Help Identifying These Heat Exchangers

[Jeffreypang911]

Had them sandblasted. So my car is a 1974, but has a 1987 3.2 Carrera swap. These are clearly from an older vehicle, but just don't know when. They fit on the motor, but they seem like they would be from a 3.0 motor or smaller. 1.5 inch OD, No cross over pipe.

Anyone know by the photos above? I purchased another set of headers (not shown) for an earlier 2.7-3.0 porsche thinking they would fit but sadly they dont - I made the assumption that if these headers fit my newer motor all headers are interchangable.

Thanks.

[75 911s]

They could be the original stock heat exchangers from your 74. Later, the company SSI incorporated this design and many people (like me) use them on motors 2.4-3.2. They are preferred due to the even length headers and superior heat boxes. They are perfectly acceptable for the 3.2 and can provide a bit more torque than a larger diameter exhaust. Jet coat them and put them back on is my advice. That little tube at the top of the heat exchanger is for the MFI that you don’t have so you can cap it off when you reinstall them.

[Jeffreypang911]

Originally Posted by 75 911s

They could be the original stock heat exchangers from your 74. Later, the company SSI incorporated this design and many people (like me) use them on motors 2.4-3.2. They are preferred due to the even length headers and superior heat boxes. They are perfectly acceptable for the 3.2 and can provide a bit more torque than a larger diameter exhaust. Jet coat them and put them back on is my advice. That little tube at the top of the heat exchanger is for the MFI that you don’t have so you can cap it off when you reinstall them.

Thank you, Will do.

What function did the little port do for the MFI system?

[75 911s]

The snout is for a hot air hose that connects to the left SSI through the engine tin and it warms up the thermostat to adjust mixture on a mechanical fuel injection setup.

[RarlyL8]

2.2L-2.4L MFI. Not optimal for use with larger 3.2L engines. 1-5/8" primaries are a better choice.