goran, do you think thsat it is worth having the heads ported while they are being twin plugged? will it release much hp?

Well I do believe it's worth doing some port-matching and boring out intake paths. But I'm not sure that it's worth doing the whole enchilada with flow-bank, MIRA-cutting valve seats, doing extensive grinding etc.

Just port-match them to Carrera intake and be done with it. there is a K-Jet injector notch inside 930 head intake port that is somewhat hard to match to Carrera intake but it can be done quite well. Or even better, sell 930 heads to someone who believes in stories about superiority of alloy used to manufacture them and buy yourself a set of decent Carrera heads ;)

http://forums.pelicanparts.com/uploa...1092579612.jpg

You can see the notch in 930 intake port that is there for K-Jet injectors? It doesn't really fit with notch on Carrera plenum flange but it can be made somewhat bigger.

Hey beep thats my engine!... Just drove it to work today for the first time in a year!

More info on what must be done:
http://forums.pelicanparts.com/uploa...1100540126.jpg

#1: 930 head with green outline on what has to be removed to match Carrera intake.

#2: 930 head ported to match Carrera inline, notch still not widened.

#4: Carrera gasket

As you can see, Carrera heads have flanges that are a bit wider and OEM gaskets won't seal perfectly. You have to either leave the notch as it is and just port the circular part to right dimension, or add some material (epoxy or such) to be able to seal perfectly with OEM seals.

Hehe...sorry for borrowing your pic w/o asking! :) Just searched for a pic of 930 head ;-)

I am with ya...I plan on using the "duck" also......just have not determined where to start cutting.........I want a sleeper turbo not just a whale tail....in fact just my "duck'!

so goran, do you think that the carrera heads are a good move for my build? has anyone else used them in a 930 turbo?

P.S. thanks for all this info!

Another way to look at this is .... we have used 3.2 heads in turbo motors...they work well

Well I'm certain you won't have any problems with them compared to 930 heads. Juan Ruiz is using same heads and is pushing 600+ HP...
Only problem I can recognize is that 3.2L Carreras have 95mm cylinder bore compared to 97mm on 3.3L 930.
I don't know if headstud holes align on 3.3 engine considering it has 2mm bigger jugs (there is probably somebody at this forum who can answer that question).
When it comes to port sizes, OEM 930 head has 32mm intake and 34mm exhaust ports. Coresponding values for Carrera heads are 40 and 38mm, respectivly.

Cheers!

I have read somewhere that they (3.2 heads) are not the same alloy as the 930 heads; i.e. not designed to withstand as much pressure or head.
Maybe its something that you want to research a little more first.

The 3.2 and 3.3 use the same case and the same head stud spacing.
-Chris

Funny, from that picture set, it looks like you're doing the work on the heads with the engine still assembled!

-Wayne

Wayne, do you have a view on using carerra heads on a 930?

Andy

Yes, It has been discussed an nauseam and most of people (including me) agreed that it's of minor importance.

I would certainly use Carrera heads on 930 engine, as they flow better w/o need of porting and are perfect match for Carrera intake.