If you want to learn about pepping up an old redblock Volvo, Turbobricks.com is the forum to learn from.

The reason I got the late model B230 donor motor is because the last iteration of the B230 had piston oil squirters installed, these keep the piston temps down. I think the main reason Volvo put those into the motors was to allow them to run tighter piston clearances (less thermal expansion to account for) - because they'd been getting customer complaints about piston slap noises on cold engines for a while. But in a turbo engine - keeping the pistons cool is a really good thing as it helps prevent detonation. Of course, you can put squirters on any engine, but might as well get one from the junkyard with them already in it if you have a choice.

Running through the engines backwards in time:
93+ B230 - Has the stronger rods, has oil squirters. Distinguishable from earlier B230's by the timing belt - rounded teeth on the belt and gears.

89 - 92 B230 - Has the stronger rods, *might* have oil squirters? - apparently Volvo put squirters in some of them, but it's spotty. Distinguishable from earlier B230's by having large cats in bumps along the oil gallery on the right side of the engine - to make room for the oil squirters, even though they didn't install them as standard for another 3 years. And distinguishable from later B230's by the square toothed timing belt teeth.

85 - 89 B230 - The 'efficiency' engine? In any case, whatever Volvo was after they used weaker 'skinny' connecting rods, and a center thrust bearing. Just a somewhat weaker motor design. No problems in the turbo cars, at stock boost levels. But try to hot rod one of these and you're on thin(ner) ice. Get the tuning wrong, ping it a little under boost, and you'll likely bend and break a rod or two.

83 - 85 B23 - in some ways purported to be the strongest motor (all stock components).

As for the transmission - The M46 (4 spd OD) and M47 (5 spd) are both pretty much identical internally - gears 1-4. Same design, just the M46 hangs an electrically activated OD on the back end, and the M47 has a more compact 5th gear in a housing bolted on the back end. Both of them, however, share a weak 3rd gear. 3rd gear resides at the end of the output shaft, farthest from the bearing support on the back side of the case, and more dependent on the support from the input shaft. With some miles on the bearings, this just allows 3rd gear to push away from the layshaft a little more when under torque - and this will eventually lead to a failure. A very rough ballpark HP figure (gleaned from numerous failures among the turbobricks crowd) seems to be 225 HP.

Not hard shifting, just full throttle in 3rd gear. Vrooooomm*gigantic metallic Velcro ripping sound*... Car made it back home as a 4 speed, though.

Automatic AW71 transmissions can handle more power, I just swapped mine out early on because I just like driving a manual. Even if it was faster with the automatic (no lifting during shifts - the boost continues unabated). As you go up past 250 hp or so, you might need to tinker with the valve body some - the fluid accumulators that smooth the shifts start placing stress on the trans internals as they try to smooth shifts on that much HP by slurring the shifts slightly. Disabling the accumulators makes the shifts more abrupt, but saves the clutch packs.

Rear axles are fairly overspecced in Volvos, the main limitation on their life span is the traction of the rear tires. Get sticky enough tires on a normally aspirated 115 HP car and dump the clutch hard enough, you can break it. Conversely, leave normal tires on your 450 HP beast motor and you'll have trouble launching it without spinning, but the axle will survive. So in vague terms, at whatever point you find yourself contemplating some slick drag tires, you might need to be thinking about how to get your car home afterwards when the rear axle grunches.

A 93+ 940 turbo would have the nice engine already in it, a couple of down points for me are that they only came with automatic transmissions, and the rear suspension is a little weaker on them (instead of the stout 4-bar of the 240, they have a center mounted torque beam that can bend). And just from a style standpoint, I like the 240's looks more than the 'where'd my french curve go? Oh well, I'll just use this straight edge' styling of the 700/900 cars.

The HP level of the car is, however, one of those goals you'll repeatedly arrive at, then see it recede again. When I first got the car, it probably had 140, 150 hp, felt nice and peppy. Then after a few months, I wanted more. And each time I made it faster, I'd be at first again impressed, excited, then gradually just used to it and wanting to go a little faster. Currently, it's a bit brutal - the engine is a little peaky and the power comes on in such an intense shot that you can only use it in little tiny bursts on public roads. But it's still perfectly fine in 'daily driver' mode - the electronic boost control only kicks it into full-tilt mode when the pedal is all the way down, avoid that last bit of pedal travel and it acts like a perfectly sane 160, 180 hp car.

The upcoming projects of mine are just sort of completing steps. The 16V engine was initially built with a few shortcuts, just to get the car on the road and driving. I think once I get the last few things done I'll finally be content and happy with the car and stop fidgeting with it.

hah
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'63 PV544 rat rod, '93 Classic #1141 245 (now w/16V turbo)