The best thing you can do to a 1JZ, is to install a 2JZ GE head, and make it into a 1.2JZ. -Short stroke, high flow head, 11,000rpm, 10:1 compression ratio, 800-1000hp.

I was blown away when I ordered a header flange for my 1J and when it showed up I thought the holes were cut wrong. Nope, they are that small lol.

I’ve had em all. The 2JZ GE non vvti is a bad bitch. I run the VVTI GE, the all around power curve is phenomenal. Done 1400 plus to the tire with 1000 torque. They are Torque monsters. Throw some aftermarket valves in them, some port work and it really wakes them up. Just a good bang for the buc. And like Dave said parts availability. Great Video. 👌🏻

The 1.5jz is just a replacement for a 1jz when they blow up. They aren't better than a 2jz, but when you have rod knock or Main knock from your 1jz, a 2jz is an instant upgrade in torque

I think another popular reason people put 1J heads on a GE block is so they can eliminate the fugly over the head intake that comes on the GE’s. Obviously I’m talking about IS owners that aren’t looking for record numbers. Hell I’ve considered it myself, but after watching this I will be going a different route, great video!

Over sized valves and an exhaust port would be awesome! To see on next video. You nailed it. On your points for the most part here! I encourage people to watch the whole video!

Would be interesting to see a video on the comparison of the 90’s Japanese ports… RB26 vs 2JZ vs VG30 vs 6g72 vs 4G63 vs 3S vs SR vs B-series

Makes sense to me to swap a 2JZ short block under the 1JZ head you already have set up, if you're not going for massive power. You already have EVERYTHING plumbed and rigged. A swap to a 2JZ head means a lot of replumbing that's unnecessary in many cases.

lovely, can't wait to see the results

I feel like VE can answer most questions when comparing engines. Would love a video on this topic specifically.

So because of the port location, the 2jz will always be better. Absolutely right about having your port straight as possible because it will need less boost to make power because of flow. No restrictions on flow. 1jz needs to make more boost to make more power than the 2jz because of the exhaust flow.

Loving all the new content 👌 ✨️

Hi Dave, I have a 1.5JZ in SC300 because the top end is from a Soarer. Switching the head to a 2JZ GTE VVTI is the goal, but the problem is the manifolds, and valve covers need to be swapped as well. If you’ve already got a 1JZ head, it makes the most sense to stick with it. Parts availability for the GE also seems to be a problem.

i love the 1jz for the sound and its designed by yamaha so it definately has a stamp of approval 💪🏾

the smaller 1j port helps the sound

Hi Dave, I've been a Honda guy my whole life. I've always felt the JZ heads sucked for airflow, obviously coming from the B series and K series, where they flow wonderfully. That being said I have a 1jz gte non vvti and this video was an eye-opener. I haven't put the work in yet but was aiming for 550 ish whp which seems to be easily doable. Thank you for this informative video.

Need to do a flow bench test with non vvti 1jz head next.

I see that the spacing on the water cooling ports are different on the Cyl head deck, I don't have Toyota engines, but out of curiosity, are block or cylinder head gaskets modifications needed with these different water port locations and shapes?

Never get tired of anything JZ

Thank you sir!

Been saying the same things for a very long time 😂 I think the major draw card of the 1.5jz is that it’s a special buzz word name, they used to cheap cheap here in Aus so a lot of people built them or wanted to build them

1JZ is oversquare so that might be why they made the exhaust ports smaller to increase low end torque, that's why people say the RB25 is a better engine because it is square it makes more low to mid range torque

Less volume for the exhaust gas to compress to spool the turbo, the only theory I see why the exhaust port would be smaller, also the exhaust ports aren't as important as the intake, overall great study!

400-600whp is the sweet spot for a 1JZ IMO; good balance between power and sound. Sky is the limit for the 2JZ on the other hand…😂

Thank you

What 1J head did you use? I’m interested to know if there’s any difference between the non vvti and vvti 🤔👍

Cost and ease of access (at the time 1.5J was popular) is the main reason people use a 1JZ head. No idea where the "it flows more" came from, but this was tested on a flow bench a decade+ ago on the forums

I done big exhaust port work on the 1jz vvti head last year on a 2jz bottom end made 1030hp on 6870

Hi there. I'm a JDM "tuner" who started building carb-turbo engines here in Japan starting around 1987, and still do stuff on the side to this day...although we've moved from carburetors to Motec, Haltech, etc... Anyway, I didn't watch the whole video (apologies), but I have answers for you. At first, it was a few people who already had a set-up 1J, and put a stock 2J block under it for the increased stroke. Some people saw this, and the rumors of the 1.5J being some kind of serious thing that made more power than just swapping in a whole 2J took off. Then the weaboos got ahold of it, and it became some kind of legend that was built with JDM Takumi fairy magic. Keep in mind that these are the same people who think parody like The Fast and the Furious (I only saw half of the first one) is a documentary. Anyway...long story short... It started with a few dudes trying to get some low buck (yen) performance gain, and ended with the popularity it has (had) for the same reason the FNF movie franchise did so well...because there are a lot of really fucking stupid people in the world.

Would love to one your ported engines compared to these stock ones. I can agree that a 1jz sounds better but not as good as a rb they take the crown. Most drift cars in Australia have moved over to the 1jz as you beat on it for seasons and reliable as.

Hey Dave great content as usual, so what do you think of putting a 2jz GE VVTI cylinder head on a built 1jz gte bottom end to offset the power potential just because you wanna keep weight and cc’s down. Can this work then I’m strongly thinking about it as I already have the complete engine in my mk2 Supra, and may think of reaching 800-1000 bhp reliably and safely with a bit of headroom maybe. 🤔

Would the 1JZ hold a higher exhaust gas velocity. Was thinking, if the intake flow was the same for both vehicles. The gas would need to go somewhere, so in theory would the movement of the away from the cylinder gas be more rapid for the 1jz? or is it neglegiable because flow>pressure?

I remember reading that toyota changed the head design on vvti 1jz vs non vvti. They made the exhaust ports smaller for low end torque. Might want to check out a non vvti 1jz. I know the non vvti 1jz's did not have any low end grunt.

My reason was cause i simply blew the bottom end and there was a cheap 2jz short block available that i could throw it all onto

Excellent video. My only concern with the 2jz-ge platform is ive looked and looked, but it seems like the only option to find a piston in 4032 that get an 8.5-9:1 compression ratio is going custom. Those aint cheap. Plenty of 10:1 options, but e85 is off the table for me.

Because I can have a fully forged 1.5jz for the price of a used stock 2jz. Thats why.

can you do a video on intake valve to exhaust valve ratio and what is your opinion. the 1 jz intake valve to exhaust valve is close in size but the 2 jz is far apart. can you give any insight to this as the advantage why toyota went this route

This is a very interesting comparison and interesting argument/debate. I personally built my 1.5j purely for parts availability. My 1jz head already has cams, springs and over sized valves and manifolds custom made for my setup and I grenaded the bottom end. Made the poor man's stroker motor a really viable setup for me. Allows me to use the extra capacity for a larger turbo. My current setup is over 1200hp. If you look at Goleby over in Australia they have consistently made well over 1200-1500hp or more out of 1jz gte engines complete. It's not rocket science it's been tried and tested time and time again. The vvti stuff is awesome because it allows you to move the power band easier but realistically most jz heads (1 and 2jz) making power are stock ports anyway.

i have a toyota aristo that’s available in 2jz-gte or 2jz-ge. i was only 17 so could only afford to get the 2jz-ge do you think with the 2jz-gte engine prices it’s worth me just buying another aristo but this time with the 2jz-gte?

If you have a 1JZ head, you're better off picking a turbo that's efficient for the RPM range your cams are optimized to, and simply enjoy the darn engine. That's why I have a naturally aspirated LS. It's a pickup truck, not a top fuel car, so I'm not trying to win the world. I want to build a 1.5JZ with a single G40 turbo in a replica of a 1930's race car, but with A-arm suspension. From 14PSI to 18 PSI, and a good cam choice, it should sound cool, rev to 6000-7000 RPM and be an enjoyable thing. People, you can't get overly competitive.

For fun flow bench a 7mgte to see how far the jz improves things... if they even did with the 1jz

Thats a 1j VVTI head and it does have smaller exhaust ports compared to the NON VVTI. I think it has something to do with vvti and spool for low end trq. Idk much but what im getting is a stock is300 block with gte rods and pistons can be a beast?

Sound is the biggest reason to run a 1jz head

High HP drag race or drift machine..2jz hands down. Street race and 500-600hp machine? 1jz more than enough plus the crowd loves 1jz screamer sound LOL..

How do the 2jz ge vs gte heads compare? Is the gte head the best option?

GE non VVTi has bigger intake ports than the GE vvti.

What would happen if you just opened up the exhaust ports on a 1jz head? I suspect that toyota deliberately kept them small to improve spool at low rpms.

So nothing can be done with the exhaust port?

If you do porting 2jz-ge, then this will already be a serious gap from 1jz

Can we do a sound comparison!!!

I have 1JZ-GTE VVTi head and i've made 6 intake valves 2jz-ge (33.6mm) + 6 intake valves 1jz- gte vvti (32mm)

Guys always say 1jz was built by Yamaha and is a better head. Most of them have a jdm car or didn’t go 2jz for 2jz price tax.

The wonky 1JZ inlet ports might be good for swirl? You’re right that the VVTI head is all round better though.

🇦🇬 ⭐️⭐️⭐️⭐️⭐️. 💯% concur. 🙇🏾‍♂️

I think mainly the reason that these swaps are done are for cost.. for a budget turbo for the longest time was parts availability and cost. when you wanted to boost your old thick rod 2jz SC300 or GS300 you could swap in the Non VVT 1JZ head as it was already single turbo with a forward facing intake and most of the sensors were plug and play. Now most of the thick rod 2j's have disappeared and you have to build a bottom end anyway, plus there are tons of ebay turbo manifolds and forward facing intakes for the GE heads so why wouldn't you build a 2jzge-nat?

Can I send you my Barra head for a minor port,rebuild and comparison to the 2jz !??

Need to flow the non vvti 1jz head as more of those are the 1.5

Do you have any experience with 1.2jz?

its true the 1jz does not flow as much as the 2jz but the 1jz non vvti head flows more on the exhaust side than the 1jzvvti. we have a 1jz non vvti making 1300hp, the 1jz vvti exhaust port is way too small imo

I would LOVE for you to do a 7m flow… that would put the 1jz 7m debate to bed.

Compare a 7mgte head to a 1j head?

it began as a cheap stroker for the 1jz when people blew up the 1j in their drift cars

Hi, Dave! I can bring you my 1jz non vvti to compare.

320 More to Hit 10k ❤🎉

So my 1jz is no good?

I would think 1jz would have a higher chance of valve float on one side

Nice to see actual real numbers get further public exposure! I don’t think you were too negative towards it, just stating visual facts. We made 1100hp at the hubs with a 1.5jz/7975/powerglide combo at 36psi. For which we are currently swapping to an 8082. So I certainly think that they have their place up to/around 1000hp if you already have all the supporting hardware in place and don’t want to change it all out. In saying that, we also have a 2JZ-GE head being built for the aforementioned engine when we want to step up to a proper sized turbo and actually go fast. 😅

🎙🎚

So does that mean a 1jz would rev even higher and faster with a 2jz ge head lol

2jz is a bad design, it cant even make 10,000hp.

1jz cameAfter 7MGte and the 2 after the 1 so yeah age

that is going to be very misleading for somebody who doesn't know enough about cams, 1jz and 2jz cams have to be reground to match. You can't just put 2jz cams on a 1jz head or vice versa

Dimpling porting intakes n top of pistons n throttle body butterfly n intake manifold

Why? Because the 2JZ that everybody really wants is bonkers expensive and unobtainium unless you're loaded. That's litterly 98% of the reason (the other 2 percent being contrarians). Blah blah blah justifucation justification, put 100 1jz/1.5jz/2jz in a room and set them at the same price and availability and you'll sell 98 2JZ before anything else.