ever wondered what smallport vs largeport looked like sectioned?

[ibizacupra]

ever wondered what smallport vs largeport looked like sectioned?

largeport above - smallport below

courtesy of http://forums.vwvortex.com/zerothread?id=3030975&page=2

 

[cordobabrendy]

Looking at the pics bill i take it the small port head can be ported out a fair bit, especially across the top half of the chambers? (it sees the majority of airflow, am i correct?) there seems to be an awful lot of metal so it could lose some without questioning reliability.

 

[ibizacupra]

it would take a fair amount of hogging out down the throat of the port... most restrictive part looks like just behind the valve seat on smallport.

 

[WeeJase]

ever wondered what smallport vs largeport looked like sectioned?

but i felt compelled to look

 

[Tallpaul]

That thread talks about AEB engines, is that the same head as my AGU?

Why did VAG change it anyway?

 

[ibizacupra]

That thread talks about AEB engines, is that the same head as my AGU?

Why did VAG change it anyway?

largeport

changed for improved low end torque.
predessor was ADR non turbo largeport which was slagged off for its poor torque. AGU came next using largeport head, but the turbo 5v motor was deemed to want a flatter more responsive non turbo type drive, hence smaller etc.
All well and good until you chase the higher power levels.

Come back big port. all is forgiven LOL

 

[RobT]

very interesting - but note they are not cut at the same place (channel for valve as evidence)

 

[WeeJase]

are the valves different thickness's ?
left hand side is thicker on the small port vice versa on the large.

 

[Songman]

The old agdage was - It`s not so much `smallport` or `large port` - rather the correct shape of port that really does the business! - and determining that, is a rather more complex task than it might first appear.

I stayed with the smallport for road use - the casting having been cleaned up and the ports opened out a little - preferring to sacrifice the few extra BHP at the top end offered by the large port head for the benefits of better part throttle running and fuel consumptin offered by the smallport

I don`t think there`s been a properly flowed and tested porting job on the 1.8T offered for sale to the consumer, on this side of the pond - of course, I stand to be corrected in saying that!

At the time when I was considering developing my car further, I approached CNC heads http://www.cncheads.co.uk/products.html - with a view to doing some pilot flow bench work for me - they looked promising!

 

[ibizacupra]

The old agdage was - It`s not so much `smallport` or `large port` - rather the correct shape of port that really does the business! - and determining that, is a rather more complex task than it might first appear.

I stayed with the smallport for road use - the casting having been cleaned up and the ports opened out a little - preferring to sacrifice the few extra BHP at the top end offered by the large port head for the benefits of better part throttle running and fuel consumptin offered by the smallport

I don`t think there`s been a properly flowed and tested porting job on the 1.8T offered for sale to the consumer, on this side of the pond - of course, I stand to be corrected in saying that!

At the time when I was considering developing my car further, I approached CNC heads http://www.cncheads.co.uk/products.html - with a view to doing some pilot flow bench work for me - they looked promising!

"...preferring to sacrifice the few extra BHP at the top end offered by the large port head for the benefits of better part throttle running and fuel consumptin offered by the smallport"


you think? Ported smallport on yours yes?
Spoke with CNC heads @ autosports. Need big wallet for their work, and the guy I spoke with did not convince me he was going to produce a head twice as good than anyone else, for double the cost he was talking about.

there have been flowbench results posted on vortex for smallport and largeport heads, with the expected flow difference you would imagine given the size differences.

All relative to the amount of air you are likely to pump tho from sizing of turbo etc. Vf34 not being a massive shifter of air, all things considered with its small exhaust housing.

The picture is in the US of A where bigger is better as normal, but in this instance the guys posting about it are all chasing 400+bhp power levels from large arse garretts. Each to their own.

 

[ibizacupra]

very interesting - but note they are not cut at the same place (channel for valve as evidence)

yea, agreed but when you side up a smallport head next to a largeport like I have its not just port but throat area to the valves and the bowles behind the valves which are larger on largeport.

Hogging out the port entry is only part of the change from small to largeport dimensions and all relative to what you are planning on pumping thru it turbo wise. k0x unit.... smallport is more than adequate. Pump more, and then other sizing comes to bare from t'body to intake mani, to ports, to exhaust mani, to exhaust housing to turbine to DP to exhaust.

 

[jj10]

@ Bill

What are the characteristics of the AYP engine...?

 

[ibizacupra]

@ Bill

What are the characteristics of the AYP engine...?

eh?
characteristics?

sorry, dont know what you are asking me

 

[h17och]

i thinkhe wants to know if the ayp is large or small port...going by what i just read..."k0x unit.... smallport is more than adequate" im guessing ayp is small port!? am i right in thinking that?

HoocH

 

[ibizacupra]

if thats the question then yea. all dbw are smallport hence AYP etc

AGU was largeport non dbw, ADR was non turbo largeport, AEB in the states

 

[tommo-turbo]

In that case are S3's smallport?

Rich

 

[jj10]

yep,

cheers hooch / bill