Re: Help identifying my VP engine
Hi Guys,
The thread in the link below may help, the original poster there includes some good pics of the drive. They have a 1993 V6 with the 290 style DP-A duoprop drive, they call it a 431B, which kind of fits in those years.
My basis for my thoughts on this come from my own investigation (and confusion) as I researched my boat, a 1991 duoprop with 5.7 4bbl GM based engine. I found that mine can be called the AQ271C or the 570/DP. Both of these show up in the manuals and even the prop guide from Volvo. I was able to get an owner's manual for mine, there were 2 choices and are identical, one from AQ271C designation and one from 570/DP designation. When I order parts I use the AQ271C as all those parts and drawings fit. Mine has 570 on the flame arrestor cover. In the thread below I have AQ570 typed in but it is really only 570/DP as the designator in the prop guide and such
Seems like the 431B is the 4.3l "marketing" I.D. from those years, the AQ designator might be AQ205A as that is a GM V6 with 4bbl. The AQ175A is a GM based V6 with 2bbl.
"Those years" is what I call the crossover period when Volvo went with the SX drives and phased out the older AQ drives, like 1990-1995. It seems from 1995 and after you could go by the year somewhat.
http://forums.iboats.com/showthread.php?t=303222&referrerid=93825a