Installing SSI heat exchangers on 3.2 - what to expect

[Discseven]

Stainless and craftsmanship of these SSIs borders fine art. Were they plug & play on a 3.2, even better. They’re not. Being a “back date,” some fitment oddities should be expected—this post covers the oddities as I encounter them. SSI here is part # 91.917SSI. Dansk muffler fitted is 2-in-1-out, part # 1620607900. Engine is ‘85 3.2. (Parcel to this SSI + Dansk engine mod is replacing stock cams with 964 cams ground by Webcam.)

EDIT: I initially fitted the muffler (photo above) to check the alignment of bolt holes between it and the SSI exhaust pipes and they're right on BUT... once the saddle is on the engine the muffler and saddle interfere. And the muffler hanger does not connect to support the muffler. Am in the process of sorting this out and will update when done.

Update: Dansk 1620607900 is the wrong muffler for a 3.2---DO NOT GET IT. (Can be made to fit with a minor form mod and a custom support bracket.)






Tin ahead of cylinder #3 needs to be cut. Quick solution is to chop this tin off indiscriminately. Time consuming path involves contouring the cut to the exchanger.




Holed-tabs are mounted to the inside seam of each SSI. There’s no connection points for these tabs on the 3.2 in my hands. SSI tab on 4-5-6 side interferes with the case. Can bend this tab out of the way. Alternative is to cut it/them off.






3.2 Oil plumbing requires crossover pipe # 911.103.739.10. Pipe I received is supposedly OEM and was 4 inches too far towards the front of car at end seen in photo. (Photos were taken after pipe was corrected.) Whether every pipe is similar to the one I received is questionable. Other pipes may be better…or worse. Pipe in hand, in original form, interferes with SSI and cannot be connected to the engine as is called for—there’s a tab near the pipe's end that fastens to engine’s tin. There’s another interference below cylinder #3 with the air deflector / baffle. That deflector / baffle can be crushed towards the cylinder slightly to create some clearance between it and the pipe. Because of the bends already in the pipe and the short lengths in that area, bending the pipe there—rather than crushing the baffle–-would be difficult (unless one has pipe bending tools of consequence.) Correcting the 4” of forward positioning calls for applying a good deal of force to the pipe. As such, recommendation is for this pipe bending business to be done with the pipe off the engine. (To do this with the pipe connected to the case would likely tear the case.)

Final adjustment needed here is to bend the mounting tab so there’s a sensible facing of it towards the fastening point on the engine’s tin. There’s a little fine tuning of the pipe’s position available by rotating it (the pipe) at its case-end. What will limit this rotation is the pipe’s proximity to #3 cylinder’s air deflector / baffle.

Other “back date” oil pipe (not shown here) is part # 911.107.729.10. This is “soft connection” that links the crossover pipe to the external thermostat. Cannot comment on the fit of this pipe as the engine is not yet installed. EDIT: Engine installed and running. That is correct oil pipe.




12mm tool supplied with SSIs. Handy but does not work for every nut. Having an assortment of wrenches is necessary. Among them: 12mm offset wrench + 12mm socket with extension + a reaching magnet. Passageways provided for sockets do not allow my 12mm socket on an extension to reach the nuts. There’s a seam in the exchanger on the engine side of these passages that narrows the passage just enough to stop the socket from getting to the nuts. Way around this is to place the socket on the nut (reaching magnet is handy here), then run extension through the passage into the socket. Is good to have the shortest socket height possible. Too tall a socket and getting it onto the nut will be prevented by the narrow space between the nut and SSI. Using an extension that locks to the socket is unwanted here. Once this combo is locked, it may be a challenge to unlock the socket from the extension should the release to do so be within the passage. I tapped my extension's lock open. EDIT: In post 14, John notes there's a SnapOn 12mm socket that fits the passage. I looked at that socket (post 16) and it appears to be a narrower diameter than my current 12 mm socket. TY John.

Antisieze is spec’d for exhaust stud threads. So too is a torque for the nuts but to get a torque on every nut requires special tools—if they even exist. Spec also recommends nuts be tightened after engine’s first full run.

If new exhaust studs are going to be installed, is good to know what thickness the new head-to-exhaust flange gaskets are before setting the studs to a given height. I f'd this up by checking the old and new flange measures. Since they matched, I set the new studs in (with lock) per the old height... then ordered gaskets. Placing the new gaskets, I found the nuts did not make it below the rounding of the stud ends. What I missed was checking the old gasket thickness. Then checking the new gasket thickness (I got thick ones) BEFORE locking in the studs. Not a major problem since thinner gaskets are available BUT they are measurably more expensive than the thicker version.




To install / remove 4-5-6 exhaust valve cover, SSI’s seam at its air intake needs to be bent down.



Stock wiring.


Extended + new sheathing.

Ox sensor’s position in SSI is further towards rear of car compared to its position in stock exhaust. This position renders ox sensor’s stock wiring short provided one wants to maintain the stock run of the wiring through the grommet by cylinder #3. To keep the stock run, approximately 6” of wiring needs splicing in. 16 AWG stranded wire looked a good match for the new Ox sensor I received. There are three wires to deal with. Sheathing over the wires is another consideration. Alternate path is to run the stock wiring up between the engine’s tin and engine bay seal to where it connects.
.

[mikedsilva]

Yep, agree with some of the above.. Installed a new set a couple months ago and had to make a few minor mods

[Discseven]

Somewhere I’ve seen a message saying SSIs no longer come with the ox bung installed. Am not saying this is fact, just that I noticed it. Flag is raised. (Unit I received with the bung pre-installed is etch-dated 02/01/21. Bought them a year ago from this post date.)




Fit of SSIs to Dansk muffler…




All 4 bolt holes are spot on. (SSI as I received---from eBay seller---had the 1-2-3 side flange bent significantly on one end. Doubt SSI was made like this but there’s no telling. Was more likely dropped. Large crescent wrench was put on the bent end. To move this thickness of metal calls for an exalted beating on the wrench. Metal moved slowly. Photo is after adjustment.)




4-5-6 side. Parallel is not quite there. Better fit might have been accomplished had I left both SSI sides loose to the heads, tightened the muffler to the SSIs, then tightened the SSIs to the heads, then removed the muffler for a later install. As I’m doing it here, only the 4-5-6 SSI is loose to the heads. I’d take a belt sander to this if I had one. Filing this by hand… slow progress.

New straps (that wrap around muffler and hanger) were checked. Common note among Pelicans is the supplied bolts being initially too short—ditto. Word is once the straps have been pulled tightly around muffler, the slack is gone so the supplied short bolts do fit, just not to start with.




Grey coating on Dansk looks like primer in photos but it comes off much to easy to be considered anything but minimal initial protection.
.

[Discseven]

Originally Posted by mikedsilva

Yep, agree with some of the above.. Installed a new set a couple months ago and had to make a few minor mods

Mike... afternoon (I think) to you in the River City. Have gone back into valve clearances and timing we were discussing. Will update thread, or start a new one.
.

[Cevan]

Are these made to match the diameter of the exhaust ports of a 3.2? I thought SSIs were sized to fit the 3 liter engines.

[911MANN]

I learned a bit about current production Dansk SSI heat exchangers recently in the planning of my 3.2SS. I got my best information from contacting Dansk directly in Denmark.

In the last 2-3 years, SSI has introduced a slightly larger 41mm model for 3.2L and a bit larger displacements. For my ROW SC, I bought the thin flange 41mm, and it came with no oxygen sensor bung (none needed for CIS).

I "think" they make the same 41mm for the Carrera 3.2, which is fabricated with the bung. I also "think" they make the 41mm in a thick flange version, but I didn't need that and never pursued it. Make sure you consider all 3 variables:
-Diameter (38mm or 41mm, depending upon project goals)
-Thick or thin flange (depending upon your engine & cylinder heads)
-911SC or 3.2 Carrera (engine configuration)

[Otter74]

Great post - thanks for writing it up.

[Discseven]

Originally Posted by Cevan

Are these made to match the diameter of the exhaust ports of a 3.2? I thought SSIs were sized to fit the 3 liter engines.

Cevan... these SSI exhaust ports have "cuffs" that extend beyond the flange matting surface that insert a few mm into the heads. Perfect fit as far as I'm concerned. That is for the part number I mentioned. There may be a different SSI part for 3.0s.
.

[Discseven]

Originally Posted by Otter74

Great post - thanks for writing it up.

.

[dkirk]

I did the same install on my '88 and really like the results. Improved performance and nice sound. If you're interested in cabin heat, here's what I did:

SSI Exhaust – Heater System Workaround

[Nditiz1]

Originally Posted by Cevan

Are these made to match the diameter of the exhaust ports of a 3.2? I thought SSIs were sized to fit the 3 liter engines.

I recently read this too when I was looking up why everyone didn't just run SSI. The hot 3.2 engine i have has BBE and I picked up SSI hoping to add heat, but the older style SSI would hinder my engines power. Good to know Dansk has made them to run on the larger engines. I hate that BBE doesn't use the stock muffler flange.

[Discseven]

Originally Posted by dkirk

I did the same install on my '88 and really like the results. Improved performance and nice sound. If you're interested in cabin heat, here's what I did:

SSI Exhaust – Heater System Workaround

Dave... that's brilliant thinking! (I don't need heat but put the exchangers in for the car's next owner---they may want it.) Printed your photos for future ref.
.

[Discseven]

To allow the omega spring full range of motion, heat exchanger needed to be punched in a bit.

[jjeffries]

Karl, something one of the gurus turned me onto when I put (used, SoCal-produced) SSI’s on my SC: a real SnapOn 12mm 1/4” drive socket will fit.

Best, John

[47silver]

Thanks for the photos. I think i put the o2 sensors too close to the flange. Should put them where you show them

[Discseven]

Originally Posted by jjeffries

Karl, something one of the gurus turned me onto when I put (used, SoCal-produced) SSI’s on my SC: a real SnapOn 12mm 1/4” drive socket will fit.

Best, John

I do believe you have something there John! Hope all is more than well with you in the northland!

Originally Posted by 47silver

Thanks for the photos. I think i put the o2 sensors too close to the flange. Should put them where you show them

[Discseven]

SSI seam bent for omega.




Wrong Dansk muffler (1620607900) has been made to fit. Problems were interference with the saddle and the hanger not fitting the muffler. Together with those points of interests, I standardly questioned what other fitment issues were ahead. Engine---with muf---has now installed with bumper in place and everything seems in order.

.

[vansicklenmi]

Very thorough and helpful. What did you do with the hole in the rear engine tin? or did you leave the blower fan in place?

[Discseven]

Originally Posted by vansicklenmi

Very thorough and helpful. What did you do with the hole in the rear engine tin? or did you leave the blower fan in place?

Vans... sheet aluminum now fills that hole. Brush coated the aluminum with Cerakote Black Velvet. "Brush" coating with Cerakote is not spec. It leaves streaks. It's that or set up all the gear to oxide blast prep then spray that little part. Too many other fish to fry when I was dealing with that to follow Cerakote's spec application. (Engine tin & console is Black Velvet done to spec.) Plate is positioned below engine tin and secured with black screws in each corner. There are nylon spacers between the engine tin and plate. This is to keep the plate from warping when tightening the screws. This is needed because of the waterfall edge in the engine tin.
.

[jjeffries]

Karl are you doing all this work under the veil of darkness in order to keep the HOA at bay? Motor looks superb.

Best as always, John