Logo

Volvo Penta AQ150B | Volvo Aquamatic 250B

PCP

New member
Hi

We own a 1961 aluminium boat (Guggisberg Aluma) with a Volvo Penta AQ150B / 250B Drive, apparently swapped in 1969 to replace a weaker 4-cylinder engine.

As expected, at least one of the exhaust elbows is badly rusted and probably beyond repair. These parts seem to be unavailable as spare, though.

Can someone give us some advice regarding possible solutions - are there any conversion kits still available, or do we have to consider an engine swap - expensive and quite complicated because of swiss anti-pollution laws...

Thanks in advance

Patrick
 
You may have a 200 drive, with a 250 shift cover on it.
If you will post a few photos of your engine/drive, I may be able to tell you more about what you actually have.

If the drive and transom shield are the 250, there will be an exhuast down tube avaible that will make this work.
I may even have one here.


BTW, the "B" designation indicates that the drive was originally fitted with the 1.61:1 V-8 lower unit.

.
 
Hi Ric, thanks for that quick answer. Ill take some pics as soon as possible, it won't be before next week, though.

In the meantime, here's a pic of the defective elbow:

DSCF9006.jpg

Regards

Patrick
 
Hello

I have not yet been able to take decent pictures of the drive - but I do have the serial number at hand:

apparently a Volvo Aquamatic 250B from 1969, serialnumber 2508014

Are the first 3 digits indicative of the drive, or this pure coincidence?

Thanks in advance

Patrick
 
Your entire drive number would look something like this:
PZNR2508014 (plus an Alpha Character designation as per over-all gear reduction)

PZNR2508014D = 2.15:1 4 cylinder ratio
PZNR2508014C = 1.89:1 In-Line 6 cylinder ratio
PZNR2508014B = 1.61:1 V-8 ratio

The "25" designates that this is a 250 drive.

The 250 lower unit gear set will be "beveled"... not Hypoid, and will be a tad bit noisy compared to the Hypoid gear sets used in all drives thereafter!
Not to fear.... the lower gear set is stout!

.
 
Well thanks a lot for all these informations!

I finally got around to taking some more pictures of the exhaust system. The port side has been dismantled, while the starboard side does not look too well neither.

Any suggestions regarding where to find replacement parts, anybody?

Thanks in advance

Patrick
 

Attachments

  • ExhaustStarboard02.jpg
    ExhaustStarboard02.jpg
    54 KB · Views: 149
  • ExhaustStarboard01.jpg
    ExhaustStarboard01.jpg
    92 KB · Views: 190
  • ExhaustPort01.jpg
    ExhaustPort01.jpg
    56.8 KB · Views: 138
  • ExhaustStarboard03.jpg
    ExhaustStarboard03.jpg
    74.7 KB · Views: 133
Here's the complete drive number. Apparently it's a V-8 ratio.
 

Attachments

  • DriveNumber.jpg
    DriveNumber.jpg
    35.6 KB · Views: 106
The "B" designates that this transmission would have originally been fitted to a 1.61:1 ratio.
But the transmission may have been changed.
This engine very likely requires the 1.89:1 over-all ratio!
If the 1.89:1 ratio was OEM, the "B" would have been a "C" originally.
In order to know for certain, remove the prop and ring anode.
In front of the ring anode will be a ratio number stamped into the bearing carrier.
This number will be good if the gear set has not been changed out to another ratio.


OMC used the Buick 90-degree V6 - 225 CID back in the Stringer Drive days.
Is this perhaps the Buick V-6?
I don't see this engine model shown for the Volvo Penta, although apparently it does exist.
Here's a guy selling an AQ 150 intake manifold on e-Bay.
You may want to contact him and ask if he has any exhaust parts.


Barr normally offers a universal center-rise manifold, but I don't see any listed for this engine.
I think that some modification is going to be needed in order to make any manifold work in your scenario.

Here is a log style manifold and short/low elbow.
You'd have to make darn sure that your exhaust flapper was in excellent condition if these were to be used.
The Y-pipe would need to be cut and shortened (perhaps angled), and then rubber hose couplers would connect them..... possibly with additional off-set elbows.

Again, not sure what to suggest to you.


.
 
Sorry to revive this old thread...

Urgently need a replacement thermostat for the AQ150B. Does anyone know the spare part number or even better where I can get one?

Thanks in advance.

Patrick
 
For best response from this forum, please start your own topic and not jump on a 5 year old one that technically has nothing to do with your query.

To do this, use the "+ POST NEW THREAD" blue button on the "Forum Home: Volvo Penta Gas Engine Forum" page
on the left hand side of the screen.
 
Last edited:
Back
Top