Pre 74 Style Exhurst On 3.2 Engine

[1972_911T]

If I want to keep my authentic 1972 exhurst sytem on my transplanted 3.2 engine do I need a special exhurst to fit the 3.2 or will any pre 74 exhurst and HE's fit my 3.2? My engine is a euro version with no oxygen sensor.

Steve

[DW SD]

Though yours is a Euro motor, I think yours should have an O2 sensor. I think you can use the early HEs, but you may have to install shortened exhaust studs OR use a washer stack to take up the difference in flange thickness at the exhaust port.

You may want to run an O2 sensor and install an O2 bung into the HEs.

Doug

[skinnerd]

They make a set of SSI's just for 3.2's (different exhaust flanges than say 2.7 or smaller motor). I had a threaded collar welded into the left SSI into which my O2 sensor is installed. Any 73 and earlier stock exhaust will bolt right up.

[1972_911T]

Mine definatly doesnt have an O2 sensor alot of the euro's dont it has a bung screwed into the dansk cat replacement pipe where the o2 sensor should be and the connector for the o2 sensor has a weird plug in it that I presume must overide the system. I posted about this in the past when I first noticed it didnt have one as I was under the impression the motronics wouldnt work without it and a few other euro engine owners confirmed theres was the same.

[1972_911T]

Will the early HE's have less gas flow than the backdated ssi's that are intended for the 3.2?

Thanks Steve

[jinos]

Got a clean pair of early HE's if you're interested. Here's a pic.

[deoxford]

Steve,
I am looking in to the same swap very soon, and my research show that the stock HE from the 72 will be like headers. All you need to do is change the studs.
Derek

[Jeff Alton]

Changing studs is not a simple task. I would be more inclined to trimming them or using washers between the nut and the flange....

Cheers

[SteveM911]

I fitted early 72-73 style heat exchangers to my modified 3.4 engined Carrera, used washers rather than shortening or removing the studs, a bit of a fiddle, but doable, I had rusty old headers on but needed heat for the winter in the UK,
Did not notice any difference in performance although I probably lost 2-3 hp.

[Joeaksa]

Originally posted by 1972_911T
Will the early HE's have less gas flow than the backdated ssi's that are intended for the 3.2?

Thanks Steve

Do not believe that there are any major differences between the early HE's and the SSI design. SSI may have changed the flanges in several models, and added the O2 sensor bung but believe that the tubing size is the same. May be wrong.

The major difference is that when you buy the SSI's, they are the last set of HE's you will EVERY buy for the car! They are stainless and will not rust out like the factory HE's do every few years, with the loss of heat and defrost up front. Plus they just look nice and preform!

Joe A