The Rwd 2Az-Fe Thread.

[philbey]

wowo I can't believe I just found this thread. Will have to go through in greater detail (only on pge 2 later) but this is an exciting build!

 

Just read up on this motor, good plan. It's in the scion's so I'm guessing the US aftermarket is strong, which means good, cheap bolt on parts!

 

Looking forward to this one.

[Sam_Q]

I would love to see the result of one of these engines with 48mm throttles, good extractors+exhaust, 270/270 cams and the hi-comp pistons with a good tune.

 

Sorry if I missed it what's the stock rev cut on these?

Edited October 7, 2011 by Sam_Q

[irokin]

http://www.briancrower.com/makes/toyota/2azfe_rods.shtml

 

Dayum! Look at the length of those rods!

 

Edit: Looks like its a stock photograph anyway, d'oh

 

 

Sam: I think 5600rpm and 6500rpm.

 

 

Edit 2:

 

http://www.scionlife.com/forums/showthread.php?t=202535

 

Wow, look at that crank! :|

[Sam_Q]

the more I look at this engine the more I am amazed, even near the main bearing supports they have a V support that's been hollowed out, the whole engine is like a dedicated race engine in how weight has been taken out of it everywhere.

 

So seeing how the crank looks solid could the rev limit be raised with new rods and pistons? I don't see why not

[Sam_Q]

doing some reading and a guy reports a change that works out to be a 28% increase in power from a cold air intake and a new exhaust head to tail-pipe. Working it out further that's 160kw or already equal to a beams engine

 

edit: also has no-one ever installed quad throttles?

Edited October 7, 2011 by Sam_Q

[irokin]

Personally I would prefer them to be filled in, not somewhere I think you should skimp on strength for weight. The crank is also sitting 'on' the block rather than 'in' the block like you see in SR, RB, 4A, 3S and probably countless others. I'm not saying that means there's be something inherently wrong with it, there's plenty of results that say otherwise already, just not convinced that performance was at all in their minds when designing it. I know there's a sump extension that bolts on the bottom but its not the same as having continuous metal.

 

I suspect NVH and economic manufacturing was higher on their list of design parameters than saving weight, especially with what is essentially a small second flywheel inside the engine. If you make a million engines and save $1 of alloy in each engine...

 

With the RPM, I don't envy those rod bolts job. Gonna be some serious pressures at higher RPM.

[Sam_Q]

actually the second strongest method of clamping a crank is level with the edge of the block like that, pending how much metal is on the other side, have a look at a deisel or an F20C, they have a split block design so the crank caps are virtually part of the second part of the block. The only thing more rigid is between two crankcases - ie: horizontally oppsosed engine like a flat 4. Now with that missing bit of metal that area with it's design already looks highly reinforced.

[irokin]

Yea? I would have thought a nice lip like this locating the crank girdle (or an even larger contact patch) would be preferred: http://www.sillbeer.com/blog/2009/10/

 

Even with those the SR has issues with the girdle walking necessitating larger diameter studs.

 

But the block skirt is below the crank centerline so its unlikely to mess up your CofG. Why not? Whats the harm if you're going to bolt on a slab of cast alumn anyway?

 

 

I quite like this design: (edit: essentially the same as an F20C ignoring the whole vee thing)

 

 

 

Irrelevant anyway, the 2AZ is what it is.

[Sam_Q]

here is the F20C with everything removed which looks fairly similar:

 

 

 

with the bottom half in place, like a split block

 

 

as used on diesels because of the massive load on them.

 

The SR20 though is just a 2 bolt main caps with some bracing bolted to the top, it isn't even one peice

[Sam_Q]

looks like the 2az doesn't use this, looking closer the crank is level but it just seems to have normal 2 bolt caps, which in this case would make much weaker than a burried set of caps, a waste.

Edited October 7, 2011 by Sam_Q

[irokin]

The SR20 though is just a 2 bolt main caps with some bracing bolted to the top, it isn't even one peice

 

Its a capable 1000hp engine, so how much is too much? No denying the F20C, that's an awesome design.

 

My thought process behind the skirt on the block was along the lines of, if you have a continuous structure below the the crank center line you provide extra resistance to the bending forces in the block above the crank center line. I can see how that force would be mitigated in the F20C design but less so in the 2AZ. Am I on the right track or am I imagining a force that isn't there?

 

The VH45 goes a step further than the SR design, the girdle contacts the skirt higher up and is cross bolted through it. Having trouble finding a good pic though: http://npora.ipbhost.com/index.php?showtopic=18663

[Sam_Q]

yes I see what you mean, my final thoughts is in this case your totaly right- it's weaker. If however they used what they already had and it a single structure then it would of been ideal.

[irokin]

I guess the one huge advantage the 2AZs design has is that if you ever wanted to make something like the F20C main cap, you could. Everything is provided on the engine block for you to achieve the same design. Just fire up the CNC and away you go. OK, maybe a little oversimplified, but it'd be a damn sight easier to achieve than on a block with a skirt ala SR20. I should add too that I don't mean to hold the SR20 up as a shining example of the greatest engineering ever, its simply the engine I have the most experience with and knowledge of.

[LittleRedSpirit]

Everyone always gets carried away with the hp potential.

 

Can I remind you fellas that its going in a sub 1000kg car. Its not a pissing contest, its a different thing, its all about minimal weight. Thats what the 2azfe is all about.

 

don't think of it in terms of HP per litre, think in terms of hp per kg of engine. That puts this engine squarely competing with 4age, 4k, 2tg, 18rc, et, and it smashes each and every one of them, even in choked up stock form.

 

Ive made up my mind, I am buying 11:1 JE pistons for it asap, as I want them some day and I know that the exchange rate is good now and wont be forever. When it hits 1.00:1.00 dollar again, Ill order a set. :laff:

[Sam_Q]

we know Matt we are just talking about theoretical design, it makes no practical difference to either of us at all.

 

So hows the manifold fab going?