half of a 4.2l 40v head....????

[1999.5GTIVR6]

Hey just pulled this from the hybrid swap forum, wondering if anyones heard of this. Iv tried googling with no luck
Sorry I'm on my blackberry and can't copy the link at the same time but here's what the poster said.

"ive recently heard of folks using the passenger head from a non fsi 4.2 v8 on a 4cyl bottom end for the larger ports and cams along with the infinite ablity for adjustment of the t-belt sprocket on the cam. i currently have one at my fingertips thats still bolted on a v8. ive counted the teeth on the cam gear and its double my crank pulley. also the intake and exhaust bolt patterns and angles look to perfectly match a regular 20v head. also the valve cover is shorter and flatter that any regualar 20v. just wondering if anyone on here has physically done this and any small things i need to know before i do this...also curious as to what compression ratio is on a 2.0 bottom end... "

[Big_Tom]

never heard of this... sounds interesting tho

[screwball]

I thought it didn't work w/out machine work or something. It's definitely been looked at but it can't be that viable of an option if the big dogs are still running what were AEB cores before they were ported.

[theswoleguy]

I thought it didn't work w/out machine work or something. It's definitely been looked at but it can't be that viable of an option if the big dogs are still running what were AEB cores before they were ported.

indeed but let christopher columbus pioneer the way! i like new things.

[speeding-g6O]

bore spacing is off.

the 4cyl has a center to center measurement of 88mm. the V6 - V8 - V10 Audi motors have a bore spacing of 90mm.

but it would be wild to do, have a rocker arm valve-train and HUGE ports!!!

[DMVDUB]

Custom blocks from IE for 4.2l head FTW!

[groggory]

Custom blocks from IE for 4.2l head FTW!

That would be wild. Billet block and 4.2L head.

Massive power potential plus huge weight savings.

The number of people who'd pony up the big money for a billet block would be few and far between. I don't think the development and testing time for this would be worth it for most companies.

For example, you can see here a Billet 4G63. It's selling for $8,000.
http://www.bulletcylinderheads.com.a...subishi%204G63

I don't know how many people would be willing to spend that kind of money on a billet 4.2L compatible block.

But god, that would be awesome. Billet block, super high flowing head, all connections optimal right from the block with ANORB ports, built in compatibility with a dry sump system, Moly cylinder sleeves, integrated crank girdle, and cool performance bits like that.

I bet that the typical long block price for that sorta engine build would easily be $30k.

[jettred3]

http://www.google.com/imgres?hl=en&s...s%3A0%2Ci%3A84

[jettred3]

someone made it work.

[jettred3]

IIRC, only a 3.6L head can work (4.2 cyl. offset poses a challenge) and even then, the block needs to be bored out. This type of combo is the best for a 16v...if you got the money. You'll need a min. of a 2.1L for these heads to work.

They both use the same cast. The valve placement is different on the V8 head (due to the 84.5mm pistons), the coolant holes would need to be welded also but the base cast is identical to our 16v heads.

I was looking into this awhile back but there are no real benefits to using the head other then the wow factor.

I think Breadfan was building one.

The Big boys overseas don't **** with that ****. It's an Audi STW head most likely. The Head is canted to aid the 90degree exhaust valve angle and has different port work like huge ovaled exhaust ports.

[1999.5GTIVR6]

Sorry I'm still learning,
When you say the centre to centre measurement is that to the centre of the piston, and the center of the cup the 5 valves sit around?

This is just curioustity I don't have intentions of building of these heads. But what it you where to usde a different 06a block? Like on a bored out azg or alh

[DMVDUB]

It would just be nice to be able to flow as much as a 4G63, SR20DET, or WRX....

our best AEB head gets us what? around 250ish (I)

when a 4g63T sees over 270cfm (I) stock and 290-300+(I) ported

a Nissan SR20DET is in the 260-270cfm(I) range (depending on spec, lowest is ~205cfm)

then the WRX EJ25 pulling out at 300cfm(I) stock and close to 350cfm(I) ported

All of the competitors are larger displacement, yes. But we can bore and stroke ours out to 2.1l-2.2l which is bigger than an SR20 and in the neighborhood of the 4G.

It's just so much easier to pull high numbers out of those engines it's ridiculous. My old Talon / Eclipse took ~ $3.5K to make a reliable, 400+awhp car (t3/t4`50), given it was spray'ed as well it was still only running 18psi for those numbers. With another $1K I could've been in the 500-600+awhp levels without NO2.

RIP Frankenclipse

[speeding-g6O]

yes from center to center on the pistons.

and the AEG, AZG, ALH, they are all 4cyl and are ALL 88mm bore spacing.

[screwball]

I mean if we're dreaming here why aren't we 2.X+ liters from the door??

[speeding-g6O]

yeah its the 32v 3.6L.... not the 40v 4.2L

here is the information out there on the subject, or some of it.

the cool thing if it were able to be done with the 40v 4.2L is the rocker arm drivetrain.

http://forums.fourtitude.com/showthr...-on-1.8-16v-KR

[Rac_337]

Custom blocks from IE for 4.2l head FTW!

IE should just make custom head casts to get the numbers we all would like to see

[DMVDUB]

They are making heads aren't they.. but I don't think they've released the CFM.

I'd like to move on to another 1.8t project in a Quattro form so I can effectively run a BT 1.8t and it would be nice to be able to build an engine from the block to the head that is in line with the competition. Starting with a 2.0L-2.1L stroker, and a custom high flow head would be a great start to a project.

[1999.5GTIVR6]

Well talking about cfm and flow, doesn't that increase with manifolds, cams and larger valves? What kind of cfm gains could we achieve with products suchs as ie race cams.

Or did I miss something...

[DMVDUB]

Yes all of that increases flow. But the flow still has to go through the head, and if the head isn't big enough it too will become a restriction.
You could infinitely make power as long as you have enough air to mix with the fuel, you're only limited by the amount the engine can pump in and out. So having the flow to do that makes a world of difference.

[Big_Tom]

Yes all of that increases flow. But the flow still has to go through the head, and if the head isn't big enough it too will become a restriction.
You could infinitely make power as long as you have enough air to mix with the fuel, you're only limited by the amount the engine can pump in and out. So having the flow to do that makes a world of difference.

^^^ yep. I'm pretty sure all the popular Honda, Nissan, DSM heads all out flow ours when comparing stock to stock. Some of them by a pretty size-able amount

[1999.5GTIVR6]

Hmmm, yes iv heard that a lot of jdm motors out flow ours, but isn't that stock comparison what kind of flow can we look at from an aeb head vs an awp head? I understand that the aeb has larger ports therefore easier air flow, but how is it affected with an awp head, what affects does the extra velocity have?
How do our heads react when we certain things.
Something I noticed with hondas are a lot of flow but low tq. Anyone know if there is a connection?

Shouldn't our head be flowing ridiculous amounts like we have 5v per cylinder. Given they are weee little ones ?

[DMVDUB]

Our low end torque is really just gained by a small framed turbo. Remove the turbo and you have neither tq or hp.

[DMVDUB]

Remember too, most Honda's are 1.6-1.8L and at those levels naturally aspirated they destroy us is numbers every time. Remove our turbo and go 1.8 to 1.8 and see what happens. We end up with around 120hp (if lucky) , when they are putting down 100 hp per liter. As for tq they would probably win too.

[1999.5GTIVR6]

Hmm yeah this is very true, I completely overlooked the turbo

Well what can we do to increase the flow of our heads, obviously oversized valves and tons of goodies.
But if we were to re design the head inorder to allow use to flow what the competition is flowing.
I need to learn a bit more of how our head flow.
In my mind I think we are being limited due to velocity,and turbulances build up on our intake but if I'm
not mistaken we are more limited to our exhaust flow then intake flow correct? Adjust duration and lift and you will see more flow or less. Is there a formula to calculate this with 1mm larger valves ? How much additional flow could be expected? Or are they a suffiecnt size, and the abgle they are on limit them?

I understand that in order to achieve better flow results when porting and plishing you should spend a lot of time on the valve job and throat areas (this is where we nice gains)

Wouldn't you see larger flow numbers on tubular manifolds over logg? Or do they not affect flow overall throughout the head (both are large enough to not inhibit the flow)

[DMVDUB]

The velocity is good in the VW/Audi head. The CFM isn't that great.

[GolfCL Smooth]

Hmm yeah this is very true, I completely overlooked the turbo

Well what can we do to increase the flow of our heads, obviously oversized valves and tons of goodies.
But if we were to re design the head inorder to allow use to flow what the competition is flowing.
I need to learn a bit more of how our head flow.
In my mind I think we are being limited due to velocity,and turbulances build up on our intake but if I'm
not mistaken we are more limited to our exhaust flow then intake flow correct? Adjust duration and lift and you will see more flow or less. Is there a formula to calculate this with 1mm larger valves ? How much additional flow could be expected? Or are they a suffiecnt size, and the abgle they are on limit them?

I understand that in order to achieve better flow results when porting and plishing you should spend a lot of time on the valve job and throat areas (this is where we nice gains)

Wouldn't you see larger flow numbers on tubular manifolds over logg? Or do they not affect flow overall throughout the head (both are large enough to not inhibit the flow)

One step at a time my friend... you're spiralling out of control here.
For a basic lesson in fluid dynamics you can get some good information on google, which will include many archived threads from this forum.

[1999.5GTIVR6]

So your saying the cfm and velocity isn't related ? If we improve the turbulence inside the head it wouldn't flow more? Or simply saying the velocity characteristics isn't what limits our cfm.

What's the stock velocity of these heads? Aeb vs awp? fps.
What exactly controls the air speed though. From the top of my head you would have different variables for every motor right? Like you need your head to flow the necessary flow to support a the engines displacement (which changes with strokers) and rpm band. If your ports are to large to flow a good inertia wouldn't we see a drop in voliumetric efficiency? So for larger motors and high rpm motors larger ports be ideal but small ports are better for power below 5000pm and smaller motors.

So if someone were to port and polish their head adding some sort of velocity stacks and and knife edging exhaust on the exhaust side. Make for less resistance for the flowing air, and in turn it moving faster through the head

[GolfCL Smooth]

So you're question is... will machining work and upgraded components yield increased power output? Or is this all rhetorical? I think you need to do some reading before asking fundamental questions regarding cylinder head flow, or this thread will get out of hand.

CFM and velocity are obviously related. Q = V x A
You can port the head to increase area, improve manifold characteristics and runner size to increase velocity and area. If your area is too big for the displacement of the motor you decrease velocity. Etc. Etc.

The variables are all the same no matter what make or model

[1999.5GTIVR6]

Yeah, I obviously have a lot more reading and learning to do.
The questions I was asking were all theory based,

I'm just have trouble finding good resources to start learning from, I have some general concepts but need a good foundation to build on. Not asking to be spoon fed information, but does anyone know a good place to start learning and reading it seems ill read hours into stuff but then get hung up on basics again. .

[groggory]

Yeah, I obviously have a lot more reading and learning to do.
The questions I was asking were all theory based,

I'm just have trouble finding good resources to start learning from, I have some general concepts but need a good foundation to build on. Not asking to be spoon fed information, but does anyone know a good place to start learning and reading it seems ill read hours into stuff but then get hung up on basics again. .

http://www.amazon.com/Modern-Engine-.../dp/0854299785

[Issam Abed]

is this 2004?
Seriously the 4.2 heads are a complete PITA to make work.
Even if you wanted to take full advantage of the rocker arm set up , you will still need custom cams (don't try and run the V8 stock cams unless you want to bend all your valvetrain using it on a 4 cylinder) as well as custom valvetrain as the S8 internals are slightly different to off the shelf 06A 1.8T components.