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--- blog:911_exhaust [2022/07/10 20:14] – [Removing Headers] john
+++ blog:911_exhaust [2022/08/17 15:22] (current) – [Repairing & Repainting Parts] john
@@ Line 170: / Line 170: @@
 **Cylinder #1**
-{{:blog:cars:911:img20220710161903.jpg?300|}}
+{{:blog:cars:911:img20220710161903.jpg?300|}} {{:blog:cars:911:img20220710162429.jpg?300|}}
 **Cylinder #2**
-{{:blog:cars:911:img20220710161910.jpg?300|}}
+{{:blog:cars:911:img20220710161910.jpg?300|}} {{:blog:cars:911:img20220710162434.jpg?300|}}
 **Cylinder #3**
-{{:blog:cars:911:img20220710161916.jpg?300|}}
+{{:blog:cars:911:img20220710161916.jpg?300|}} {{:blog:cars:911:img20220710162439.jpg?300|}}
+Looking at the three cylinders, from left to right; 1, 2 and 3:
+{{:blog:cars:911:img20220710161956.jpg?400|}}
+General condition of the exhaust system is still very good - a few oil stains here and there, from the recent oil pipework replacement, as well as all of the release oil I've been using. A good clean up is needed, but there's no corrosion and no cracks from what I can see.
+{{:blog:cars:911:img20220710162448.jpg?200|}} {{:blog:cars:911:img20220710162453.jpg?200|}} {{:blog:cars:911:img20220710162500.jpg?200|}}
+{{:blog:cars:911:img20220710162545.jpg?200|}} {{:blog:cars:911:img20220710162549.jpg?200|}} {{:blog:cars:911:img20220710162708.jpg?200|}}
+I also took the opportunity to pop off the intake hose from the turbo and check for wear or damage; fortunately it is in exceedingly good condition for an original, 1992 turbocharger - no side to side or in/out float //at all//, the shaft also spins extremely freely, even taking a good second or two to spin down after spinning it gently by hand. The shaft and bearing surfaces must be in very good condition. Also no oil drips in the intake elbow, so crankcase pressure/seals would also appear to be good.
+{{:blog:cars:911:img20220710172050.jpg?400|}} {{:blog:cars:911:img20220710172257.jpg?400|}}
+One thing that was bugging me was why the significant exhaust leak. With both headers off I lifted them up on the bench and tested for levels across each of the three exhaust flanges... what I found is probably the most likely cause of the leak:
+{{:blog:cars:911:img20220710163142.jpg?400|}} {{:blog:cars:911:img20220710163252.jpg?400|}}
+The left hand bank shows that cylinder 2 exhaust flange sits around 1mm //lower// in height than the outer two flanges (1 and 3), and the right hand bank shows that cylinder 5 sits around 1mm //higher// than the outer two flanges (4 and 6) on that bank. It's not a lot, but since these aircooled turbos only use a basic sealing ring / crush washer to seal against the head....
+{{:blog:cars:911:img20220710163004.jpg?200|}}
+.... then that's probably enough discrepancy in tolerance to have all of the exhaust flanges not mate to the head properly. The only way to resolve this is to take a file to the flanges and file them down so that the straight edge sits perfectly on them all.
+==== Removing Engine Tinware ====
+Not strictly necessary, but since everything else around the exhaust is coming off, it made sense to strip these rusty parts off while access is easy(er).
+In order, it seemed easiest to remove the right and left side pieces first, then you get a (little bit) better access to the remaining corner screws of the rear engine tin. Obviously with the engine still in the car I did //not// look to remove the other pieces of tinware which are on the front/gearbox side of the engine.
+{{:blog:cars:911:img20220712212740.jpg?400|}} {{:blog:cars:911:img20220712212748.jpg?400|}} {{:blog:cars:911:img20220712212755.jpg?400|}}
+{{:blog:cars:911:img20220712212807.jpg?400|}} {{:blog:cars:911:img20220712213139.jpg?400|}}
+Clearly, very, very rusty. But fortunately there are no major holes - only certain of these pieces seem to be available from new (at least in 2022), so if you had to replace them all it would either be very expensive, or rather difficult to track down old stock. I'll be media blasting them and repainting before refitting.
+With the engine tin out, there's much better access to the upper (inlet) valve/spark plug area, so it makes sense to change plugs, replace cam cover gaskets and do any valve adjustments at the same time. In my case I've got a bit of a leak from the right hand, lower cover, so I'll be replacing all gaskets, checking valves and repainting the covers before I refit them.
+{{:blog:cars:911:img20220712212649.jpg?400|}} {{:blog:cars:911:img20220712212704.jpg?400|}}
+{{:blog:cars:911:img20220712212637.jpg?400|}} {{:blog:cars:911:img20220712212722.jpg?400|}}
 ==== Removing Catalytic Converter / Turbo ====
+===== Repairing & Repainting Parts =====
+First of all, cleaning the bumper brackets, engine tin, supports and hot air ducts:
+**Blasting & Cleaning**
+{{:blog:cars:911:img20220724113601.jpg?200|}} {{:blog:cars:911:img20220724123928.jpg?200|}} {{:blog:cars:911:img20220811113205.jpg?200|}}
+{{:blog:cars:911:img20220724113623.jpg?200|}} {{:blog:cars:911:img20220724113634.jpg?200|}}
+{{:blog:cars:911:img20220724150927.jpg?400|}} {{:blog:cars:911:img20220812121648.jpg?400|}} {{:blog:cars:911:img20220814144824.jpg?400|}}
+**Primer**
+{{:blog:cars:911:img20220812121615.jpg?200|}} {{:blog:cars:911:img20220812121627.jpg?200|}}
+{{:blog:cars:911:img20220814150839.jpg?200|}} {{:blog:cars:911:img20220814150845.jpg?400|}} {{:blog:cars:911:img20220812121621.jpg?200|}}
+The rear engine tin panel is the only part that needs a repair. Fortunately everything else cleaned up well.
+**Paint & Clear Coat**
+{{:blog:cars:911:img20220812162327.jpg?200|Engine tin, left side}} {{:blog:cars:911:img20220813121548.jpg?200|Engine tin, right side}}
+{{:blog:cars:911:img20220813121555.jpg?400|Wastegate vacuum hard-line pipes}}
+{{:blog:cars:911:img20220813121600.jpg?400|Bumper supports, large}} {{:blog:cars:911:img20220813121639.jpg?225|Bumper supports, small}}
+{{:blog:cars:911:img20220813131217.jpg?400|Hot air ductwork}} {{:blog:cars:911:img20220814150835.jpg?225|Hot air ductwork}}
+Blower motors are fine, but dirty and a little corroded, so they were stripped down, cleaned, new screws and washers fitted and given a coat of clear lacquer to try to keep them from rusting any further:
+**Stripping Blowers**
+{{:blog:cars:911:img20220816142604.jpg?400|}} {{:blog:cars:911:img20220816143700.jpg?200|}}
+**Cleaned, sprayed and re-assembled**
+{{:blog:cars:911:img20220816163650.jpg?200|}} {{:blog:cars:911:img20220816163657.jpg?200|}} {{:blog:cars:911:img20220816164017.jpg?400|}}
 ===== Replacing Gaskets & Seals =====
@@ Line 195: / Line 275: @@
 {{:blog:cars:911:img20220621134311.jpg?400|Wastegate gasket, 2x needed}} {{:blog:cars:911:img20220621134332.jpg?400|Turbocharger to cat gasket, 2x needed}} {{:blog:cars:911:img20220621134511.jpg?225|Collapsible oil-return tubes}} {{:blog:cars:911:img20220621134321.jpg?225|Turbocharger to exhaust gasket, 1x needed}}
-{{:blog:cars:911:img20220624180756.jpg?225|Replacement wastegate spring}} {{:blog:cars:911:img20220624180841.jpg?225|Wastegate service kit}}
+{{:blog:cars:911:img20220624180756.jpg?225|Replacement wastegate spring}} {{:blog:cars:911:img20220624180841.jpg?225|Wastegate service kit}} {{:blog:cars:911:img20220812130334.jpg?400|Fabspeed replacement exhaust tips}}
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