removing just 1 CIS runner to check port size

[phelix]

My 3.0SC engine (in a 914) has a designation of 930.07 which suggests it came from a 1980 SC. In theory it should have small port (34mm) heads. Because of space constraints in the engine compartment the CIS from a 2.7 was used. I have no details but allegedly the cams and pistons were changed and it was suggested the output was around 240 bhp. I'm taking that with a pinch or two of salt...

As part of an autumn/winter project I'm considering replacing the CIS with ITBs. The ITB supplier wants to know the intake port size. The part numbers on the intake runners correspond to those from an early 2.7 engine (for example, 911 110 168 0R). I assume the port sizes are standard but don't know for certain.

In order to confirm the port size is it possible to remove just one intake runner without pulling the entire CIS system? Any advice would be appreciated.

[Tyson Schmidt]

Yes, definitely possible, and pretty easy in fact.

Except that it’s in a 914, which makes easy jobs difficult.

Just unscrew both clamps on the rubber sleeve and slide the sleeve over the runner. Remove the two nuts at the port and out it comes.

[boyt911sc]

Phelix,

Just read the part # on the intake runners. The last 2 digits will identify the ID of the intake runners. The -2R means 34-mm ID and -4R means 38-mm. Now, to verify and confirm the actual port size of the cylinder heads, there is no substitute for visual inspection.

Tony