B16B vs 4A-GE (BT) the factual and conclusive study

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B16B vs 4A-GE (BT) the factual and conclusive study

Now before you think that this is just another Toyota vs Honda brawl you might be disappointed.I have used the search function but the topics came up with replies like Honda is the best, thats why!

the purpose of this topic is to find out the differences in between these very similar engines.and why are they so different?

now we all know about the TOYOTA {AE111} 4A-GE (blacktop) 20 valves (3 intake valves per cylinder)(a total of 5 valves per cylinder) introduced in 1995 and continued till 1998, 1.6l (1587cc), a sky high Compression ratio of 11:1 , individual throttle bodies , OEM (factory) tubular exhaust manifold(extractors), lightened flywheel,six speed C160 gearbox on later models , this handsome brute manages 165 PS (121 kW 163 hp) at 7800 rpm with 162 N�m (119 ft�lbf) at 5200 rpm of torque. which is very impressive for a naturally aspirated 1.6l engine.

but turning our attention towards the Honda engineers, and the truly epic and unimaginable creation the much feared B16B-R. now this engine is based on a simple 16-Valve DOHC design with a displacement of 1595cc (1.6l)(basically a beefed up version of a B16A), a compression ratio of 10.8:1 and the people in charge of the B16B project at Honda managed to extract 136 kW (185 PS; 182 hp) @ 8200 rpm & 16.3 kg�m (160 N�m; 118 ft�lbf) @ 7500 rpm. Now from a 1.6's perspective if this does not seem much mind you a B16B has a higher specific HP output per liter than a Ferrari 360.

now coming towards my question and the subject of all this information is that
why a these seemingly similar for example both are DOHC/twin cam multi valve 1.6 with freakishly alike internal specifications for example look the Bore X Stroke of the two engines:
B16B bore X stroke = 81.0x77.4mm

AE111 4A-GE bore X stroke = 81.0x77.0mm
furthermore......
both employ their versions of variable valve timing control technology.

now on paper the 4A-GE looks like a winner with all the factory fitted race spec parts (like tubular extractors and ITB's for a road going car and the 11:1 CR surely looks like something out of a JTCC or Group A racing engine catalog)

Gari.pk User 6849 asked on 16 Aug 2010 12:30:01 pm

1 Answer

397 views |

Zubair - on 16 Aug 2010 12:30:32 pm

I've been pondering over these issues for quite a while as well. And I've unearthed a few interesting technical tidbits.

The 5 valve heads apparently do not give that much of an advantage over 4 valve types. Why, you ask? It's got quite a bit to do with turbulence. The problem with the three intake valves is that they are rather close to each other, and the flow from the adjacent valves is slightly choked where the valves are adjacent to each other. This is one of the reasons that Ferrari abandoned 5 valves technology with the F50 and the F355. Since the 5 valve heads did not give much of an advantage over the 4 valve heads.

The B16B is, if I'm not mistaken, a de-stroked B18 engine. This means that the connecting rod is much longer than a typical (or comparable) 1.6 litre engine, since the deck height (distance between the top of the block and the crank axis) is greater. This allows the connecting rods to stay more aligned with the piston's axis of movement and during the power stroke, the side thrust of the piston on the cylinder walls is much lower. This reduces the frictional losses and allows the engine to spin faster and lose less power in frictional losses.

A third factor is down to the valve actuation technology. VTEC can in theory, give you a high-RPM race cam coupled with a low-RPM road cam. The 4AGE cam profile stays the same over the whole RPM range. It's just the phasing that changes. There is only one cam lobe profile for the 4AGE VVT system. So, the Toyota engineers were obviously handicapped since they could not put in a race cam into their engine since the idle and low RPM qualities and emissions performance would've been horrible.

As an aside I suppose you know of the SR16VE N1 and the 4G92 MIVEC, what do you think of those engines?