| Author | Message | ||
| Paul Hill (348paul)
Junior Member Username: 348paul Post Number: 167 Registered: 12-2002 |
The company that is doing a restoration on one of my cars had a Mercedes 600 in about a month ago - The cat had fallen apart and part of it sucked back into the engine. It scored the bores of the block rendering it useless. A new bottom end had to be purchased at a cost of �20,000 - Frightening stuff!! Paul | ||
| Jim DeRespino (Jimbo)
Junior Member Username: Jimbo Post Number: 68 Registered: 10-2001 |
An easier way to clean out the pre-cats is to take a big masonry bit (I used a 3/4" diameter x 12" long bit) in a 1/2" hammer drill. STEP 1 - Put pre-cat in vice STEP 2 - Insert drill bit into pre-cat STEP 3 - pull trigger and hold on It took me about 20 minutes to clean out each pre-cat and the porcelain mesh makes quite a bit of dust (wear gloves and eye protection) but it is very gratifying to watch that junk fly out. Afterwards I bead-blasted the whole thing and coated it with Eastwood's stainless steel exhaust paint. Over 4000 miles later it's still the prettiest part of my exhaust. Except for the Tubi. Or the stainless steel test pipes. Or the chrome exhaust tips. Well, anyway, it still looks nice... | ||
| barry castelete (Bazzis)
New member Username: Bazzis Post Number: 11 Registered: 7-2002 |
Are these precats on all 512TR's or just US spec cars?? | ||
| Henryk (Henryk)
Member Username: Henryk Post Number: 587 Registered: 8-2001 |
Jeff: I would recommend everyone remove the interior of the pre-cats. After use, the material inside cracks......mine was in several pieces. It would appear that it was one colid piece, when new. Some of the pieces even where lying transversely, with the holes at 90 degrees to the flow of gas. This can only add restriction. | ||
| Jeff Green (Carguy)
Junior Member Username: Carguy Post Number: 205 Registered: 10-2002 |
I always wondered what was in those things! Practically a cat-convertor by itself it appears. I agree with your ideas on exhaust mods. I'm having stainless pipes fab'd to replace precats and cats. But I hadn't planned on splitting open the muffler for any baffle mods. But I have heard that others have done this. And when your done you'll see performance gains every bit as good, if not better, than those outrageously expensive aftermarket systems. If my mods don't produce the sound and effects I want, I too will clean out the muffler. More power to ya Henryk! (pun intended) | ||
| Henryk (Henryk)
Member Username: Henryk Post Number: 586 Registered: 8-2001 |
Just removed the exhaust on my TR, to make straight by-pass pipes to replace the cats......for testing purposes only, of course!!!!!! I then pondered on what to do with the pre-cats....one rattled when shaken, and a few pieces of some strange material came out. Looking into them there was material broken, in several shapes. I couldn't get it all out. Wanting this out, I removed the outside, thin cover, used the plasma cutter to cut out a 3"X5" opening plate into the pre-cat, and proceeded to remove the interior......a steel mesh encircling the main body, with a light material with numerous holes lenght-wise, about 1mm each.......100s of these. After removal, I then MIG welded the plate back on..........overall: LESS restriction. MY next project will be to cut open the stock exhaust, remove some baffling for even less restriction. Then I will fabricate the straight pipes. Overall sound should improve, and eliminate the potential for fire. Any thoughts? Thanks   |