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Can an SP 280 drive match and AQ271 motor set up?

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BishopG

New member
I am new here and hoping to get some help. I have been working on a conversion for my boat and have installed a completely rebuilt AQ271 (only I downsized it to a 305 motor) and Volvo Penta transom assembly for what appears to be an SP 290 out drive. She is all hooked up and ready for the out drive. I have available to me a SP 280 drive with 1.61 ratio. Can I make this match up somehow?
 
BishopG said:
I am new here and hoping to get some help. I have been working on a conversion for my boat and have installed a completely rebuilt AQ271 (only I downsized it to a 305 motor) and Volvo Penta transom assembly for what appears to be an SP 290 out drive. She is all hooked up and ready for the out drive. I have available to me a SP 280 drive with 1.61 ratio. Can I make this match up somehow?
Click to expand...

The SP (in upper case characters) drive followed the 290 drive.
There is no SP 280 nor SP 290 that I am aware of.
The s/p (in lower case characters) means "single prop".

All AQ series lower unit can be made to interchange.
Not all AQ series transmissions can be made to interchange.


If you are wanting to install a 1.61:1 280 lower unit onto an SP or 290 Intermediate housing, you must take the A and B measurements and follow the shimming procedure.

See the OEM service manual for the procedure.



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Thanks for the quick reply... also, forgive my ignorance here but, the nameplate on the drive says 280B 1.61 On the decal, which is on the outside of the housing it has in upper case letters "SP".

My concern here as I manually look at it is that the outer transom spacing for the control arm is 11" inside to inside, but the outside to outside dimensions on the control arm of the out drive is only 10 1/2" leaving a 1/4" gap on either side. Is that acceptable? and can it be shimmed with washers or something like that?
 
2015-09-19 14.31.15.jpg2015-09-19 14.31.28.jpgTransom.jpg
 
The drive designation will be on what was typically and formerly called the "PZNR" tag.
The PZNR tag is right where Kim suggested it would be.

Most all 280's began with PZNR 28XXXXXX ...... then followed by either B, C or D.

B = 1.61:1 ratio (all V-8 gas engines [big or small block, Ford, GM or Chrysler] and some Diesel engines)
C = 1.89:1 ratio (in-line 6 cylinder, some V-6 gas engines and some Diesel engines )
D = 2.15:1 ratio (all 4 cylinder gas engines)

Later the "PZNR" was dropped from the tags.

In all of my years working on the AQ series, I don't recall seeing the 280B 1.61:1 designation laid out like this on a PZNR tag.


The bump on the side of transmission's bearing box says "A" transmission (i.e., integral aluminum bearing box/clamping collar)

The suspension fork is from a 280/285/275 with mechanical lift-out unit (no power trim).

The lower unit could be a 280/285/290 in any of the ratios (ratio will be stamped into the prop shaft bearing carrier).

The transom shield is a 290 or a later C drive (need to see close up photo)
(small solid hinge pin = 290 family)
(large hollow hinge pin = C and later family)

In either event, the suspension fork shown will not mate with this transom shield.
 

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Thanks so much for your help, Rick (and others) although, it sounds like you are giving me bad news. I was hoping to use the drive I have but, it sounds like you are saying it won't work :(

Just so I am clear... I did look at the nameplate at the top and it says exactly what I said before. There are no "PZNR" codes on the plate. It simply says "280 B" then a space and "1,61". There is also a serial number below that and a 6 digit number in the right hand corner of the plate which appears to be simply the part number for the name plate. I am having a real hard time finding a drive unit to fit without having to sell my first born child ;) Do you have any suggestions??
 
Let us know if the suspension fork hinge pins are small and solid, or larger and hollow.
If small and solid, you will need to fit a 290 style suspension fork and anchorage bracket onto your Intermediate housing.
If larger and hollow, you will need to fit a "C" or later suspension fork onto your Intermediate housing.


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If you are referring to the hinge pins that attach the suspension forks to the transom housing, they are small and solid - approx 5/8" diameter. Any thoughts on where to find a 290 suspension fork and anchor bracket? Thanks again.
 
BishopG said:
If you are referring to the hinge pins that attach the suspension forks to the transom housing, they are small and solid - approx 5/8" diameter. Any thoughts on where to find a 290 suspension fork and anchor bracket? Thanks again.
Click to expand...

OK... it took some teeth pulling :D, but we now know that you have the 290 style transom shield.

I can sell you a brand new anchorage bracket and the fasteners for next to nothing........., but I do not have a 290 suspension fork.

Try e-Bay.

Caution: often these are mis-categorized and mis-labeled, so watch out for sellers who DO NOT know what they are selling.
There is NO large pin 290

You want a small pin suspension fork for a 290 and with the attaching points for the anchorage bracket.
 

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Been lurking on this thread and can't help asking... Why are you going from a 5.7 to a 5.0L engine?
How big and what kind of boat do you have??? When I went from a 4.7L V8 to a 5.7L on my deep V boat, my fuel consumption improved markedly ( 10 gph to 7 @ cruise) and my top speed increased and my cruising RPMs dropped markedly.
 
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Okay... sorry about that... I knew I had the 290 transom shield - guess I didn't make that clear. What I was trying to figure out was whether the 280 drive could be made to mate up with the 290 transom shield. Now I see what the problems are based on what you have tolsd me. I did find a complete 290 drive just like the one you show in the bottom of the two pictures you just sent me. It has the hydraulic lift bracket that you show there. The only problem is that the name plate on it says it is a 290 A with a gear ratio of 2,15:1 which I understand is for the four cylinder engine. Would I be able to make that work somehow?

RicardoMarine said:
OK... it took some teeth pulling :D, but we now know that you have the 290 style transom shield.

I can sell you a brand new anchorage bracket and the fasteners for next to nothing........., but I do not have a 290 suspension fork.

Try e-Bay.

Caution: often these are mis-categorized and mis-labeled, so watch out for sellers who DO NOT know what they are selling.
There is NO large pin 290

You want a small pin suspension fork for a 290 and with the attaching points for the anchorage bracket.
Click to expand...
 
It's a bit of a long story, Bob. Here is the short version... I have a 1979, 27' Century 7000 cruiser that I have mostly restored (see pic). It had been fitted by someone with a 454 big block with a merc tranny and a TRS out drive. Way too big and heavy for the boat. I took all that off and sold it and took all the Volvo parts from a scrapper boat that I have which had a 350 Volvo (damaged) with the transom components and no out drive. I found a 305 block and had it completely rebuilt (long block) by a local custom engine builder and a local mechanic sold me the 280 drive and told me it would work. He has since disappeared with my money and I am stuck... I should have known better but, he assured me the 280 and 290 were interchangeable. I also wanted a smaller engine because I always cruise at about 8 - 10 knots and am not looking to go too fast - hoping to save a little fuel... (??)7000 side view on trailer.jpg
 
It takes torque to turn a prop and CID to make torque. that is how come I got better results with a 350 vs the origial 283. That said... my hull has a 22 degree dead rise and like its Bertram cousins, "gas hogs". Your dead rise should be more moderate and hence you'll need less to push it. If I were starting this project and wanted to dump the 454 in favor of a smaller engine and better fuel burn at a reduced speed, I'd probably go with a 5.7 and not a 5.0.
If all you want is 8 to 10 kts @ cruise RPMs, you should be OK with the 5.0.
 
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BishopG said:
I knew I had the 290 transom shield - guess I didn't make that clear. What I was trying to figure out was whether the 280 drive could be made to mate up with the 290 transom shield. Now I see what the problems are based on what you have tolsd me.
Just change out the 280 style suspension fork to a 290 style suspension fork.
The transmision and lower unit will need to be removed from the Intermediate housing, and all O-rings will need to be replaced.... but it can be done. If nothing else is changed, there will be no change to any shim values.

I did find a complete 290 drive just like the one you show in the bottom of the two pictures you just sent me. It has the hydraulic lift bracket that you show there. The only problem is that the name plate on it says it is a 290 A with a gear ratio of 2,15:1 which I understand is for the four cylinder engine. Would I be able to make that work somehow?

You could make all but the lower unit work.
The 2.15:1 ratio is incorrect for your engine!

Easiest solution will be changing out the suspension fork.
Click to expand...
 
While the upper transmission tag says 290A, the front collar tells me differently.

If you purchase this, you'll be paying for a drive with an incorrect ratio lower unit.

I think that it would be cost effective to simply swap out suspension forks.
 
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