20v Port Sizes Comparison Here

Just incase you've never had the misfortune of having a garage full of broken 20v engines and seeing the difference in inlet port sizes on 20vt heads.....

My camera battery died unfortunatly or I could have taken some better shots of the inlet tracts to the valves.

Spreadsheet Below from a previous thread with all the engine codes....

http://www.clubgti.com/forum/showthread.php?t=34368









Quite a difference i'm sure you will agree!

 

Above 1st pic - APX on Left (TT 225) AGU on Right (150bhp Golf Mk4)

More pics....(was struggling to get a decent pic without a tripod)

 

huge difference isn't there, measured it once,

 

is an agu head a direct fit on a 225 bottom end?

 

Why does the AGU have bigger ports? I would have assumed that the more powerful engine would have had bigger ports...

Oli.

 

More powerful engine has better cams and IVCT.
Has anyone visually commpared the exhaust ports both?
Port size, velocity, valve surface area and cam timing does affect engine pumping losses. I am sure the base engine team at VAG would have thought about this.

 

Yes

 

Good thread.

Any more head codes to jot down?

 

The 1.8T engine spreadsheet also gives info on port sizes in 20v engines!!

 

Those are engine codes, not head codes.
There only the two head types, big port and small port. As far as I am aware, they are all interchangeable, although I don't know if VVT can be swapped over or not.

 

Should have said head codes

Ah, dug it out:

http://www.clubgti.com/forum/showthread.php?t=34368

 

APX is small port????????

Holly sh@t! i sold one a while ago as a large port without checking (did think it was large mind) i will check this

 

APX is defo small port

 

I hope so, i'm re-building my large port AGU head and block for my leon (which is a small port AUQ with vvt) Looking at it the casting looks the same....but didn't look as close as i probably should have.

 

is an amk from an audi s3 big or small port?

 

repost

 

Small, all K04 equipped engines are, see spreadsheet above

 

stupid s3 engine. lol i want big port

 

only worth going largeport if you have a turbo to make use of the extra airlfow potential, otherwise you will loose some low to midrange torque. even the case on ported smallport.

 

isit worth going big port as the car is mapped to 270?