Ssi compatibility question

[mclmk8d]

Can a thick-flanged SSI that was originally on a 3.0 engine fit a 3.2?

[snbush67]

The bolt spacing is the same. The thick flange were originally meant for the longer 3.2 studs, which you should have.

Were the inserts cut off the SSI's? If so then they will still fit but you will have to use the 3.0 gaskets, which are cheaper, but you lose the blow-out protection form the insert and the metal 3.2 gasket.

Without the insert the step down form the 3.2 exhaust port may create a little turbulance in air flow, I dont think you will notice.

[cdrik915]

Normally yes.

You'll just need washers ( or a custom piece of metal) to compensate the flange height.

[arbita1]

The 3.0 exhaust ports are smaller thqn the 3.2 though. Is it advisible to use them?

[snbush67]

Originally Posted by arbita1

The 3.0 exhaust ports are smaller thqn the 3.2 though. Is it advisible to use them?

Once the exhaust sleeves are inserted into the 3.2 ports it results in an ID of 38mm which is the same as the 3.0.

For each system, at the point where the exhaust meets the ports are both 38mm which matches the ID of the SSI's.

When using SSI's with the sleeves (inserts) removed, a step would remain open which could cause a little turbulence

[arbita1]

Shane, I have to respectfully disagree with you there. I think you are mixing up the two different types of SC engines.

The 78-79 has thin flanges and no colars.
The 80-83 has thick flanges with collars, but the diameter of both.are the same.
The 3.2 has thick flanges and larger collars due to the larger diameter exhaust ports. A 3.2 SSI does not fit on a late SC engine unless you cut off the collars.

[mclmk8d]

Originally Posted by arbita1

Shane, I have to respectfully disagree with you there. I think you are mixing up the two different types of SC engines.

The 78-79 has thin flanges and no colars.
The 80-83 has thick flanges with collars, but the diameter of both.are the same.
The 3.2 has thick flanges and larger collars due to the larger diameter exhaust ports. A 3.2 SSI does not fit on a late SC engine unless you cut off the collars.

But will the opposite work: A 3.0 SSI on a 3.2 engine?

[arbita1]

Technically it will fit. But i would be worried about choking down the exhaust at the flange.

Why do you want to use Ssi's on a 3.2?

[E Sully]

I used the thin flange SSI's from my 1973 on my 3.2 conversion and it ran great. If I was going to track the car I might consider something else, but on the street it pulled very well with a bursch muffler.
1973 Porsche 911T 3.2 Engine.wmv - YouTube

[Josh D]

Originally Posted by E Sully

I used the thin flange SSI's from my 1973 on my 3.2 conversion and it ran great. If I was going to track the car I might consider something else, but on the street it pulled very well with a bursch muffler.
1973 Porsche 911T 3.2 Engine.wmv - YouTube

I've watched this video several times from being posted in other threads and I always think of what a sleeper that car must be! Keeping it low key in looks, but with a nice powerplant. Nice job!

[porschenut]

The 3.2 needs 1.625" primaries, but SSIs are 1.5", which is really too small. This was discussed at length in this thread -

Best exhaust with heat for a 3.2?

[snbush67]

Originally Posted by arbita1

Shane, I have to respectfully disagree with you there. I think you are mixing up the two different types of SC engines.

The 78-79 has thin flanges and no colars.
The 80-83 has thick flanges with collars, but the diameter of both.are the same.
The 3.2 has thick flanges and larger collars due to the larger diameter exhaust ports. A 3.2 SSI does not fit on a late SC engine unless you cut off the collars.

Matt,

I agree with everything you have said here. I think I read into the OP question.