Exhaust

[bpossel]

Hello All!

 :?: Question... Should there be washers between the down pipes and the exhaust manifolds?  

 :?: What is the correct setup (bolts, washers, etc.) for connecting the down pipes with the exhaust manifolds?

  Thanks in advance for your replies!

Bob

bpossel  (Memphis, TN.)
'71 280SL  /  '97 E320

[jsaylor]

Bob,

They go between the dakine and da uder kine, ladat.

Aloha

Jim Saylor
Kauai, Hawaii
'65 230SL

[Cees Klumper]

Hi Bob - for that connection, it is very important that it is a tension-fit, i.e. that there is space between the flange on the downpipes, through which the 3 bolts go that connect and hold it to the manifolds, and the manifolds. It's the tension that will keep the connection tight. There is a metal, thin, gasket-like washer that goes between the pipe and the manifold, and I would expect it's necessary to really seal the connection. Sometimes, people put two or three of these gaskets in place, to ensure a tight fit. The nuts to be used are copper or brass and they have a slit in them to make sure they lock. Don't use anything other than those original-style nuts, because anything else may not hold properly, with all of the vibration, intense heat/cooling off action and so on. You want a tight fit to minimize noise levels and prevent you from getting dizzy while driving around.

Cees ("Case") Klumper in Amsterdam
'69 white 280 SL automatic

[bpossel]

Hi Cees, Jim.

Jim, funny !  Aloha!

Cees, thanks.  You answered my concern.  No washer between the manifolds and the downpipe flange.  Only the crush ring.  Then use bolts with the copper nuts to compress the 2 ends together.  I also learned this info from Gernold last night.  Once it's all tight, no leaks, I wont have an excuse for being dizzy anymore...

I have some thick flat washers (look like chrome/stainless?) that I will use prior to the copper nuts that hold the manifold/intake to the block.

  Thanks again!
Bob

bpossel  (Memphis, TN.)
'71 280SL  /  '97 E320

[RCS Coupe]

Minor additional point on the exhaust pipe fasteners: the six bolts are standard-thread M8 size with a normal 13mm hex head. The proper nuts are slightly smaller and require a 12mm wrench/socket. If you try to use a standard-sized (13mm) nut, a regular socket will not fit completely over the all of the nuts due to interference with the manifold casting.

When doing the pipes, give yourself some operating room by first removing the starter and the intake manifold heat shield.

Side note: The same one-hex-size-smaller than standard differential is encountered with the manifold-to-cylinder head attachment nuts, which are also the same special copper-plated steel self locking type used for the exhaust pipes.

Ray
(268)Green 250 Coupe

[bpossel]

Hello!

I finally got my exhaust system back on my car and drove it yesterday for the 1st time in many weeks.  It's amazing how fun it is to drive!

Just wanted to update you on what I did.... in case you want to do the same, or would like any advice before you start this project...

Summary:
1. Removed my entire exhaust system.  My system is all one piece (welded).  Rear & middle sections are stainless; downpipes are steel; both pipes connected.
2. Sandblasted the down pipes and painted with high temp silver colored paint from Eastwood.
3. Removed exhaust manifolds and had them ceramic coated.  May not be "OE correct", but they do look nice now.  See before and after pics, attached.
4. Removed and cleaned, buffed, intake manifold (see attached pic).  I did not take a "before" pic, but it was filthy!  Lots of carbon build-up inside the intake.  Took lots of cleaner and elbow grease to remove the crud!
5. Removed and replaced starter with new, smaller version.  Much easier to install the smaller puppy.
6. While car was out of service for soooo long, I also had my wheels sandblasted & powder coated...  much nicer now, even though you can't see them with the hubs on...

Overall a fun project, but you need to have patience!  It was very challenging removing and installing the 1-piece exhaust system while the car was on 4 jack stands.  The hardest part is maneuvering the entire system around the idler arm housing (had to remove the idler arm to get the longer end of the pipe around it). To do this, I had to swing the entire rear of the exhaust system to the left (drivers side); jack up that side to remove the jack stand; swing it past the rear wheel area; lower back onto the jack stand; swing system all the way perpendicular to the car.  Then have the wife lift, lower, turn, screem, shout, ....  until we got the booger out.  For some reason putting it back in was a bit easier.  Not sure why?  This was like one of those puzzles when you were a kid, where you unhook 2 crooked, twisted nails...  then put them back together again...

Here are the pics:

Download Attachment: before.jpg
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Download Attachment: after1.jpg
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Download Attachment: after2.jpg
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Download Attachment: intake.jpg
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Download Attachment: wheelscoated.jpg
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