Had some visitors over, and the discussion went to Volvos and then boats. He mentioned that Volvo made (did make) a great inboard motor. I stated that to my knowledge the motor in my 760 was the same motor.

The discussion then went on (his comments) about how the marine version would have to have a special valve train and would be beefed up in other areas to withstand the continuous high rpms.

True or false? Is this motor still being used in boats? Is there a way to get a brand new B230 motor/short block? Is the marine version that different?

Don't really plan on doing this any time soon - just thought it would make interesting talk.
--
"Be blessed in your quest'' 89 764 (110K), '94 940T (180K) , '92 745T (totaled 2-10-05 RIP)

Volvofolk, The marine 251A shortblock retails for $4073.20 and costs a Volvo Penta Marine dealer $2443.92 plus shipping. It is brand new OEM and who knows how many there are and for how long they will be available.

We can dream, can't we?

I have read a thread about someone and a brand new motor and his impressions, but I do not recall where. I wonder if that individual spent that much?
--
"Be blessed in your quest'' 89 764 (110K), '94 940T (180K) , '92 745T (totaled 2-10-05 RIP)

http://www.lidingomarin.se/pdf/Volvo/SECTION%2003.PDF

This is a parts spec list for the marine series, but not a block comparison

Also note that the AQ171 was known as the 251A as well, bu the 251 is a carb version

http://forums.turbobricks.com/viewtopic.php?t=9434&highlight=:wave:...

From Turbo Bricks:


B230 block bored to 97mm and stroked with a marine crank to 103mm, 3045cc. Stefan Verdi rods and Venolia pistons. Timo ported 531 head, with 50/40 valves, 306 degree cam (ground by Timo?). Double Weber 48's. Sten Parner 4-into-1 header, w/48mm inner diameter to 3' collector, 3" exhaust. 324hk @ 8300rpm, M50 trans, 4,10 axle w/LSD.

Volvo made a Penta series of the B21/23/230 motors for boats. They apparently had cylinder heads with improved flow in the case of the eight valve motors and in the case of both the eight and sixteen valve motors, higher lift and longer duration camshafts. The sixteen valve marine motor was based on the B230 automotive eight valve engine, not the B234 automotive sixteen valve engine. Further, the crank in the sixteen valve engine was a "stroker," meaning it had 86 mm stroke rather than 80 mm, for 2.5L displacement. The B230 marine motors also had forged crankshafts.

I have one of the Penta AQ171 sixteen valve, 2.5L B230 based motors that I will be rebuilding, turbocharging, and putting in my 740 or 940.

Philip Bradley

check the turbobricks forum. I recall a thread about using the aq171 crank in a red block....

But I would like to know if the aq171 can be used in a 740 w a turbo.

BTW, the penta also comes in v8.....

The AQ171 could be used, but you need a manifold for the 16V. I have a header for the turbo. Some AQ171 have skinny connecting rods, like the early B230, and should be upgraded before turbocharging. The B230 block is just like any other B230 block. You also need a tensioner for the timing belt. There is a Penta part, but people have also adapted parts from other cars. I bought mine from Dick Prince, who has been running a B230 16V Turbo in a 740 for several years. www.ovlov.net

Philip Bradley

That is interesting, as I just read about fitting a 16v head to a B230.

That is neat. How much modification has to be done - like in the mounts - water pumps and all on the front. Is a lot of it just bolt on stuff to make it fit in a car?

With the increased stroke, do you have an idea what kind of performance you will get? I would think it would be quite different.
--
"Be blessed in your quest'' 89 764 (110K), '94 940T (180K) , '92 745T (totaled 2-10-05 RIP)

If you use a B230, you use B230 accessories and parts. The head fits the block as well as it fits a B234 block. You need a different timing belt tensioner.

The automotive B234 made about 155 hp. The marine version with 2.5L and dual carbs made about 170 hp. The marine version had half a point less compression, but it had higher lift and longer duration cams. I suspect most of the power gain came from the cams, not the displacement.

Power potential in turbo form is excellent. The B230 turbos had lower than stock compression. The non turbos made only 115 hp in USA form, and the turbo version absent the turbo would have made less due to the lower compression. Obviously if you start with 155 or 170 hp instead of 115 hp, and then add the turbo, the power will be greater.

There is still a limit to how far you can go without upgrading at least the connecting rods and the engine management.

Philip Bradley