The OHC engine is clearly superior to the earlier models

You wish. Most of the B21 & B23 heads have very sad intake ports compared to any B20 head & the exhaust port is barely any better. The crappy first gen aluminium head is really good for converting fuel in to radiator heat too, hence they had to use a larger radiator to cool the thing while making less power at the same time. The 405 & 531 heads rectified the problem, I wouldn't think about building up an B21 or B23 without one.

The other things that annoys me is the extra weight without any extra strength, the B23 has pretty flimsy bores too. Also, in RHD countries, the engine slopes the wrong way. Laying it over to the right for LHD cars is good, but it puts a lot of extra weight in RHD cars on the right front tyre.

The valvetrain in particular is a major advance

I like the cam, I’d like to saw the top of the head off & stick it on top of B20. The crank is a a little stronger too. The rods are a bit of backward step, the only reason they made them bigger was to compensate for the lower material spec & the lack of heat treatment. The big counter bore for the head of the rod bolt weakened them a lot too. I think they intended to use capscews in them, but decided to cheap out & use the bad bolts instead.

capable of running for hundreds of thousands of miles with no attention whatsoever. Try that with a B20.

It’s not hard to make a B20 cam last if your cam grinder knows what he is doing. Most of my road cams go for years in between valve adjustments, but I’d still like to have the OHC layout.

As for horsepower, there are several variants of both OHV and SOHC engines, and they range from approximately 90 to 135 HP for both types

The proper B23E with the K cam in it makes about the same power as a B20E, but they guzzle a lot of fuel to do it. The OHC K cam is fairly HUGE compared to the OHV D cam, a B20E would be up around 150+HP of the same size ponies if you use the same sized cam.

The strut front end is much easier to work on, and requires a lot fewer parts for a complete overhaul.

Yes. That makes it cheaper, but that doesn’t make it better. It is easier to make a 240 front end ‘handle’ & turn in, but they eat tyres to do it.

The rack and pinion steering that comes with it is also an improvement over the worm and roller box, idler arm, and six (!) tie rod ends of the older models.

There’s nothing wrong with the 140 steering layout except it’s slow. It’s the other half of the reason why 240’s eat tyres compared to the 140’s (or 120’s or P1800’s)

240 rear end is more durable than the 140, but it gives up a heap of traction. If you want to turn a 140 in to a burnout machine, just fit the 240 rear in to one.

I will agree with you about the appearance of the cars---the 71-72 version of the 140 was the best.

I don’t particularly like looking at the 140 either, but I’ve always preferred function, so I prefer the early dash because of the extra leg room. If I wanted a Volvo to just look at, I’d buy a P1800 or even a 120, but what I like most about the 140 is it’s practicality & it’s indestructibility. My town & shopping car park beast is a ’73 140 with a B20A in it. We’ve had it for nearly 4 years & I haven’t changed the oil or filters on it. About every six months the oil pressure light comes on when you hit the brakes, so I open the bonnet & add oil & water to it. The thing does 24 imperial MPG around town with a BW35 left in 2nd gear, so as much as I hate how slow it is, it just won’t die & I rarely put spanners on it.

The thing that irritates me the most about 140 & 240 body is the dreaded whistling sound. That showed up around ’73 with the arrival of extra knick-knacks around the front & I don’t think they ever got rid of it again. The 240 has more drag then the early 140 too which would of seemed hard to do, but Volvo managed to pull it of somehow!