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Slippery Slope Expert
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S/C P/C Sets
I am rebuilding a 1982 SC that had been sitting up for at least 15 years. I had to tear the engine down because of the usual broken head stud issues and I am having trouble coming to grips with the piston/cylinder issue, i.e. what to do about replacing the cursed Alusils. This is exacerbated by the fact that the replacement P/C sets for the '82 SC seem to be by far the most expensive out there to replace! Ordinarily this might be a no-brainer as far as modifications go, but there are some extenuating circumstances.
1. Because the area I live in lives under some "special," draconian smog rules, this car is subject to smog testing even though it is 31 years old! I could always license it as an antique and sidestep this issue, but I would prefer not to. 2. The P/O had had the engine backdated for performance, so I have the large port heads with CIS to match. He also had installed earlier HE's and a factory sport muffler; all this was before the emissions testing was started here. I do have two complete cat exhaust systems and muffler, and also the '82 CIS. I do not, however, have the original small port heads to go between those systems. What I would like to do is rebuild the engine using the large-port heads and CIS intake, the cat system with cat, then use the Tbitz injection. I suspect this would pass emissions OK (there is no configuration inspection, just the sniffer in the tailpipe) So, suggestions are in order. Should I bite the bullet for the swirltop CIS P/C set, or would something else fill the bill as well or better for somewhat less money. I know it's not going to be cheap - these things never are. But I think the price of the CIS P/C sets compared to the others is a bit much. Ideas? Opinions? |
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Registered
Join Date: Oct 2008
Location: Nash County, NC.
Posts: 8,502
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I would just reuse what you have unless you know they are defective. I ve been very successful reusing the alucil, not that I want to, but Mahle used isnt always available.
Bruce |
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Registered
Join Date: May 2004
Location: Boulder, Colorado
Posts: 7,275
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A CIS without cats or smog pumps can be leaned out enough to pass smog. At least smog where I live. Why not rebuild to stock, taking care of head studs, maybe having a valve job done, and at most having a machine shop do careful measurements to see if your old Ps and Cs are within reuse spec?
As to rings, I'd search for that on this website - Bruce can tell you if you can rering or have to use the old rings unless they have obvious defects? Then take it to a place with the machines to measure what your smog testers measure, and have them adjust the CIS so it passes. Also have them sell you the tool for doing this adjusting, and have them tell you how far clockwise you should turn the adjuster back if this makes the engine run too lean for its long term health. |
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Registered
Join Date: Jan 2004
Location: CT
Posts: 11,551
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My '83 SC with SSI's and sport muffler used to pass smog every year in CT. Just as Walt described, I would lean it out before going for the test and then richen it back up afterwards. If your state requires that the Cat be present, then you may need to go back to the original exhaust for the test.
Alusil cylinder bores can be reconditioned if they are in spec. PM me for more details if interested.
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Tom Butler 1973 RSR Clone 1970 911E 914-6 GT Recreation in Process |
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Slippery Slope Expert
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This is very interesting, because the "conventional wisdom" up until now, seems to be that you can't reuse Alusils; just rolling the dice if you do.
The emissions I need to pass here is 220ppm HC, 1.20% CO. No configuration test, nothing but the sniffer up the tailpipe. Do you guys see any issues with that and CIS (but I'm still leaning towards the Tbitz, "just because.") |
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Registered
Join Date: Jul 2013
Posts: 1,106
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You can have the cylinders re-plated by Millennium or others and run an aftermarket piston. This option is a little less then 2k total...
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Registered
Join Date: May 2003
Posts: 3,346
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Quote:
-Andy
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72 Carrera RS replica, Spec 911 racer |
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