Weber Manifold Question

[sprbxr]

I bought an early 911 with a 2.7 engine with Webers. It looks like the manifold mating surface is not compatible with the heads. The heads have an area within the port where the old injector would have been. The manifold that is on the car is smaller than the existing area where the injecotr would be in the port. I think I might have an early 911 pre-injection manifold. Is there a manifold available that will work with these heads?

[jpnovak]

All but a few 2.7 engines would have come with CIS (K-jetronic) injection. There are openings in the heads at the intake for the injectors. To make the manifold mate correctly you will need to do two things.

First separate the carbs from the manifolds and lay them on the intake. Use a carbide cutter on a drill to port them to match the diameter of the heads. This is usually a few mm.

Next Call PMO carbs and get the CIS spacers and gaskets for the manifolds. They make a special shaped spacer that will cover up the injector indentation. They should not be too expensive.

These are both easy fixes. Welcome to the board and enjoy driving the car.

[Evans, Marv]

I think you are talking about the "notch" in the head where the injector goes. If I remember correctly, you just let either Pelican or PMO know you are mating the injection heads with a carburetor manifold when you order gaskets. I don't think it's a big deal. They will send you the gaskets you need to take care of it. If your manifold ID is smaller than your intake ports, you may need to get manifolds to match or machine out the ones you have.

[john walker's workshop]

the phenolic spacer fixes the problem, and you need it anyway to help keep the engine heat out of the carbs, so they don't perk. PMO also sells the drill jig to vent the carb tops, which also keeps them from drooling due to vapor pressure in the float bowls.