'80 RoW 930/09 2R or 4R intakes?
 

I'm preparing my list of seals and gaskets for an upcoming engine drop sometime this winter to reseal, clean, and detail the engine. I would like do replace the vacuum lines and intake tube sleeves as well.
However, I have not been able to definetively determine if my '80 RoW 930/09 has the smaller 2R intakes tubes or the larger 4R tubes to ensure I order the correct intake sleeves. I've read countless threads and I also have Waynes and Bruce's books, but continue to run into contradictions.
I've looked at the tubes themselves, even with mirror, and can't see an entire part number.
Does anyone definetively know which intake tubes are on the 930/09?

Thanks in advance.

My engine type summary shows the following:

The 1980 ROW engines are designated 930/09 and have the lower 9.3 CR and smaller intake runners/ports

The 1981-83 ROW engines are designated 930/10 and have the 9.8 CR and the larger intake runners/ports.

May I ask where your information is coming from? Everything I have shows the 930/09 as having 8.6:1 comp ratio. Also, both Wayne's and Bruce Anderson's books show both 930/09 and 930/10 as having small ports. But I've read threads on here that say what you did about the 930/10 having the bigger ports.

The 930/09 was basically a 1980 USA engine without the lamda system or catalytic converter. It did use the smog pump with air injectors.

Do a Google search on "Porsche engine 930/09"

You can also confirm the ports size by checking the OD of the intake runners with a dial caliper

The large port are around 48 mm diameter and the small ports are around 40 mm.

Thanks. I'll check the OD before ordering the sleeves.

Measured the OD of the intakes when I got home yesterday and the calipers registered 1.88" (47.7 mm), so it looks like I do have the larger intake runners. I would suspect then that I also have 39mm big port heads! Cool!

Can anyone say with certainty that Porsche used 4R intakes with 34mm port heads? I really can't see them doing that. I guess I'll know for sure when I drop the motor and pull off the CIS.

Your engine should be the same as 78-79 USA SC.
So you should have big intake runners.
Big port heads.
8.5/1 comp pistons--I know for the 80 Euro they are listed as 8.6/1 but they use the same p/c as the 78-79 USA SC.

Yep, this is what I figured but needed to confirm. Thanks!

Yep, my 81 SC ROW 930/10 has 9.8cr and the 4r CIS runners with the big valve heads found on the 78/79 SCs, Mahle/Nickie P&Cs etc

Basically the 930/10 is a 78/79 SC 3.0 with 9.8.1 cr, single line to the dizzy pot and no air injection like the 78/78 SCs had, there is a lambda system now that it was federalized