly
09-08-2002, 02:00 AM
I ts exact job to my Corsican. It was a easy. First i made a template of the 250/270 base then one of the 290 and overlaide the templates. woring from the center(drave shaft hole) I was able to make a carboard template. Then I drilled te holes for the 290. The 290 has studs not bolts. I then started fitting the transom plate. I ended up cutting off 1/2-3/4 inch in two area on the port and starbord sices anw a small notch on the top of the cutout. I was cut to fit only so as not to change much. I resealed sealed the wood with polyester installed the drive and pump and went to the lake. The job took a weekend after the template was made. I didn't even have to move rhe engine.I did it with the engine still in the boat. The true X dinention is the same no deeper. I did however put on a hydromotive nose cone. This does improve the handling not the speed. Answer to the next question is, Yes I would do it again. This was the most single improvement that can be made on the older Donzi. Answer 2) yes it did go faster and ride better. The best part was nothing else had to be changed and I have the Volvo durability and smoothe shifting.

Randy owner of Donzis since 1966

ToonaFish
09-08-2002, 02:31 AM
That would make a good post in the technical section, Randy. (If I can understand it, anyone can!)

What are you planning for power, Lenny?

Formula Jr
09-08-2002, 05:02 AM
Len, I've been a life long fan of merc stuff, but now that I've really looked at why I was a fan, it was based on the outboards. I understand the Alphas, and if you look at them closely, its a very poor design with alot of "after thought" engineering in it. The ignition interruption switch system used to release the clutch dog is a brain dead design. To get any speed out of what your boat will eventually be, you'll need to run the same type of 1.3, or there abouts ratio, and you know how fast my boat moves at idle. That has always meant alot of in-out gear play in close quarters. I'm alittle tired of the stalls when she is hot and I need some precision gear shifting action to dock. The tides and currents on The Sound drove this home. In your area, the drive just has to work right all the time. There's little margin for error at a dock filled with American mega-boats. :D

BigGrizzly
09-08-2002, 08:26 AM
JR, Volvo doesn't have a 1.3 gear, The beauty of the swap is he can use the foot from the 250/270 and bolt it to the 290 top. infact he can swap all the pieces and use most of the transom plate wih the trim only. I did this 5 years ago and didn't have a dig camera so only my memory and the boat ate left no pictures. I do know a guy who has done the swap at least 6 times, on different boats. Lenny just do it. The merc will take forever or put on the Volvo adapter plate and bolt the merc to it, and wait for it to break. Unless you put on a new style Bravo your wasting your time

Randy owner of Donzis since 1966

oldLenny
09-08-2002, 09:52 AM
Got it!..thanx Griz. I am going to look into this a lot more now. Volvo legs are in abundance here and half the price of MERC's. I might add, (and I know nothing about)"this" mechanic told me that the "SX" drive that they came out with uses all the same top end as the 290 and was created to suffice the demand for "something that looked newer" by anxious boat owners.

(Randy, no, I wasn't ever planning on putting on a Bravo on the 16) It WOULD have been an Alpha GenII. I was not going to "fit" it with the transom assembly that is currently on there, I was going to do a fill and glass thing and re-cutout with a NEW unit.)

I agree with the above. What a great article for a "technical peice". :D Thanx

Can you get a 290 that spins left?

Wildfire
09-08-2002, 10:22 AM
I'm not 100% on this, but I think all you have to do to change the rotation of on the Volvos is to remove the cover plate on the back of the drive and switch the shift rod from the side it is on to the other side.

Try taking the cover off and observing the operation of the shift mechanism, it will probably be obvious what needs to be done.

Basically, you run in what used to be reverse. Sounds confusing, but the service manual shows how to do it.

RH
09-08-2002, 01:00 PM
Lenny and company, I am reading these post with great attention. I have the 270 drive on the 72' Hornet without trim. I am running the 350 SBC and have been thinking about the 290 drive swap myself. Reason being is for trim reasons. I am thinking that having the trim would really free up the hull on my Hornet and allow for some major increases in speed. Would anybody care to interject their thoughts on this.
RH

Formula Jr
09-08-2002, 03:31 PM
The 250A had a 1.35 : 1 ratio............. :D

Ratios go as follows:

250A - 1.35
250B - 1.61
250C- 1.89
250D- 2.15

270s and 280s came with any of the last three ratios.

Standard DP G- 1.95
" " H- 2.30

Changing from RH to LH on a Volvo is as easy as moving the shift rod from one side of the shift yoke and eccentric arm to the other side. Everything is already setup for the change.

I'm not going to bother with drive trim on the GT. I'm just going to set the drive for best WOT trim and then use the Bennetts for any bow down conditions. Funny that Mercs are more spendy than Volvos in the Great White North. Merc is a Canadian Company.

Blewbyu
09-08-2002, 06:18 PM
Lenny-As you probably noticed, I have a 270 upper case, and 290 lower bolted to the bottom.Of course this doesn't address the trim issue, but just want you to know that this combo has taken 12 years of HARD use, with regular oil changes.It has been BULLETPROOF!!!I run 3 holes out, and the boat airs out very nicely with a Spinelli 14 3/4X 22 round tip (lotsa rake).No need for trim.The electric motor 'tilt' really sucks tho-blows a 20A fuse about every 3-4 times tilt is used.Cutoff doesn't work.Fuses are cheaper that rebuilt tilt motor.Though Volvos are slower, it's because of the beefy gears and bearings in the lower section make for a bigger case.But-that's what gives you the dependability.In your neck of the woods-dependability means a hell of a lot more than an xtra 3 MPH.Believe the 250 upper is the same as the 270 (strength wise)as far as gears and bearings go.If a Volvo should ever crap out (seldom), you simply lift it off and use it for an anchor,and buy another used one on the net.The cost of their hard parts is pretty frightening! :D

Formula Jr
09-08-2002, 07:42 PM
Jeff, since you've done all the hard work finding the perfect prop for your 18, what drive ratio is in your 270 upper? I'm thinking that since Len's boat is a bit lighter, and that his engine will be a milder version than yours, that the same combo should work very well. But I have this feeling he will not be happy till he sees the Canadian Ton. (100 Klicks an Hour.) wink

oldLenny
09-08-2002, 08:33 PM
Owen, I won't even crack a smile until I am faster than Jamie Root. This involves at least 68.7 gps MPH. I have a LOT of work ahead of me. :D

...Jeff or anyone else need one of these?
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=1857356685

BigGrizzly
09-08-2002, 10:21 PM
Actually the term slower than Merc is incorrect. The fact is the alpha is on an even keel with the Volvo with trim. the bravo is actually slower on the same boat. Jamie's boat is fat because of the engine, not the drive. People who have seen my Corsican run will tell you Fords and Volvos arn't slow. Jr Thoes other ratios were uses on hous boats and small displacement 4 cylinders and were re3ar in te us market place. The 1.61 was known as the V8 set and 1.89 the 4 cylinder set. My 1966 16 has 1.61 set in it.

Randy, owner of Donzi since 1966

Moody Blu'
09-08-2002, 11:45 PM
I'm glad to be reading this.

I use to like mercruiser but after reading all the problems herer and over at oso. I am stuck on volvos. (just like when I got my boat and it had a ford in it)- I was a chevy man before that so i didnt like ford-because dale earnhardt R.I.P. was a chevy boy, but then again, all those nascar motors are the same..what did I know?

I am doing a swap this fall/winter/spring?-whenever I get around to it.

I belive I have a rare 270/275? drive with tilt and trim.

I will try to take as many pictures as i can and try to write up a how to. I belive my first how to was ok, but my wording needs some work.

hmmmm anyone need a how to on how to stroke a 351w to a 420w CI? wink