Need help with 911 Heat Exchanger Questions

[sundlh]

I am the original owner of a 1979 911SC with 75K miles on it. The original HE's have some rust so I bought a used pair in great condition but have not yet pulled the originals off the car. Ordered all new gaskets and hardware from the host, tried to fit the new manifold gasket to the replacement HE and found that the stainless gasket for my year doesn't fit: ......just a wee bit to small on the hole ID to fit over the tube that goes into the head.
Here is my concern......if my replacement HE's are from a 1983 or later 911 are the ports in the head a larger size than on my my 1979 911SC?

When I bought the new/used HE's I was told they came off a 1978 SC.

Given that the new gaskets are a wee bit too small I am now concerned that the exchanger won't mount onto my engine do to larger tubes at the flange site.

Any help or insight is welcome before I begin to dismantle my heat exchangers.

FYI the numbers on the new/used HE's is 93021102901 and the number above that is 911/122

Many thanks for any help!
sundlh

[steve911T]

sundlh, Bad news, google search for the pn above.
93021102901 - PORSCHE DANSK TURBO HEAT EXCHANGERS, 930/911 1984-89 ...
Click here to buy the Porsche 93021102901 - DANSK TURBO HEAT EXCHANGERS, 930/911 1984-89, PAINTED STEEL. Seems whomever sold this to you did not know what they had or did not bother to tell you the truth. Good Luck. Steve

[TibetanT]

sundlh

Welcome to the Pelican forums!

Unfortunately, the early 3.0L engine MY 1978/1979 have a different flange then the late style heat exchangers (MY 1981-1983). The heads exhaust ports are different sizes on the 78/79 versus 1983 heads exhaust ports. Thin flange versus thick flange is the issue I believe.

I hope you can get some resolution with this issue via the seller.

[sundlh]

Thanks for the quick answers...........looks like I have a great set of 1983 to 1989 heat exchangers to sell!

sundlh

[snbush67]

Your 79 heads have 35mm exhaust ports. The later SC's have 35 mm exhaust ports as well exept they have a 39mm step to accept the gasket blow out sleeve so the ID of the sleeve will still be 35mm. This means that you can cut of the sleeves from the later heater exchangers, and change the headstuds to the later, longer ones if you want to use those later thick flange exchangers.

Most people break a few headstuds while removing the old exchangers. Be prepared for this as it will require some skill in extracting broken studs. Also have your new studs, barrell nuts and copper nuts ready to go.

Shane