1JZ VS 2JZ Tear down and Differences - THE SKID FACTORY

Today on The Skid Factory Al & Woody head up to Goleby's place to tear down some JZ Engines and talk about some key differences.

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Please note: We like to make interesting car mods and show you how we've gone about it, but we can't promise that anything we show you will work for your particular car, or that you won't harm yourself, someone else, your car or your warranty doing it. Please be safe, be responsible and unless you know what you're doing, do not fool around with very serious machinery just because you've seen us make it look so easy.

[theskidfactory]

We’re just a couple of dickheads making observations while pulling apart engines. If you have something to add then let us know below but please don’t be butthurt if your an RB lover..

[Quetzalcoatl]

Woody's a top bloke. He took the time to make sure the audience has enough to understand, asking questions to get things straight and getting them to actually grab and show examples.

[woopimagpie]

Never ceases to amaze me how people will ask about something because you are the expert, and then argue with you when your answer doesn't line up with their opinion. I'm glad I have a term for those people now. Thanks fellas. "Askholes" is perfect.

[stealthynipz]

id like to thank The Skid Factory for the shout out. cheers mates!

[Elxmo]

Need more Goleby, every time he pops up he's good value.

[nunoribeiro]

Anyone noticed that Christian looks like long lost cousin of Nik Blackhurst from Bad Obsession Motorsport? I was expecting him to start talking about brackets! xD

[ijsbrand_JZ]

A 2JZ-GE-Turbo build by you guys would be awesome! <3

[julianbrecciaroli]

Yeah but my mate Kyle, his dad’s cousin reckons he has a prototype 3JZ and it’s good.

[shaneomacgardner]

Compression ratios plus cam opening and closing timing can change the needed valve sizes, at higher compressions energy is extracted more efficiently before bdc so the exhaust can be opened earlier. This allows a smaller valve to flow the same volume because it has longer to do it. The big benefit is then more room for larger intake valves. Dunno if that's what is happening here but I'm sure Toyota weren't silly about it :-)

[efandapp]

Yes! Finally some 1J/2J content!
-JZS171 Crown owner

[fknmillsi]

Thankyou for getting the pronunciation "Jay ZED" correct!!!!

[nickmcgarvey]

I have a 1JZ GE!
Bought it super cheap after digging through all things JZ for sale. It's under the hood of my 1982 Celica Supra.
There are many variants year to year and car to car, they all have different harnesses (harni) and ECUs.

[Dannyvirk]

The reason for differing sized diameters of exhaust valve across the 'Jizza' series of engines is because of pioneering work in four stroke cylinder head fluid dynamics by Robert W. Faid of Greenville, South Carolina. His work using some of the first computer simulations of air flow in an engine, and his subsequent discovery of 'Brownian motion', giving him his second Noble peace prize, showed i've forgotten where I was going with this.

[aserta]

I have a friend in France who has been importing 2jz engines for 3 years now. I think he has about 14 or 16 of them, and a ton of parts. He's developing a new hill climb race car (unsure if they are really race cars) and the amount of broken parts and things, is astounding. Some people take racing for granted, but the reality is that once you pass the newb stage, things get really, really pricey.


All that jamble said, 2jz engines are really nice. I've gotten a new appreciation of the product once i got to wrench around one whilst helping. Initially i was kinda meh, mildly impressed, but once you go in its guts, you really see the various things done to make it a structure stable engine AND why it's such a loved platform. Kinda reminds me of old German engines in a way, obviously with age and tech differences.

[joannaatkins]

**Theoretically** the longer the stroke of an engine, the further the piston rings have to travel in contact with the bore, which increases both the speed of the piston and the potential wear of the piston rings. If the engine is oiled correctly this makes no real difference, but it is something academically interesting.

Again, **theoretically**, a short stroke engine means you can rev higher (F1 engines have a very short stroke) because you have X amount much less distance to travel per engine revolution per piston, so less speed for the rods and pistons (because travelling 70 something mm verses 80 something mm in the same amount of engine revs) and less friction for the piston rings. Of course this means the rest of the engine needs to be able to support faster revolutions before the potential gains could be utilised.

The extra speed of long(er) stroke engines like the 2jz means that, again **theoretically**, the piston and rod bearings have more inertia to overcome per stroke, due to higher speed, meaning **theoretically** more wear on said bearings. Again with correct oiling this is no issue. The extra inertia created due to the faster speed means that torque figures for a longer stroke engine should **theoretically** be higher, all things being equal. This is often why very high revving engines produce incredible peak power, but lower torque than many people expect. This is also why stroker engines don't produce the power people expect, but incredible amounts of torque.

You will often find that in two equivalent engines with similar technology and the same displacement, the one with the shorter stroke will be the more fuel efficient. This is because it has less inherent need of fuel/combustion power to overcome the inherent inertia, so also less torque but better efficiency. That being said, a larger bore also means that there is **Theoretically** more friction overall, because the piston rings have to wrap further around the piston due to the larger bore.

This is all extremely academic, because every engineering decision is a balance between competing forces. Engines are just fun ways to explore how energy is transferred, used, wasted etc.

Interestingly all of this was and is known by Toyota engineers who know a little about designing an engine, so it makes naff all difference because both 1 & 2J engines are excellent and excellently designed. But from the standpoint of "Oh, that actually makes sense" that is the difference stroke makes.

[jamessouthern]

Could listen to Al talk to people in depth car stuff all day, need more like this

[DavidH]

I’d give all the money to follow Al around so I could watch him call out bullshit in the span of a single day.

[TheBrokenLife]

_The 2J is clearly better, because it goes to 2._ ~Nigel Tufnel

[andrewc]

Obviously, Toyota realized that the 1J's larger exhaust valve was getting in the way, they fixed this in the 2J

[fredericrike]

You did draw a crowd, dint ya"! Great comparo- I'm not strongly knowledgeable about modern Japanese engines, so there was lots to see and learn something. Al, you and Woody are getting pretty good at this- Christian stated out a bit quiet at first, but as the details started flowing his brain kicked in and provided a great counterpoint. Bravo!