Honda J30A engine

1. Specifications
2. Overview, problems
3. Performance tuning

Honda J30A engine specs

Honda J30A engine reliability, problems and repair

In 1997, J30A engine was launched with the displacement of 3 liters. This is a typical 60° V6 engine with a compact aluminum cylinder block, its bore spacing is 98 mm, and the deck height is 235 mm. Inside this block, there is has a crankshaft with the stroke of 86 mm, 162 mm connecting rods and 30 mm compression height of the pistons. This provides the displacement of 3 liters.
This cylinder block is covered with two 12-valve SOHC heads. These heads use 34 mm intake valves, and 29 mm exhaust valves. The J30A is also equipped with a variable valve timing and lift electronic control system VTEC.
The camshafts are rotated by a timing belt to be replaced after every 60,000 miles. Don’t underestimate it, since if the belt breaks the valves will be bent.
In addition, you should adjust valves after every 25,000-30,000 miles. Here are the valve clearances for a cold engine: 0.2-0.24 mm for intake valves, 0.28-0.32 mm for exhaust valves. The J30A engine uses 240 cc/min fuel injectors. The firing order is 1-4-2-5-3-6.
The diameter of the throttle body is 60 mm.
Based on the J30A engine, a while family of J engines was developed: J25, J32, J35 and J37.
This 3 liter engine was manufactured until 2007, and then it was replaced by the popular J35. Today, you can buy an Acura RDX in China, and it will be fitted with a J30Y engine. This is the only version that has not yet been discontinued.

Acura J30A engine modifications and differences

1. J30A1 is the first modification of the engine, here the VTEC is activated after 3,500 rpm. The power was 200 HP @ 5,500 rpm, the torque was 264 Nm @ 4,500 rpm.
2. J30A4 – this engine uses new pistons (compression ratio 10), the intake valves diameter was increased to 35 mm while the exhaust valves were not changed and remained 30 mm. There was also a modified VTEC system, a new intake manifold, an electronic throttle body, and a new exhaust manifold and exhaust system were installed. These mods were successful, and the power increased to 240 HP @ 6,250 rpm, and the torque to 286 Nm @ 5,000 rpm.
3. J30A5 was the analog to J30A4, its power was 244 HP @ 6,250 rpm, the torque was 286 Nm @ 5,000 rpm.
4. J30Y1 was a modification for the Chinese market. It was installed in Acura RDX.
5. JNA1 was a version with an electric motor made for Honda Accord Hybrid. This engine reached 255 HP @ 6,000 rpm, the torque was 315 Nm @ 5,000 rpm.

Acura J30A engine problems and malfunctions

These engines often have problems with unstable rpm. To remove this fault, it is sufficient to clean the throttle body or the EGR valve.
As to the rest, J30A are good and pretty reliable engines, but all of them are very old, and they have run many thousand miles. All this only means that you can face problem at any time. Do what depends on you: regularly perform maintenance of your engine and use good quality engine oil.

Honda J30A engine tuning

Let’s get your dead J30A1 engine to go a bit faster than right now. You will need the following performance parts: cold air intake system, a J37A throttle body, J30A4 pistons, a J32A2 head, a J32A2 intake and exhaust system. To make such a J30/J32 hybrid work properly, you have to configure the ECU, install headers and a 2.5″performance exhaust system.
All these mods will increase the power to 270-280 HP, this is the optimum price-to-quality ratio. You can look for some performance cams, install high compression pistons, or do other upgrades, but it is not worth the money.
You may avoid spending your money for what is described above, and just purchase a supercharger kit that will give you about the same horsepower. If that’s not enough, then build a J30A/J32A hybrid and install a supercharger kit. This will definitely be enough. It makes no sense to go even higher, you will need forged internals, a turbokit, and a lot of other components.

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