- Toyota's 2JZ has been one of the key products or key engines in the sport compact market and
as time has gone by, people, particularly drag racing this engine have been making more and
more power, upwards of 2500 horsepower but at some point the factory block says no more.
The strength of the factory block obviously has limitations and in the last decade, we've
seen a lot of drag racers move towards the billet alloy block but that also comes with its own set
of pros and cons.
We're here with Mike from Race Winning Brands to talk about Dart's brand new just announced
cast block for the 2JZ so for a start, it's probably worth mentioning that at the time of this
recording, it's not quite ready for release is it, we can't actually buy one of these?
- Yep correct.
- But it is coming?
- Yep we're in pre production right now, tooling and castings are going through and then Q3, Q4
of 2023 is when we should be able to start shipping product.
- OK let's start by talking about the weaknesses or problems with a factory cast 2JZ block,
what was the impetus behind this particular product?
Yeah so there's many failures on a factory block, depending on the power level.
Anywhere from deck cracking to crank case cracking, main saddles pulling out so we kind
of took all that and just benchmarked where are we seeing failures and then basically worked
from our model there and just tried to improve 'em step by step by step.
- One of the big things with the 2JZ, at a certain power level, obviously arguable as to what that
power level specifically is but let's say around 900 horsepower, the factory cast caps tend to
fail so of course the aftermarkets come to the rescue there, there's a number of companies
making billet caps already, how have you dealt with this with your new cast block?
- Yeah so the main area on ours, we went from a traditional, how the OEM block is a 2 bolt main
and we've actually changed the main structure around to fit a four bolt cap in with a 12 mm
and a 10 mm main stud and that allows us to, just that much more clamping force on that main
area and spread that load for the larger power adder, larger cylinder pressures.
Safe to assume you're also using a billet cap as part of this?
- Yes sir.
- OK in terms of other weak points on the 2JZ block, deck surface, deck surface thickness,
bore thickness, where are the other problems?
- Yeah so we've seen a lot of cracking through the deck and that usually comes from over
torquing the heads.
Well to combat that, we added deck thickness, factory block's around 200 to 300 depending
on the casting and the core shift, where ours is set at 750 thousandths.
And that allows us to have a lower clamping force on the sleeve and keep that deck surface
as true and flat as possible.
- So essentially this is going to help with head sealing at higher boost pressures?
- Very much so.
- Alright in terms of the other changes that you've made, one of the significant ones which I noticed
was the underside of the bores have been essentially notched for want of a better term.
Can you explain what that's all about, why have you done that?
- Yeah so we'll offer a service on the finished block to machine ride clearance and we have
that modelled and done for 94 mm with aluminium rod so that allows us to basically
give out a prepped block to the customer where they don't have to do any additional machining,
cost savings, time savings, it's all done, we've already laid it out, played it out and machined
it for you.
- Just making the engine builder's job a little bit easier at the end of the day?
- Yep very much so.
- In terms of the accessories that bolt onto these engines, safe to assume that all of the external
bolt patterns etc are designed to take all of the factory bolt on parts, engine mounts, external
accessories etc?
- Yep so all the factory mounts are in the same location, water pump, oil pump, everything,
oil pan, anything that you would, factory, that you would pull the engine out and service
and change the block on, everything bolts right back up into it.
- In terms of power handling, obviously you haven't got this running out in the wild just now but given
the design parameters, what you've got in there, where would you sort of see the upper limits in
terms of power for this particular block?
- Yeah so basically we kind of set a threshold where we wanted when we went to the engineering
side of it, we're looking, you know the 2500 range and that's a great bridge between what you can
do with the factory block and then having the need to be in 3000+ horsepower billet block.
- In terms of options as well, for me this seems like it would be ideal for a street driven car or
maybe a road race application, particularly because it obviously still incorporates water
jackets and that's not to say billet blocks, billet alloy blocks also have the option to be
dry for drag racing or wet but I mean it seems to be a perfect solution, is that sort of where
you've designed this block to be used?
- Yep definitely and a lot of the drag race side of it, a lot of classes restrict, you have
to use an iron block so this just fits, right now the only current iron block available's
an OEM that you have to do a bunch of work to get it to the point where you can run high
horsepower levels where this will just be a good bridge and replacement for that.
- Can you give us any indication of where this is going to be in terms of price point when it
does hit the market?
- Yeah so we're looking, target retail is around $4500 and that puts you a little
bit over what you would have rolled into doing all these features on a factory block
but the availability and the strength added, I think that's a good point, the extra dollar spent.
- Is this also an aspect where Toyota may, or are running out of stock, I mean I know for
some of these older engines now, it can be increasingly difficult to source new blocks,
or is that still not an issue with a 2J?
- Yeah so I mean the 2J being such a global platform for so long, there's still a good amount
of cores out there but there's still a lot of not good cores.
And Toyota does still offer availability, sometimes they run those blocks but you have
to buy 'em as a factory short block and then you throw away half the components, rods, pistons.
- So a bunch of waste there in terms of parts you don't need.
- Wasted money, you're still going to have to put that added money back in the block so
by the time it's all said and done, you're probably over the cost of what this block would be.
- Now another term I wanted to dig into a little bit, you mentioned core shift.
Now we hear that term in reference to a cast block but what does it mean and how is the
Dart aftermarket block different in terms of core shift or what you can expect compared
to a factory OE block?
- Yeah so core shift is caused by the core, water core, sand cores they use when they cast, depending
on gasses and how the material's pooled in, they could float around and change position
slightly and that is what dictates on your finished wall thickness.
The way we cast blocks is quite different in aspects of how we pin and encapture our sand
cores to try to combat any movement during coring.
- OK so basically more consistency in terms of wall thickness, you're going to get exactly
what you expect every time compared to an OE block?
- Yep.
- Alright at what point does the alloy billet block make sense, is it now sort of 2500
horsepower and above, that's the only reason you'd go alloy or are there some other benefits
and downsides that you need to factor into your choice there as well?
- Yeah so you go to an aluminium billet block, there is benefits in the ability to be able to
repair it against a cast iron so if you throw a rod out the side of the block, cast iron,
there's no way to repair it, where a billet you can weld the piece in and remachine
it and move on and you also just have material strength.
A billet aluminium takes heat better, twisting and things like that and fracturing so depending
on the horsepower and the RPM and where you're at is kind of the threshold of when
do I need a billet block?
And 2500 to 3000 seems to be the next step where that's where you would want to step
up to.
- Yeah perfect.
Alright look it'll be great to see what those in the market, in the 2JZ market do once this
block actually hits showroom floors but great to learn a little bit more about it and thanks
for your time, if people want to find out more about Dart blocks and follow this one in particular,
how are they best to do so?
- Yep so you can visit us on our social media, Instagram, Facebook or our website at
dartheads.com
- Perfect, thanks for your time.
- Appreciate it, thank you.
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