1.6 is 34mm in 31mm ex
1.9 is 36mm in 31mm ex
Tdi is same as aaz but slightly different lengths
I robbed this from a post. Don't know if it is 100% accurate, but I wanted to be able to find this next time around. I think this is the main reason the aaz head is the upgrade to the 1.6...time will tell.
port shape is also much better on the AAZ.
And later AAZ and all tdi have 7mm stems as opposed to 8mm.
port shape is also much better on the AAZ.
So I hear people say, but I really think the oval will flow better than the D. The D might have less turbulance or less tumble, but until my next project I won't know for sure.
port shape is also much better on the AAZ.
So I hear people say, but I really think the oval will flow better than the D. The D might have less turbulance or less tumble, but until my next project I won't know for sure.
i would think the D port would flow better, because its bigger..
bigger ports usually flow better..
port shape is also much better on the AAZ.
So I hear people say, but I really think the oval will flow better than the D. The D might have less turbulance or less tumble, but until my next project I won't know for sure.
i would think the D port would flow better, because its bigger..
bigger ports usually flow better..
Agreed somewhat. The my 1.6 head intake port measures 1-3/8 tall x 1-1/8 wide oval. My AAZ head intake port measures 1-7/16 tall x 1-1/16 wide. I really think the valve is the big difference in flow. The shape is probably to reduce tumble/turbulation, which should help performance. I want to do both a 1.6 and 1.9 head and see what actually does better at a HG change....horribly off the topic here, sorry. If I go further I will split the thread.
1.6 is 34mm in 31mm ex
1.9 is 36mm in 31mm ex
Tdi is same as aaz but slightly different lengths
I robbed this from a post. Don't know if it is 100% accurate, but I wanted to be able to find this next time around. I think this is the main reason the aaz head is the upgrade to the 1.6...time will tell.
I can vouch for the 1.9 and 1.6 Exhaust valves being the same diameter, I ordered them that way for my AAZ head.
The Intake valves are different, AAZ larger, 1.6 smaller.