Logo
FULL SITE MENU

Volvo AQ170 max RPM and volvo V6 4.3GL couple to a 280 outdrive "C" ratio 1:89

C

Capt Tom

New member
Have a AQ 170 on a 1972 20' sea craft. What's the max rpm for the AQ170 WOT? Need to know if my prop is the correct one for the AQ170. Also would like to consider an engine change to a 4.3GL 190hp for better reliability.
 
You will need a year model correct OEM service manual for your WOT RPM for either of those engines.

The 4.3L 190 hp may allow for using the B ratio (1.61:1) on a smaller 20 footer....., although a more difficult and expensive ratio to find.
I have a Flywheel Cover, Y-pipe and Transom Shield for this conversion if interested.

The 1.89:1 is also known to work. These are a dime/dozen.

Do note that re-shimming is required when changing to a different lower or transmission on this drive.
 
Tom,

What boat is it in. What revs are you currently pulling? I Have an AQ170 reco'd im looking to offload. Im in Aus if you know anybody interested by chance.
 
Volvo let their 2.0 liter 4-bangers on which the AQ170 [3.0 straight six] rev to at least 4800 and the owner's manual says on light, fast boats they'll let 'er rip to 5200, with continuous power to 4800 on that application. I would bet this is a bit higher than GM would care to go on their V6..remember, you don't have Mahle pistons in that motor and I doubt the rods and crank are forged, either. So, the safe bet on the GM block is probably 4200/4400 so I'd step up in pitch. You're adding around 80 cubic inches in displacement so you will need more bite anyway. If you want to swap drives I'll take the C lower off your hands for a B [1.61 unit].
 
Tom, if considding the 4.3L, I'd take him up on that 1.89:1 trade for the 1.61:1 .
There is no propeller substitute for the correct over-all ratio for the engine.
 
owners manual for the AQ170A says 5000 rpm max and says to prop the unit for a WOT rpm of 4200 to 5000
 
Back
Top