bleachii

Hello,

I'm the owner of a '79 930 I purchased in 1998. Pre kids I had money to spend on this car and sending it to the shop for a few thousand worth of repairs and leaks wasn't a big deal. Now, not so much

I'm in the process of finally getting the guts to tear it apart and fix the myriad of leaks (oil return tubes, valve cover gaskets, etc). I 'almost' started a few times before and even started a thread on Pelican a few years ago. I will be starting a new thread on my experiences here and probably Pelican as well to ask questions regarding the overall project in the near future. The project began yesterday with about a quart of oil on my garage floor

I wanted to break out a separate question here though to keep it segmented from the rest of the project. I still have all the original exhaust/smog equipment. I'm in the process of removing the heat exchangers and in turn it looks like the thermal reactors so I can access the oil return tubes and valve covers. Not sure the thermal reactors absolutely need to be removed for these but looks like it will help at least with the access to the oil return tubes.

So my question is for any other California '79 930 owners or anyone who understands smog here. Currently my car passes smog with flying colors. t's basically never been an issue. Since it is commonly recommended to get rid of the thermal reactors what will this do in terms of the smog check? If it's a visual only issue I'm pretty sure they have never looked for them so not sure I would be overly concerned. However, I don't want to fail the actual test. Maybe I just need to change out equipment every few years which I could possibly do as well. I'm not due for another smog check until April of 2012.

What do I replace them with? Not sure I can do headers at the moment due to the cost. I really want to stay focused on getting the leaks fixed before I head down the performance/$$$ route. Again....I'm REALLY trying to stay focused here I've already been on the RarlyL8 site but I'm trying really hard.

Thanks for the help.

Brian

aeschen

Not sure about smog in cali. I suspect you would be fine. A good set of used euro headers, would be a cheap upgrad to get rid of said reactors. They come up on pelican for a couple hundred$ every now and then.

Last930

Headers will actually save you $$ in the long run vs. thermal reactors, by making your engine run much cooler. It will reduce heat damage to the heads (valve guides) and cut down on future oil leaks, and the cost and hassle to fix them.

bleachii

Thanks guys...I'll keep an eye out for them and hope to find another CA '79 930 owner who might have done some upgrades.

Rob S

Brian,

Though it's been years since I lived in California, I had a 79 930 that passed smog there with thermal reactor (TR) replacement pipes. I took it to the smog station with those replacement pipes in place, and the technician bent down and looked underneath, mumbled that it had the necessary catalytic converters (!), and passed it on the visual. It then passed the tailpipe sniffer just fine. So, my car was entirely stock, including the air pump, but it had no thermal reactors (and of course, no catalytic converters either) and it passed the test just fine. My advice: get rid of the TRs; they're little ovens that bake everything under the engine, and cause things to fail -- like the very oil return tube seals that are leaking on your car. But keep the TRs in a box, so that in the event you fail the test, it won't be that hard to pop them back in.

The problem with this plan is that you will then have to remove the TRs, which carries some risk. From reading your other thread, it sounds like you were warned about the consequences of breaking off an exhaust stud -- something you want to avoid at all costs. It also looks like you had on your list PB Blaster (which is much more effective than WD 40) and a Mapp gas torch (note that propane will *not* be hot enough to help you). You need to use at least Mapp gas. The best is to use an oxy-acetylene torch, or some torch that has oxygen separate from the fuel gas. Those are the only torches that will (for certain) get hot enough to help you out. I'd suggest you not even try to remove the exhaust nuts without such an aid. Get the nuts cherry red, then unscrew them. Anything short of cherry red is playing with fire (or *not* playing with fire, so to speak!).

Also, be sure that you have a box wrench or socket that very securely fits around each of the 12 nuts, and that you have a way to apply a good force to it to turn the nut. Some of those nuts are much more accessible than others. Some are a real pain (and especially so with TRs in place, if I recall). I've had to custom bend a box wrench or two for some cars to make them work. Don't risk rounding off the hex nuts -- you have one good shot at them if they stay intact. Once you round off the corners, you might be sunk. I'd be very hesitant to use an open end wrench for this purpose. You might also try using a 1/2 in. socket instead of a 13 mm socket. If you can get a 1/2 in. wrench or socket over those nuts, you'll find that because 1/2 in is slightly smaller than 13 mm, it may fit more tightly around the nut to help prevent slippage. It seems that old exhaust nuts often corrode down in size a bit anyway.

I'm not sure if there's a source for those TR replacement pipes. They were kind of an 80s and early 90s thing. But I bet there dozens of pairs of them lying around in garages, attics, basements and shops all over the country. Put out the word that you're looking for them. The advantage to them over just going with headers is that you can keep all the other hardware you own in place, and it would be very quick to swap the TRs back in. Of course, it would be better still to just put on some euro heat exchangers/headers (which are dirt cheap as well - I recently gave mine away from a Euro 78 930), or get some aftermarket headers.

Good luck.

Rob

A930Rocket

Euro or 86-87 heat exchangers. They're the same IIRC.

strudel

I went with SSI heat exchangers when I had the motor rebuilt for my '79 930. They passed smog. The rest of the smog stuff is still in place. The motor is a 3.5 twin plug w/400 h.p @.9 bar and CA smog legal. I wanted the most h.p. and still be smog legal without swapping parts every two years. I'm using SC cams, 3.5 Mahle p&C, twin plug distributor, CIS, SSI's, DP Motorsport i/c and muffler, K27, and 46 Tial w/g. Also got rid of the oil scavange pump. The motor was smogged in the S.F. Bay Area. In CA it needs to pass visual as well as smog, so EFI won't pass.

bleachii

Hey Rob.....thanks a bunch for your input here. Gives me a good CA path to follow. Looks like from my other thread and on Pelican I need to remove the TR's. So, will be following your procedure above. I'm still looking at options for replacing the TR's but I like the replacement pipes as a quick fix if I can find them.

Strudel...when you say the rest of your smog stuff are you saying you have TR's? Or are the SSI's headers? Think I'm missing something.

strudel

The SSI's are heat exchangers (I wanted heat) and replace your t/r. The air pump and plumbing, and some valve that runs from the back of the motor to the muffler (decel?) were retained. The grey pipe coming out of the right side of the muffler runs to the valve. The grey pipes below the sump pump run from the air pump to the heads. All needed for the smog check.

bleachii

Thanks for the explanation and pic Strudel. Makes sense now. I had not seen the SSI setup before. Although I don't recall that grey pipe from the muffler to the valve? I'll have to check that out. I pulled my muffler last summer and put on a Zork but I know I didn't remove any plumbing to the muffler.

bleachii

OK Rob....this weekend it looks like I will be attempting removal of at least some of the TR nuts. I'm printing your post above to help. Once again appreciate the detailed instructions!

wleon

My 79 930 turbo was no problem to smog without thermal reactors. just run it a bit lean and hot to the smog station. I used to have my mechanic adjust it for smog before taking to the test station and it always passed. Had to readjust once it was smogged. Its been a couple of years since it was smogged as it is track only now but i dont think it could have changed much since then.
*****

strudel

Looks like it has. Look at the response by Zimmerman on this thread. http://forums.pelicanparts.com/porsc...-legal-ca.html