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290 dp help

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welshswampy

Regular Contributor
I've bought a 290 dp and was told it was an early 90's, 1.78 ratioed
Only number I can see on the plate is 29010859B, the last character could be an 8 or a 3
Anybody know of any sites that can ID it?
Regards Nick
 
The 290xxxxxB would have been a 1.61:1 V-8 ratio in the single prop. The "B" designates this ratio.
The "B" works for either the BB or the SB.
The 290 drive, whether s/p or DP, will have the anchorage bracket and cylinders that attach to this bracket.
It will also have the Rev Latch unit on it.

Anything after the 290 or 290A, such as a SP-C or DP-C or DP-D, will not have this bracket, and the cylinders will attach directly to the suspension fork.
No Reverse Latch either.

The Duo Prop V-8 ratios are 1.95:1 for the SB and 1.78:1 for the BB. .... there's also a 2.30:1, but this is not for V-8's.
Since all transmissions are of the same gear reduction, it's quite common to see that a different lower unit has been attached, so I'd not go by the transmission tag alone.

The best thing to do would be to remove the props, pull the ring anode, and wire brush the AFT-most end of the bearing carrier.
This will expose the over-all ratio number.
However, this number is only good if no one has changed a gear set.
They sometimes forget to stamp out the old number and re-stamp the new ratio number.

I'd still pull the props and look at the numbers.
If you have the BB engine, then you'll want the 1.78:1 ratio.
If you have the SB engine, then you'll want the 1.95:1 ratio.


A couple good pictures would help determine which drive you bought.
People confuse these all the time.

.
 
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Cheers Rick, will remove anode and check in morning
Dont have any props, that was gonna be my next question!
Would anyone have an idea of what props i am likely to need
GM V8 diesel 170hp pushing a 24 ft bayliner trophy( I'm guessing around 3 tonne)
I know the max RPM and WOT formula, but I'm hoping someone could point me in the right direction before I go bankrupt buying and testing props!

Regards Nick
 
Thanks kimcrwbr1, but I cant access that site, it says that its only for US residents
Isn't there a site that I can just tap the serial number into?

Regards Nick
 
kimcrwbr1 said:
What I am seeing is DP-D1 has that gear ratio for your drive there should be a ID plate on the upper gearbox by the drive bellows. You can probably ID the engine by how the parts look they seem to have their own distinct arrangements from model to model. The seasoned mechanics here can tell you just from a pic.
Click to expand...
Well, that would work except that the "B" indicates an original V-8 ratio single prop drive.
Nick is now wanting to use this with a GM 6.2 diesel engine and a 1.78:1 Duo Prop lower.
This should be the correct ratio if the torque numbers are up there.

Nick, as for props, you're at the mercy of trial and error and your WOT RPM.
I'd probably start with A's or B's in a 2 or 3 and give them a try.

.
 
outdrive and engine 005.jpgoutdrive and engine 012.jpgoutdrive and engine 015.jpgoutdrive and engine 014.jpgoutdrive and engine 016.jpgoutdrive and engine 017.jpg



Just removed the anode ring and found the ratio numbers and some letters on the casing behind
Have added some pictures
Last picture shows 1.78-1 so I'm assuming thats OK, as long as no-one has changed the ratio
Fifth picture shows an H and K pn one side of anode fixing hole and an A on the other, not sure if its visible on this photo
Maybe some one can recognise the model from these pics

Regards Nick
 
Sorry, my mistake the letters read K and A on one side and an H on the other
The pics are the right way up, the numbers and letters are upsde down
 
Nick, that drive is a 290 and probably a first generation 290. Definitely not a 290A.
The suspension fork, the anchorage bracket, the reverse latch, the bearing cross style, the top cover, the separate BB clamping collar, are all dead-give-a-ways.
Not a bad drive at all, it's just not an A drive, and certainly not a C or later drive.

It should work just fine as long as it's good.
Build the puller tool, and remove the prop shaft bearing carrier.
Nothing re; shimming changes, and it will cost you two O-rings only.

.
 
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Cheers Rick, will have a look on this site for the tool specs and make one
I am trying to carry out a compression test, but having trouble with the thread of the drain plug, being 3/8 UNC (i think), I cant seem to find a test nipple or adapter to get me to BSP or metric of the shelf over here, I'll make a few more local enquires then get one machined up if I blank
 
Nick, I may not be following you. Are you talking about doing a pressure/vacuum leak-down test on the drive?
The threads in the Duo Prop will be US or American N/C threads, inlcuding the drain plug threads. No Metric!

.
 
Yes Rick,(oops, misled you calling it a compression test) I would like to do a pressure/vacuum test, but the female thread for the drain plug appears to be 3/8 UNC
My test equipment is BSP and metric, and I'm having trouble finding an adapter, so maybe I'll pass on it
Was gonna do this instead of stripping it apart, was told it had new seals, water neck fitting, filled with oil then left to stand for a number of yrs
Goes into gears easily, turns as it should and everything feels nice and tight, so, apart from checking the bearing carrier as suggested, I'll probably try it as it is
Just hope I wont regret it!
 
welshswampy said:
Yes Rick,(oops, misled you calling it a compression test) I would like to do a pressure/vacuum test, but the female thread for the drain plug appears to be 3/8 UNC
My test equipment is BSP and metric, and I'm having trouble finding an adapter, so maybe I'll pass on it
Was gonna do this instead of stripping it apart, was told it had new seals, water neck fitting, filled with oil then left to stand for a number of yrs
Goes into gears easily, turns as it should and everything feels nice and tight, so, apart from checking the bearing carrier as suggested, I'll probably try it as it is
Just hope I wont regret it!
Click to expand...
Nick, if for no other reason, at leat pull the prop shaft bearing carrier and examine the gears and the several bearing surfaces that will become exposed.
As I've said, the cost to do this is what it takes to build the puller tool and two stinking O-rings ONLY!

In the transmission, the most suspect area will be the eccentric piston seal.
You can replace this seal and one O-ring without pulling the entire drive apart.

FYI: most of us who know these drives, will be removing and re-installing them with the transmission OFF.
Install the transmission last!
Cost to do this is two OEM O-rings ONLY.

This is from my 23 years experience of working on the Volvo Penta AQ series drives.
Do this now, and you'll never know what headaches this may have prevented.

.
 
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I'll make the checks you mention my next job, it wont be straight away(very busy with other stuff at mo)
I realise that your trying to help me and not advising me to do unneccessary work, so thanks
You'll all probably be sick of my questions over the next few weeks, but if you can, keep answering!
Cos everyones answers are appreciated

Regards Nick
 
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