Tremenda colección de artículos de optimización de los M60 he encontrado en esta web: http://bmwv8capri.yolasite.com/ Realmente ganas algo puliendo y optimizando los conductos de la cámara de combustión? He quitado algunas imágenes porque superaban el límite de 15 unidades. 0-M62 Home Modifying the sump Exhaust manifolds Flywheels Engine mounts Gearbox choice Clutch ECUs Ignition system brakes m60-v8 specs Gallery Links Tuning the M60-M62 [photo courtesy of Vacmotorsports.com] Unfortunately non of the BMW V8 engines are well catered for in the tuning department. Tuning part companies focused on the M3 6-cyl engines and sell very few tuning parts for the V8s (excluding fancy tailpipes). Also these engines are seen as too complex to tune, which in the case of the Vanos-equipped versions is partly true. Which is a shame because apart from a few poor design features like the oil canister drain valve and the nikasil bore problems, it was has excellent tuning potential. The valves are bigger than any commonly tuned 16-valve 4-pot, and could support up to 120bhp/L if the cam lift/duration and intake/exhaust was redesigned accordingly. Because the M60/62 is eclipsed by the similar architecture 5L S62 unit used in the later E39 M5, few people have gone to the effort of tuning the M60/62 to it's ultimate specification. VacMotorsports in philidelphia build full race spec M60 units on demand up to 110bhp/L. In the UK Ric Wood Motorsport has built S62 units up to 120bhp/L in race spec. As a side - the 5-litre S62 V8 used in the E39 M5 was based on the M60/62 block but with a larger 94mm bore and 89mm stroke crank. It also came with individual throttle bodies as standard and a unique fly-by-wire computer controlled system that gave increased throttle response speed depending on the setting, along with continually variable cam timing on all four cams, it was a technical tour-de-force at the time. But it too was eclipsed by the new S85 V10, and then again by the latest twin turbo N63/S63 V8... [5L S62 V8 with modified airbox/trumpets in an E39 M5] After BMW introduced the original M60 V8 in 1992, it was quickly replaced by the M62 in 1995. The M62 is favorable for tuning because of it's larger 4.4L capacity, but it also has softer cams and a more restrictive plenum arrangement than the M60, the later M62TUB engines are equipped with the Vanos variable cam timing, which although clever can pose a problem for conversions if you move away from the Bosch DME ECU and want to find an aftermarket ECU that can control the system accurately. De-catted M62s with re-mapped ECU and improved manifolds have shown up to 340bhp, which shows the excellent potential of the engine design. Inlet system - The M62 plenum has slightly narrower intake runners than the earlier M60 design. The M62 was designed to have increased midrange torque, it has 310lb/ft peak at 3900rpm whereas the M60 is 295lb/ft @ 4500rpm. But both peak at the same 285bhp despite the M62's increased capacity. Enthusiasts have found that fitting the M62 with the earlier M60 plenum and cams will increase the top end power. Here the fatter runners can be seen on the M60 unit on the left. The nylon plenum on the M60 is fairly well designed and the only improvement i can think of would be to open up several spare manifolds and alter each of them with a slightly different runner length and bellmouth shape, and then dyno the engine with each different design. Beyond that and it would be a custom alloy plenum design with enlarged runners, or individual throttle bodies, which could be 2 sets of adapted superbike throttle bodies - [photo courtesy of Bodinecc.com, an Alpina 4.6 in a De Tomaso Pantera] Or fitting S62 throttle bodies with custom trumpets - [photo courtesy of Bodinecc.com] (the back of a De Tomaso Pantera leaves plenty of room for an excellent exhaust design, see bodinecc.com for more info on this conversion) Forced Induction The downside of the conventional tuning methods of fitting a shorter & wider inlet tract and big cams is that torque is often lost below 4500rpm. That's where supercharging and turbocharging have become very popular in the last 10 years or so. With digital mapped fuelling control it's possible to cater for big jumps to positive manifold pressure that was never before possible with carburetors. Modern turbocharger and wastegate design allows a well-chosen turbo to generate boost from far lower rpm than previously possible. Although fitting it all into an already tight engine bay could be tricky. Vortech and VF offered centrifugal blower kits for the M60/62 (although they were pricy) claiming around 400bhp for the M60 with larger injectors and 11psi boost which was an impressive gain on an otherwise stock engine. Given the space limitations, a single Garrett GT35 could be a good turbo choice and should spool fairly quickly. Similar sized turbo fitments on the smaller capacity M52/S52 straight-6 have given very good results. Cylinder heads - The valve sizes and position are identical on the M60/62 and S62. But the S62 had around 3mm greater valve lift. Which shows that that basic head design is very good as the S62 is making 400bhp from the same heads as the M60/62 On my M60 head shown here, i made some improvements to remove valve shrouding where the combustion chamber wall is tight to the edge of the valve, and to take off the lip at the edge of the valve seat insert fitting. There are also some improvements that can be made in the ports, mainly rounding off the cast lumps around the valve guide nose, and smoothing out the sharp lip at the back of the valve seat insert. This is the inlet port before and after - And the exhaust port before and after - With all 16 ports treated in the same manner there should be an overall flow increase, especially when combined with a better exhaust manifold design and system. Exhaust manifolds - Exhaust design has a big part to play and the standard 540i/740i manifolds are a space-saving design made from pressed steel panels with some kinks and flattened sections that can be improved on. The firing order on the M60/62 is 1-5-4-8-6-3-7-2 with cylinders numbered 1-4 from front to rear of the LH bank, and 5-8 from front to rear of the RH bank. On the LH bank BMW connects 1&3 and 2&4, and on the RH bank, 5&6 and 7&8 with very long secondaries pairing back near the gearbox. These pairs all have 270 degree firing intervals, and although not perfect it is at least an even connection of intervals. The main scavenging assistance comes from the secondary merger by the gearbox, where the long secondary length is tuned to the 270 degree interval so that the gasses from one cylinder are passing the the merger just as an exhaust valve is opening down one of the other primaries. And so given the space restrictions it's designed to give better midrange torque than any other feasible configuration. For torque gains over 6000rpm, a 4-1 resonance system would be the thing. But interestingly the 400bhp S62 in the E39 M5 uses a system of manifolds almost identical to the M60/62 and peaks at 6600rpm. They are certainly one of the first things to change in the quest for increased torque above 5000rpm. The manifolds i made up for fitting the M60 in the Capri were still compromised by a lack of space but i hoped they'd be an improvement over the standard design. The pairings are kept the same as the original design. Supersprint manifolds are (or were) available for the 540i and used a long primary 4-1 design which should assist at high rpm Dinan also did a very nicely designed set of equal-length 4-1 manifolds for the M62/S62 E39 but they weren't cheap! Given the high price of aftermarket manifolds i think it makes sense to make your own if the engine is going into a different shell. Cams - The standard M60 cams have 9.7mm lift on the inlet and 246 degree duration, exhaust cam is 9.4mm lift and 242 duration. Standard timing settings are: IO/IC 14 BTDC / 52 ABDC EO/EC 48 BBDC / 14 ATDC Overlap 28.00 degrees Some tuners have claimed to achieve more top-end power and a smoother idle by reducing the overlap to something like: IO/IC 0 BTDC / 66 ABDC EO/EC 54 BBDC / 8 ATDC Overlap 9.00 degrees But without seeing some dyno results i'm sceptical about trying that one myself. Beyond adjusting the standard cams, Cat cams sell a good range of different grinds for the M60, with up to 284 duration and 11.5mm lift on the biggest hydraulic follower cam. And then solid lifter race cams all the way up to 305 duration and 13mm lift. VacMotorsports also do a range M60/62 cams. Neither are cheap. Cylinder block - The main headache with the Nikasil and Alusil bores used in all the BMW V8s is that they cannot be rebored in the way that conventional iron blocks or iron liners can. Alusil bores can be re-honed if enough of the exposed silicon is left, but for badly scratched or worn bores fitting ductile iron liners is the only cost-effective way of restoring an alusil/nikasil block. For competition work no suitable forged pistons are available to suit the alusil/nikasil bore surfaces so most racers go straight for a liner arrangement. My M60B40 block was fitted with Westwood ductile iron liners by Precision Engineering Services in Inverness and honed to the stock 89mm bore: Some tuners have taken the bores out to 94mm (M5 S62 bore size) but with the added thickness of the liner this leaves a perilously thin amount of crankcase material remaining between the bores. This block is being machined prior to fitment of the 94mm liners: And the next step up in capacity is to fit the 89mm stroke crank and rods from the S62, but with all the expense it might make more sense just to start with a complete S62 motor... Pistons for the M60/62 seem hard to get hold of in the uk, in standard design or aftermarked types. Vacmotorsports in Philadelphia has a good range of race-orientated pistons from CP and Wiseco but they are all designed to run in iron (i.e. you need liners). The original piston part numbers for alusil and nikasil blocks is listed in Mahle's online catalogue but not available from any UK dealers. And if they were available the price would probably be the same as a set of forged pistons. Parts availability and cost seems to be the main problem with rebuilding and tuning the M60/M62. It's a great engine design, but bearing shells and full gasket sets are expensive, and the availability on some other parts is non-existent. Fortunately there are a lot of old motors floating around Ebay and scrapyards so 2nd hand parts are plentiful.