The Volvo OHC RedBlock engine was produced for over 23 years, from 1975 (OK, 1974 in reality) to 1998. Its first incarnation was the B21E (fuel injected) which launched with the 244 & 242 GLE, producing 122-129 DIN hp depending on market. Pretty much at the same time came the B19E for markets that favoured engine capacities under 2 liters. B21E/B19E we in a few months followed by B21A and B19A delivering 100 DIN hp and 90 DIN hp. A special version of the B21E was the B21GT that was put the 242 GT that was sold for just a year. It delivered 135 DIN hp due to H-profile camshaft and adjusted fuel injection. The 242 GT also had an aluminium rear axle, aluminium hood and trunk lid and a few other things reducing its weight to just shy of 1100 kgs, meaning wit was up there with the early hot hatches like VW Golf GTI etc. In USA we saw B21F in the late 70’s and early 80’s to comply with Californias rules for catalytic converters and the F moniker meant electronic fuel injection. Basically the LH Jetronic 2.1. In the early 80’s the B21ET arrived with a garret T3 turbo on its side, upping hp to all of 145 DIN hp. Not so impressing with today’s high performing 2-liters and even 1.5 liters from Volvo delivering 300+ hp for the 2-liter and 192 hp for the 1.5. Car enthusiasts soon discovered that it was quite possible to get quite a bit more out of the B21ET… by upping boost and shimming the injector pump. In 1982 Volvo also offered an upgrade kit for then then new B23A with a displacement of 2316 cc (2.3 liters) and 116 hp DIN that gave the engine turbo power, originally 140 hp DIN but many owners discovered that since it was blow through carbureted turbo-power, it was just to up the boost and the carbie said “OK!” and delivered more fuel. To a limit of course, but if you attached an intercooler 200 hp was no problem. The 240 GLT-4 got the 135 hp DIN B23E a few months later. Already a year earlier (1982) the 7-series debuted with 760, and the B23FT was introduced in the USA and Canada. It used LH Jetronic 2.1 electronic fuel injection and 155 hp DIN. It was a great motor with good reliability and character. It was though replaced after just Ione year with the B230ET that used K-Jetronic for the same power. This was together with the B200E and B230E with an revised engine block, the “low friction” engine, meaning skinnier rods, smaller rod journals etc in order to reduce fuel consumption. Early B230E/B200E had heaps of problems resulting in. low power and high consumption for quite a few customers. It was eventually resolved, but the low friction motor never made anyone happy really. We also saw B230A and B230K with similar 2-liter versions. This version of bottom end was produced between 1982-1988 as the 83 to 88A models. 240 received the B230 in 1985 onwards. From 1988B we saw the introduction of the beefier B230 bottom end. Emission laws throughout Europe and USA made it logical to ditch K-Jetronic (Mercedes hung on to K-Jet until 1994 I believe) and go for LH Jetronic 2.4 that used closed loop fuel correction and adaptation, something the 2.1 and 2.2 didn’t. The LH 2.4 equipped engines resolved a problem of durability among the turbo versions and changing back to almost the same crank design as the B23 engines and better rods (more goods and better profile) didn’t result in higher fuel consumption: with adaptive fuel injection the cars actually got slightly better fuel economy than the LH 2.2 and K-Jet cars. Also oils had gotten better and larger journals didn’t really mean more friction in the same way.
Heads: The Good, The Bad and The Ugly?
The head designs can be divided into two lines pretty much: those that are “swan-neck” and those that are not. the 405 and 531 are swan-neck and the 160, 398 and 530 are not. The 531 casting is the best, 160 the worst. 160 and 398 are found in B21 and B23 cars and the 405 are found in B21E/ET and B230ET cars, while the 530 are found in B230F/A/FT and 531 in B230FD/FTX (FTX Italy only) and some random FT engines. 405s come in two different castings; small and large cooling passages. You want those that are small passages. Those are the later ones and the change happened due to the earlier version was prone to cracking. The 531 is pretty much the 405 with the smaller cooling passages and no hole for K-Jet injectors. Plus some minor changes.
When picking your head, I’d start to see what comes with the engine you have got. And of course what you want to do with it. If you just want to turbo it to cram some more hps out of your engine with no absolute goal, sticking to what you have will probably work. As long as anything isn’t cracked or so that is. Even 160 heads will flow enough to produce 200-ish hp. Especially if you have an A, B, D or K camshaft you should be good. And that’s usually what you have in a head like that. Best of those is K, followed by A and then D and B.
If you are looking for more power and don’t want to bring the grinding stuff out, 405 or 531 is where you want to go. Especially if you are looking to up your power without adding a turbo. If you start off with a B21A, a 531, H-cam and “swan-neck” intake will take you you from 100 hp to somewhere around 130-135 hp. Quite noticeable. Have 2-3 mm shaved off the head to up your compression (405/531 have slightly larger combustion chamber than the other bunch) you might gain another 8-10 hp. Thats where the carburettor will limit you. If you have EFI and start with a B230F/FD, add the above components and chips like the VOC for fuel & ignition plus a 2.5″ exhaust and blueprint the engine you should be able to reach 180hp.