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billjam billjam is offline
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Join Date: Aug 2007
Location: Perth, Western Australia
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Originally Posted by JBL930 View Post
Turbo heads are made from RR350 alloy (it'll be printed underneath the head somewhere), ...
Correct ...

Mike, I have also been looking at heads lately and after some input on other threads by Rarly and others, it seems that going with larger ports is NOT the way to go on our charged engines. The clear consensus is that maintaining air velocity through the inlet ports is important for retaining low end power.
Driveability is important to me so I don't want to throw away low end power just to get more power at the top end (can always get more boost!).
I haven't figured out to link to it, but I suggest you look at some of the posts on my recent thread related to "stupid inlet spacers" as there might be some useful info there for you.

Consequently, I have decided to stick with standard inlet spacers (32mm ID) and inlet port size. What I have done though is smooth out the various bumps in the ports and open them up a little under the valves to ease airflow in and out of the head. See the befores and afters below.
Still to be done is some polishing of the exhaust ports and the combustion chambers, but that is next weekend's task.

Old 07-25-2008, 05:15 AM
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