I need to know. What are the specs on this Frankenstein motor. What is the real reason that people do 1.5jz build ups? I gave it some thought and it i can understand if you already swapped in a 1j and your bottom block blew and you just swap in a 2jzge block for cheap instead of a rebuild or trying to find a 1j block in America and the extra benefit is the .5 liters and a lil bit higher compression. But some ppl swap in a 2jzgte bottom block but why not the whole motor? And others go 1.5jz from the get go. Why? I've heard rumors that the 1j head flows better than the 2j head? Is it true? So is a 1jz head, 2jzgte bottom bock the ultimate supra motor? I just see alot more build threads with 1.5jz and not full 2jz and need some answers.
the truth about 1.5jz
- Thread starter queenskid926
- Start date
I had a 1jz. I bought a 2jz block and swapped it for my 1jz block. I kept my 1jz head because I already had a new Drewgo manifold and 1jz cams. I don't know for a fact which head flows better, but Ilove the combo that I have now. The 2jz block does help a lot with low end power, but my 1jz was no slouch. I made 543rwhp @ 24psi with my 1jz. I've yet to dyno the 1.5 at 24psi to see what the difference is going to be. I may dyno in a week or so to find out though.
thanks for the quick response. which 2j block do you have swapped in? turbo or non turbo? cant wait to see the results of your dyno and see what the difference is. when you go to the dyno, the only thing different would be is your block correct?
suprahero;1092421 said:
I have a 2jzgte block, but many many people have did this swap with the ge block. They end up adding a oilfilter sandwhich plate or something like that. It has an oil feed for the turbo on it.
I completely rebuilt my motor before I installed it, but I used the stock 1jz gasket. My compression was a little higher than I needed it and I ended up blowing the motor up in about two months. Before I did, I dyno'd it and made 517rwhp at 17.5psi. On the 1jz, I made 453rwhp at 17psi., so I gained about sixty rwhp with the extra half liter.
I completely rebuilt my motor before I installed it, but I used the stock 1jz gasket. My compression was a little higher than I needed it and I ended up blowing the motor up in about two months. Before I did, I dyno'd it and made 517rwhp at 17.5psi. On the 1jz, I made 453rwhp at 17psi., so I gained about sixty rwhp with the extra half liter.
No, the 1JZ does NOT flow better than the 2JZ head. It does however have higher intake gas velicities due to the smaller intake ports, and slightly smaller diameter runners, giving you a little bump in low-end torque.
The 1.5JZ isn't better than a full 2JZ however. The only reason most people do it is so they can keep their existing 1JZ turbo manifold, and possibly for the sleeper look. I actually bought a complete 2JZ motor, so I can go full 2JZ in the future.
IMO, the 2JZ head has a better designed combustion chamber anyways. If I had a 2JZ turbo manifold, I would put my 2JZ head on.
The 1.5JZ isn't better than a full 2JZ however. The only reason most people do it is so they can keep their existing 1JZ turbo manifold, and possibly for the sleeper look. I actually bought a complete 2JZ motor, so I can go full 2JZ in the future.
IMO, the 2JZ head has a better designed combustion chamber anyways. If I had a 2JZ turbo manifold, I would put my 2JZ head on.
Rob, what benefits do you expect with the exact same setup except for the 2jz head? Do you have any idea how many more horses you'll attain, if any? I'm just curious. I don't have a 2jz head but I was thinking about starting to aquire parts for a full 2jz build.
I always thought people did 1.5 swap so that they do not have to deal with the 2JZ wiring. 1JZ head and electronic is easier to do isn't it?
Why I went with a 1.5JZ ?
I had a 1JZ and loved it.
I had a 2JZ in my car and loved it even more. Like Jay said, that extra .5 liters does provide that extra low end torque and is great for my style of driving. Mostly commuting in my car. I don't have to keep shuffling through gears everytime I slow down
Another reason I used the 2JZ block is because I know I can convert it to a 2JZgte anytime I feel like it. For know I have the 1JZ stock turbos and Aristo /2JZ wiring setup on my car so the move to a full 2JZgte will not be a big hassle. I love my current setup as it gives me best of both worlds...low end torque qith quicker spooling twin turbos.
I had a 1JZ and loved it.
I had a 2JZ in my car and loved it even more. Like Jay said, that extra .5 liters does provide that extra low end torque and is great for my style of driving. Mostly commuting in my car. I don't have to keep shuffling through gears everytime I slow down
Another reason I used the 2JZ block is because I know I can convert it to a 2JZgte anytime I feel like it. For know I have the 1JZ stock turbos and Aristo /2JZ wiring setup on my car so the move to a full 2JZgte will not be a big hassle. I love my current setup as it gives me best of both worlds...low end torque qith quicker spooling twin turbos.
nice so when im fiish going 1j, i can just pull the 1j out and drop a 2jzgte in and run it off the 1j wiring? anything custom to do to make it work?tissimo;1092660 said:
suprahero;1092516 said:
I'm not sure how different it's going to be. I'm going to assume there will be more top-end power simply due to the larger intake valves on the 2JZ head. I also expect more timing advanced due to teh combustion chamber design. I have this feeling spool will be sacrificed slightly with the slightly smaller exhaust valves.
As for wiring, the two motors are almost identical wiring wise.
i went 1.5j cause i had a 1jz in the car and crank walked the block so found a 2jzge and modified the block but used alot of the 1jz stuff... oil pans sensors and of course everything on the head... port matched and polished head along with 1mm oversizing the valves... all in all even untuned this car hauls ass just need to get some other electrical issues fixed and the car tuned
just need to get some other electrical issues fixed and the car tunedJust the mirror the thoughts of the previous posters, from what I can understand there isn't any particular benefits to running a 1.5jz setup unless you already have a spent a chuck on headwork for the 1j and then had the bottom end eat itself.
It seems the swap is done out of convenience rather than for performance, So if you're starting from fresh (i.e, don't have a monster 1jz head lying around) the 1.5jz conversion seems a bit pointless.
It seems the swap is done out of convenience rather than for performance, So if you're starting from fresh (i.e, don't have a monster 1jz head lying around) the 1.5jz conversion seems a bit pointless.
DonS1mpson;1104516 said:
if you dont know what your talking about :: IJ. ::
i would say the swap is worth it you get a lot more mid range power.
and as for the cylinder head
1jz is better for low / mid range you will spool a larger turbo faster with a 1jz head then a 2jz head.... 2jz head youll have more top end power but when you think about it how many people are going to make 1xxx rwhp and max out the 1jz cylinder head??? very few people.
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well considering you can get a 2jzge block for quite cheap and then get it built for high horsepower, why not just use your 1jz head that you probably already have an exhaust manifold, nice single turbo and more aggressive cams put into? just replacing your manifold with a 2jz one and cams for a 2j head will be far more expensive then getting the longer timing belt, serpentine belt and other small parts to mate the 1j head to the 2j block.
specifically going out and building a 1.5jz from the start? maybe not all the efficient on your wallet, but neither are these cars, do whatever the hell you want
specifically going out and building a 1.5jz from the start? maybe not all the efficient on your wallet, but neither are these cars, do whatever the hell you want
If you are concidering a 1.5jz off the bat, just go 2jz. In the beginning, you either WANT the 2.5l block or you want the 3.0l block. Both can be taken to the same power levels, it is just what you want to build, and where you want the power.
foreverpsycotic;1104847 said:
There is quite a big differance in price to justify a 2j over 1.5......