Combustion chamber difference VW/Audi 5V 1.8T 2.7T

[lion_rapid]

Could anyone shed some light on this?
Why R4 (and V8) 5V Audi engines have squish/quench areas, while V6 engines not? (Regardless they are boosted or not).

[gunt]

i'm barely familuare with them , do years stand out or are they available in the saem year , also does the 1.8 vary in style per bhp , codes [ bam ] ect

[mag2555]

What do the piston tops look like?

What are the bore and stroke specs of the 3 motors?

[lion_rapid]

Both pistons are 81mm diam.
Stroke 86,4mm on both engines.
1.8T 9,5:1 180HP
2.7BiT 9,3:1 265HP

[BLSTIC]

What about the inlet ports? There may be differences in the tumble generated that would explain the difference in squish pads. Were they designed at the same time?

[mag2555]

Besides the above possibilitie it could also be due to one combo having a faster piston speed when approaching TDC, as in quicker cylinder pressure rise.

[juuhanaa]

Do you know whether the roof of the port is inline with the deck, or if the runner has an offset to cylinder head? I had a trouble making all that, but i still wouldn't recommend it without a flow bench.. I also have wrong seat angles and open chamber, but i honestly didnt know what i was doing

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-juhana

[lion_rapid]

Besides the above possibilitie it could also be due to one combo having a faster piston speed when approaching TDC, as in quicker cylinder pressure rise.

Both engines have the same stroke and redline. Similar amount of boost.

[Bigchief632]

Could it be as simple as the one is bigger and more open, and the one is tighter and smaller, simply to hit the target compression by the manufacturer? It really could be that simple.

[lion_rapid]

Both engines have the same intake ports in the cylinder head.

[gunt]

or as per all then real odd stuff , some were intended for racing and had features built in so they were included and the rest suffered a bit but would have to live in the real world with varying fuels / countries