Why 2JZ is so good?
Who made 2JZ engine?
The 2JZ engine has been made by and designed by Toyota. The 2JZ-GTE , the turbocharged 2JZ powered these cars :
- Toyota Aristo
- Toyota Supra RZ
Today we're going to dive deep into its anatomy to see exactly why it's so good and how it got its reputation.
When was the 2JZ made?
The 2JZ motor was introduced in the year 1991 and produced until 2002 in Japan.
How 2JZ works?
Let us start with the engine configuration : An inline six cylinders engine that's what the 2JZ is and all inline-6 engines are beautifully balanced because in essence an inline-six is two in-line three-cylinder engines which are mirror images of each other.
This means that in practice the primary and secondary forces within the inline-six are pretty much perfectly balanced and unlike some V6 engines which can suffer from a poor rocking moment between the cylinder banks,an inline six cylinder is beautifully, beautifully smooth.
This means that you can rev it higher longer and safer which means it's a perfect platform for increasing power. There's a Toyota engine that's very similar to the 2JZ engine altough it has 2 cylinders less. And that engine is a Toyota 3SGTE engine now it shares both the bore and stroke with the 2JZ and both engines are square by design which means they have the same bore and stroke.
Another thing they share which is pretty logical that they share it because they do have the same bore is the diameters of the intake and exhaust valves which are pretty decent.
Now in practice a square engine designs try to accomplish a balance between power and torque and the 2JZ is a really good example of an square engine that managed to do just that.
Next let's talk about the engine block, something that's very often discussed when it comes to the 2JZ engine and if you watch a video or read an article about the 2JZ you're almost always going to read something like this : the 2JZ engine block is extremely strong because it's a cast iron closed deck design.
And although this is essentially true it's an incomplete explanation because as we all know there's plenty of others cast iron inline six engine out there. But somehow the vast majority of them can't do what the 2JZ engine block can. To understand why the block is extremely strong we have to take a more detailed look at its anatomy.
And here we have a 2JZ engine block, now to understand why it's strong let's compare it to a different inline six cast iron closed deck engine block. A good example is the 2JZ's predecessor the 7M engine block.
This one is from a 7MGTE turbocharged engine and although the 7M is a good engine block and it can take quite a bit of power it can't take as much power as the 2JZ and looking at these two blocks what's the first thing that you notice?
Of course as you can see the 2JZ motor has a lot more reinforcement you can see these very large very pronounced reinforcement ribs pretty much everywhere on the 2JZ engine block.
On the other hand as you can see the 7M doesn't have reinforcement ribs that are nearly as pronounced as those on the 2JZ.
Now let's compare the 2JZ with the 3SGTE : one half does have the very pronounced reinforcement grips but the other one doesn't. The 2JZ as you can see has the pronounced reinforcement ribs pretty much everywhere.
What these actually are are oil return holes looking at the block from above you can clearly see that there is a lot of them which is good, oil return is a very important thing and if it isn't addressed properly in an engine and it is often overlooked you can have many different problems with your engine which can lead to pretty severe results such as oil starvation and other things when the engine is at full load.
The oil return holes on the 2JZ as you can see are outside of the main boundary of the engine block deck they have been moved outside for two reasons reason one is to leave more material more meat between the different passageways in the engine block.
More material and more meat is always a good thing because although it does increase the weight a bit, who cares about five kilos extra or three kilos extra when you're getting a lot more strength.
The second reason and resulting benefit of the oil passageway outside the boundary of the deck is that they have been used as reinforcement ribs some very large and very pronounced reinforcement ribs.
Again if you look at other parts of the block as well you will see even more very strong very pronounced reinforcement ribs and the 2JZ engine block is in fact one of the most heavily reinforced engine blocks ever to be manufactured when you pair that with a lot of material and the cast iron material itself you get something that's pretty much indestructible.
On top of that the main journals of the crankshaft and the main bearing caps are absolutely giant they are super fat and although they are not cross bolted like in some other engines they are still extremely extremely beefy and all of this explains why the 2JZ engine block can be taken to stratospheric power levels.
As if the block wasn't reinforced enough Toyota also designed a girdle which bolts to the underside of the block and then the oil pan bolts to this girdle and what the girdle does is that it ties together the bottom end of the engine block further reinforcing it and making it even stiffer and stronger.
On the top of the engine block we of course have the cylinder head gasket and this one on the 2JZ is a multi-layer steel head gasket composed of three layers of steel which was a big step up compared to the 7MGTE's fiber-based head gasket.
As expected the engine internals are very strong, the crankshaft features as we already said very wide very thick and beefy journals and is a fully counterweighted forged steel crankshaft.
The connecting rods are again surprise surprise very beefy very thick very meaty and are also forged just like the crankshaft the only instance of slightly weaker connecting rods are on the naturally aspirated late generation 2JZ engines that featured variable valve timing.
When it comes to the pistons : the pistons are not forged although many people try to convince you they are instead they are high pressure cast hypereutectic pistons and Toyota's quality control and production lines from the 90's are now topics of academic books so you can imagine that these are very very good pistons.
Even if these pistons are not forged they are very strong very well made and there's no inconsistency in the quality of these pistons.
So although they are cast they're capable of surviving 700 to 800 horsepowers on this engine and they feature both friction reducing coatings on the skirt and a thermal coating on the piston crown.
Another really interesting thing for the pistons is this hole right here this is actually an internal oil gallery and this is something only that the turbocharged 2JZ engines have and this is coupled with the oil squirters that you can find in the 2JZ turbocharged engine block.
And what the oil squirters do it is that they squirt oil right to the underside of the piston right into the oil gallery within the piston and what it does is that it directly cools the ground controlling temperatures and reducing the chances of knock.
Now some time ago Porsche released a important article and a scientific breakthrough when it 3D printed pistons and it boasted how these pistons feature these internal oil galleries that were made possible by 3D printing the pistons.
Well here's the same thing from Toyota in the 90's but there's an even crazier instance of this because Mercedes did internal oil galleries in the 70s.
So i like porsche you make really cool cars it's an awesome brand awesome cars but the internal oil gallery isn't that innovative.
The compression ratio is of course higher in the naturally aspirated engines but the very low 8.5 to 1 compression ratio in the turbo engines although a bit outdated by modern standards is still pretty useful because it allows you to safely crank up the boost quite a bit.
Now let us move on to the cylinder head.
The 2JZ again shares many things in the cylinder head with the Toyota 3SGTE engine. Both engines are true dual overhead cam design engines which means both cams are directly driven by a timing belt.
We have 4 valves per cylinder giving us a total of 24 valves for the 2JZ.
The valve encoded angle for the 2JZ is 45 degrees which is pretty wide and might even be considered a bit too wide for modern standards.
The intake ports on the 2JZ feature a more modern design compared to 3S engine especially to the first generation of 3S engines which featured Toyota's Variable Timing intake.
When it comes to the shapes of the intake and exhaust ports of the 2JZ, they are pretty decent and the 2JZ head does fall pretty well however there are some inline 6 engines from the same era that will outflow the 2JZ head.
And this is why when seeking significant power increases often beyond 800 horsepower it is often necessary to slightly reshape and the intake and exhaust ports of the 2JZ.
The 2JZ is a non-interference engine which means that if the belt snaps the valves and pistons will not make contact because the valves and pistons never occupy the same space in the cylinder.
This is nice but it also means that the 2JZ has some pretty mild camshaft specs as you can see we have some pretty mild duration and pretty mild lift and one of the easiest ways to start making more power with the 2JZ is to change the cams.
Of course when it comes to the valve actuation system we have some buckets directly on the valves and some shims for adjusting the valve lash.
So there's no hydraulic valve lifters in the 2JZ nor is there any rocker arms just a very simple reliable and easy to maintain system however it does to an extent limit the size of the camshaft you can run.
In a 2JZ motor the combustion chambers are a typical pen proof design with some pretty nice squish areas and as we have already said both the 2JZ and the 3SGTE feature the same intake and exhaust valve diameter sizes and these are pretty decent.
As we all know the turbo version of the 2JZ features sequential twin turbos and what this means is that it has two turbos one of which spools at low rpm and the other one joins in at higher rpm.
In the case of the 2JZ the second turbo joins in at 4000 rpm. Now usually sequential twin turbo systems feature one smaller and one larger turbocharger, in the case of the 2JZ both turbos are of equal size and were co-developed by Toyota and Hitachi.
The result of the sequential twin turbo system was actually a beautifully smooth power and torque curve the 2JZ is an incredibly linear and an incredibly smooth engine it's a joy to drive and on the street the horsepower are honestly more than enough.
And what i think is : We're forgetting a bit that with all the massive power builds and single turbo setups in the interest of obscene power and setup simplicity.
We have started to under appreciate the stock engine a bit, what's really impressive about it is that 407 newton meters of torque are actually already available from 1800 rpm you have to remember this is an engine from the 90's.
We have brand new engines with these sort of specs and the manufacturers can't stop bragging about it, which just shows you how good the 2JZ actually is.
The 2JZ is also one of the few cases of the rest of the world getting something more powerful than the japanese domestic market or JDM, in japan the 2JZ made 280 horsepowers.
In the rest of the world in Europe and in the USA it made 320 horsepowers.
This was because of that gentleman's agreement between the Japanese car manufacturers that we mentioned earlier.
What the gentleman's agreement was? It was an unofficial agreement between Japanese car manufacturers to limit the power output of there vehicles to 280 horsepowers.
This was done because Japan had quite a bit of car accidents in the 80s and 90's and everybody thought the main reason for this was that the cars had too much power.
Now in practice the cars had more power than 280 horsepower because although they were declared as having that much power if you were put to put them on a dyno you would see that they didn't really have 280 horsepower, they had a bit more but.
Why am i mentioning the gentleman's agreement because it's important to understanding why it's so easy to double the power output of the 2JZ it's so easy because the 2JZ came detuned from the factory.
Toyota didn't have a reason to push the engine to let's say 400 horsepower or whatever else, it was not profitable.
In stock form they couldn't make is such a powerful engine because again you could sort of break the gentleman's agreement by a bit but you couldn't smash it by making a 400 horsepowers engine.
The gentleman agreement is since long gone but it is the reason why many engines from this era had this sort of power output.
The second factor and a more important factor to the 2JZ's success and why it is so good at what it does is that it it's essentially as we know an overbuilt over engineered engine with giant safety margins.
There's a few reasons why it was overbuilt :
- One of the reasons was the global economic situation of the times.
- The other reason was the sort of reputation Toyota and some other manufacturers were trying to build back in the 90s.
You might remember this old ad from Toyota :
I remember it and i know that nobody seems to make ads like this anymore today's ads seem to be about the size of the screen in the new vehicle being released rather than the mechanics or the engine.
Nobody seems to care about that anymore and i guess times change, interests change.
But it's pretty obvious that engineers back in the 90's were told to build things differently and the entire Toyota engine lineup benefited from that.
The 2JZ perhaps most so it's almost like the engineers were thinking you know what somebody might take our car and our engine and do donuts in the parking lot for three hours let's make sure that the engine doesn't fail in that scenario.
Because if it fails the consumer will be disappointed and he will complain and this will negatively impact our reputation as a brand who builds very very reliable things so let's reinforce everything and make it stronger.
Compare this to the way modern manufacturers think is that they are going to hire an army of lawyers to protect themselves against the consumer instead of making better products.
Thinking like this is actually pretty naive and this isn't an objective way of seeing things.
Modern manufacturers have to abide by much more stringent emissions mpg and safety regulations and these mean that you cannot make heavy beefy bulky iron stuff anymore.
You have to make light, efficient stuff so your car and engine can abide by these new standards so you can sell it.
And why am i telling you all this ? i'm telling you all this so we can understand what the 2JZ is and why the new Supra didn't get a modern version of the 2JZ.
A modern version of the 2JZ cannot exist because the original 2JZ didn't have to meet these new emissions standards mpgs and all this sort of stuff.
It wasn't burdened by this and it was a product of a different time it was a product of Toyota from that time and today we simply live in a different time.
The tuning recipe for the 2JZ is so well known and has been executed so many times. I think by now everybody knows how it goes but this is an iconic engines article and we should talk about tuning so let's talk tuning :
Can you get 750 to 800 horsepower from his stock and open 2JZ? yes yes you can of course that's what earned the 2JZ reputation!
How do you do it?
- Get rid of the two OEM turbos with a big single turbo or if you want to be a bit more creative get two larger aftermarket turbos it's gonna give you the opportunity to have a slightly more interesting power and torque curve. But the big single is what everybody's doing so you should do it too because after all it's cheaper and it's a bit easier to tune.
- You're gonna need more fuel that means an aftermarket fuel pump and some larger injectors usually 900cc two 100 100 cc is gonna be just fine.
- You should replace the cams as well? You shouldn't replace the cams according to youtube because many people got 800 horsepower with the stock cams but it's going to be easier if you replace the cams with some cams that have a bit more duration and a bit more lift.
- Also you should stiffen up the valve springs for good safety measure.
- Next thing to do is get rid of the side mount intercooler and replace it with a big front mounting intercooler.
- Get a standalone ECU if you do not want to mess with some DIY flimsy wiring kit you can get something plug and play like AEM plug and play kit for the 2JZ it takes around 25 to 30 minutes to install and even a trained chimp could do it so once you installed it it's going to open up all the doors to tuning.
- The last step is going to be go to a dyno and that's it, 800 horsepower coming your way!
But who cares about 800 horsepowers that has been done so many times that such a small power figure! That's so lame haha ! Let's do 2 000 horsepowers can you do that?
Well of course you can but it is going to be a bit more complicated and a bit more expensive than youtube videos might suggest.
How do you get 2000 horsepowers from a 2JZ?
Well to get anything beyond 800 horsepower it's a good idea to open up the engine :
- You're of course going to be replacing the stock pistons with some aftermarket forged ones, something in the 2618 alloy which is super ductile is going to give you a big margin for knock and is going to be able to take obscene amounts of boost.
- You're also going to be replacing the stock rods with some aftermarket 4340 steel forged rods that are going to be even beefier than the stock rods the stock crankshaft can actually stay up to about maybe 1500 horsepower there are plenty of builds that are pushing these sort of figures with the stock crank.
- You're going to look at billet cranks only if you're interested in very very very high power numbers.
- The block is going to stay unless you want to be the world champion of drag racing in that case you're going to get a good block but then build a block means it'snot a 2JZ anymore.
- You're going to be replacing the turbo with an even bigger turbo to get obscene power it's going to be the size of half the engine and don't worry the 2JZ can take it because you put new forged internals in it.
- What you also might consider doing and what is the cool new thing to do is a compound setup that's where a small turbo is feeding a larger turbo and then the giant turbo stuffs all of that compressed air into the engine giving you an even more absurd power and torque curve compared to a big single.
- To feed all of this insanity you're gonna need even more fuel you're gonna need 12 injectors, yep that's two injectors per cylinder. Usually they're going to be approaching the 2000 cc range if you want obscene power.
- To feed the injectors you're going to need two probably even three fuel pumps, so you can imagine the fuel bill.
But you're not building a 2JZ for mpg of course.
So once you get into these sort of obscene things you're gonna be making absolutely incredible horsepower, the kind of power that can shame hyper cars that cost i don't know 100 times more than a 2JZ and all the parts that you stuff in it.
2JZ Engine Price
But again all this is going to be pretty damn expensive because the 2JZ is becoming expensive because it has become a cult, an icon, everybody wants a MK.4 Supra with a highly tuned 2JZ in it even people that own garages full of Lamborghini, Ferraris, Koenigseggs and whatnot.
They also want a mark for 2JZ highly tuned car because it's sort of the cool thing to own. Everybody wants this and of course this has driven prices up significantly for both of the Supra and the 2JZ.
As well as the aftermarket parts for the 2JZ some stuff in the 2JZ's aftermarket is actually really really overpriced often without a reason to cost so much.
But that being said the 2JZ aftermarket is probably one of the greatest global aftermarkets in the world, it has everything.
It's an engine blessed with an incredible, incredible aftermarket. There's a sea of manufacturers making pretty much everything for the 2JZ.
Everybody's making something for the 2JZ : from stickers and oil caps to billet crankshafts and build blocks it's all out there and if you have the money it can be yours.
So yeah that's the scoop for tuning the 2JZ basically if you have the money you can do pretty much everything. The sky is the limit for this engine and it is the definition of a modern engine icon.