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2jz Short block decisions

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3.8K views 26 replies 12 participants last post by  Jay Meagher  
#1 · (Edited)
I am at a crossroads and need some guidance from the group. The crux, I am trying to decide between a new 2jzgte short-block or a forged short block from somewhere like induction performance. I do have a complete 2jzge vvti engine that I've torn down to the block with the crank still installed. The short block will be paired with the NA-VVTI head. Here's the overall plan.

Stage 1: 500WHP on pump gas.
Stage 2: 600WHP-700WHP using better fuel, either race gas or race ethanol (no E85 in my area😭) and install a cam and springs

I'm thinking of running something like a BW 364.5 SXE on a tubular exhaust (for better sound), but I am very open to suggestions.

Short-block costs.

-A new GTE block from the dealer in my area is $2.9k and I could pick it up this week (called and confirmed availability).
-Professionally built forged engines are around $5k and there's one nearby for $4.7k that a profession engine shop has laying around (BC proH625+ rods, Traum pistons, balanced ect). The only downside with that is it's a 10:1 engine and with the NA-VVTI head, that brings static compression even higher. I would be ok with the higher compression if I could still run around on high 400's on pump gas on BW 364.5 SXE, but I'm aware that it narrows the safe ignition timing window and increases cylinder pressure.

This is going in a Mk3 Supa Turbo. As far as timeline, I'm hoping to do the swap in fall '25. This will be self-tuned on an EMU black with a knock listening device (tuner nerd pro). I have successfully tuned my 7MGTE and have taken HP academy courses. This is just context I'm providing so you guys can assess what I can handle.

Hoping for recommendations. New OEM short block or professionally assembled forged. Is the 10:1 engine a viable option?

I should have mentioned, street car.
 
#2 ·
Why not buy MAX or Eagle rods with Manley pistons, ACL or OEM bearings, and have a nearby machine shop size and assemble your GE block. You’d likely be a tad over the price of a new OEM block but have a better starting point on a setup that can handle an early torque curve (especially with the VVTi). Turbo oil feed isn’t an issue w/a GE when using the union bolt.
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#4 ·
I would choose one of your original options instead of buying random parts and hoping to find someone local that knows these engines, just to try to save a buck. Go with a reputable shop that knows 2JZ's.

A lot of people recommend having a Toyota short block thoroughly inspected for bearing clearances, etc, so add that to the cost. Or you can check it yourself.

Al
 
#7 ·
That's was a concern of mine with the new blocks. I was hoping to rely on the OEM quality and have the novelty of having a new block, but IIRC threads on here mentioned that professional engine shops noticed new blocks are sometimes not in spec, but I think that was years ago. Not too sure about the most recent batches. It's hard to believe that Toyota tecs would get that wrong but it's harder to believe the professional engine builders would lie about it or just be wrong. Anybody here have any experience with the newest OEM blocks?

To me, the whole point of buying a short block is so I don't have to check clearances. I have rebuilt 2 engines, and through that process I've found I would rather just pay someone to do the bottom end. So, tearing apart a new block, measuring clearances, and the potentially having to buy new bearings or change rings gaps ect is definitely a turn-off. If I'm going to pay a shop to do that work, I might as well have them do that work with forged parts.

Fortunately, there are some good machine shops and engine builders in my area. I'll reach out to them.
 
#8 ·
I just rebuilt a brand new OEM block that wiped the bearings out in less than 500 miles. My machine shop told me the crank was bent like .0025”.

For what it’s worth, I build and sell motors out of my shop. A stage 1 capable of holding 1000whp is $6500.
 
#12 ·
OEM shortblocks are a roll of the dice these days. Not sure what Toyota's doing but rumor has it they are no longer assembled or QC/QA'd in Japan.

10:1 is just fine. Run a thicker headgasket to get to your desired final static compression ratio, which if you're limited to gasoline I'd say 9.0:1 is about perfect with a VVTi head.

If you're on a budget, just find a set of good stock GTE rods and pistons, have the GE head decked to get rid of the quench pockets, and run ARP studs and a GTE headgasket and you'll be right around GTE static compression. That'll easily support 600-700whp on race gas or pump+ meth on a 364.5.
 
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#13 ·
Is quench something I should keep an eye on with running a thicker head gasket? Seems like a lot of 2jz guys ignore it and I've come across some threads on other forums about "softening up the chamber" with large quench is good for turbo and nitrous cars. If larger quench is fine, then I'll probably just pick up that built 2jz nearby with the 10:1 compression or even one of those blocks on the parts section here if they're still available.
 
#20 ·
I need a sanity check. Nearby engine builder has a GTE block in stock that uses off the shelf 10:1 pistons. I assume with my GE VVTI head, static compression would be higher than 10:1 with any reasonably sized head gasket, or just higher in general vs using a GTE head with any given head gasket. He is saying the GE head would bring static compression lower to 9.5:1 because the head chamber is bigger. Everything I've read says the opposite, chamber is smaller. Am I mistaken? I would hate to think this guy is wrong or worse, misleading me.
 
#23 ·
We plan to go to Induction or see if Jay(RS Garage) is building blocks yet. Both are local and will be refreshed and built to specific spec which is better than oem unless your core block or crank is no good. Then I would buy a new one.
 
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#25 ·
The block is thankfully in good shape and the crank spins really well, so there's a good chance I'm good there. I am seriously considering induction even though I'm way up in the north east. Their pistons seem really good from a layman's perspective.

RS garage's website does list short-block options.
His shop is fairly new but he did mention he offers the service with Mazworx when I watched his hour long Dart Block build. The screw in freeze plug option has m e interested. I'm sure Induction can provide it as well.
 
#26 ·
All right, measured the GE VVTI volume and Traum gave me the dome volume of their pistons. They were really fast to get back to me which was nice.

~41.9cc head combustion chamber
2.5 cc piston chamber
Head gasket+piston-to-deck clearance = .018

So that puts the 10:1 GTE short-block from the nearby shop at 11.65:1 compression ratio and definitely not anywhere 9.5:1. I know a thicker head gasket would drop the compression at the expense of squish, but it would need a very thick gasket. And, if I'm going to spend the money on a short-block, I really don't want to compromise on that. Just get the right pistons.

Last thing, I'm glad I checked the volume instead of trusting the nearby engine builder that my compression would be lower with the GE head. I avoided spending $5k on a compromised setup and know to avoid that shop.
 
#27 ·
Howdy guys, I am taking on orders for short blocks. I have 8.5cr and 10.0cr engines available. I'd like to keep it simple, if someone wants a 3.0 (stock stroke) I use a flat top and that lands right below 10.0CR. This is for the guys that are going to marry ethanol and not run boost on pump fuel. If you're going to beat on your car on pump gas I'd like to use 8.5 as it offers a wide margin of error in tuning before detonation eats up your engine and money! If you're looking for a stroker option I'm using BC cranks in 90mm/94mm and 96mm. I don't know if Induction/FFRE is set up for screw in freeze plugs. You'd have to call and ask. Thanks for keeping me in mind.