1985 400i 5 spd / Long overdue / 12k Service

Checked the resistance on the 12 plug wires. Two were open circuit No. 8 and No. 9. Here are the Ohm readings after. The root cause of the failure was arcing on the small metal needle that bridges the circuit from the wire core, over to the steel connector. Note the arc'ing spot.
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I media blasted the headers this morning. It was perfect timing as my favorite UPS driver was just dropping of the Cerikote Cobalt ceramic coating.
Here is the blasting process:
https://youtube.com/shorts/Rg_hvEOE5

After the blasting process, I took advantage of being back in the metal fab shop, within a few feet is and 18'' version of a disc grinder with a very stable and flat grinding wheel. A few quick passes and it flattened out all the flange faces.

After a quick final airblast they all got two complete coats of the cobalt colored ceramic coating. This is an air cured product and it is dry to the touch after about 45 minutes. (outside temp today was 75 degrees F). I will let them dry for two days as I am still waiting for exhaust manifold gaskets from Superformance.
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After checking the brushes on the starter and lubricating the armature and bendix gear. I reinstalled the starter keeping the bottom nut loose.
That upper bolt is buried. It took careful fingers and a specialty 17mm box end to get that tightened. Header has to be out of the car.

The heat shield originally used asbestos. I comically tried to find some more as this was still available 5 years ago during and E Type Jaguar restoration. Absolutely none was available so I selected a 1200 F insulation from Mc Master Carr. This got cut to size and pinched in placed and reinstalled.
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Forgive the dumb question of the day, but what are the 2 curved pipes at the connection of the headers to the exhaust, outboard of the main pipes? They seem to be present in some pictures but not others.
My 412 has somewhat less of the exhaust than it used to have, and to great effect, too, but my headers don't seem to even have the connections for these smaller pipes.
It all adds to the mystery of what my car should actually have in the way of an exhaust. It passed CA smog recently with the small cats you see in the picture, but at some point another smog tester might fail me for not having whatever else is supposed to be there. I can't find a CARB sticker anywhere so I have no idea. Image Unavailable, Please Login

 

Follow-up question - what are the hexagonal pieces on each downpipe? Top right of my picture.

The headers on the cars are a work of art, aren't they?

If only they were equal length, the significance of such a configuration I have only recently heard, pun intended.

 

You mean the balance pipe? If so, these were previously discussed in this very same thread.

These were used to tune the k-jet.

 

Ah, I had thought the balance pipe was referring to the cross connection "balancing" between the two main pipes.

What does the actual balance pipe actually balance then? Mine runs like a dream without them.

 

Presumably balancing pressure inside the muffler so as to allow better flow in the slotted portion of the tube and reduce stress on the muffler (all this with question marks...) .

Some cars do not have them, in some other cars they are "tapped".

 

It is my understanding that these smaller 'balance pipes' were eliminated on the 412 models.

 

The SPCs show that they got rid of the "balance pipes" on the 412 (only present on 400).

Those are typically referred to as the "exhaust sampling ports". They give a place to measure the exhaust gas from each individual cylinder to investigate if there's a problem (they are very rarely used). The actual hex headed threaded plug is Ferrari PN 110860 -- used on many F models.

 

I found myself being mesmerized by the beauty of these six trumpet horns. It's a shame to hide them with the plenum and throttle body.

Second pic: that is a lot of exhaust plumbing.
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I see you have added universal cats on your 412. How is the sniff test, and what are your CO NO values?

I will be installing cats as well as the smell is very pungent, I use many underground parking garages and without a cat is unusable.

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See attached for the emissions.

The engine had to be leaned out a lot, which was a function of adding the cats and would have been done irrespective of the smog anyway. I previously put on 2 in/2 out cats and they were annihilated within 500 miles as the car was running rich.

Running rich, without cats, with only the small mufflers you see to the rear of the new cats and straight pipes aft of the rear wheels, manual transmission and the confidence to wring out a recently rebuilt engine, is a deeply stimulating experience and IMO the most fun you can have with your clothes on and/or without psychedelics.

There is a definite loss of power with the cats and leaning out, perhaps 5%, but to my relief the car still runs very smoothly.

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Some days on the project are more gratifying that others. Some days are immensely gratifying.

Before
and
After
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Did you use 2 or 4 2inch cats?



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4 inch.

 

2inch cats, and 2 on each side?

Did you get them installed and did you notice a difference in the exhaust smell?

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You and Britward may be talking about two different "sizes" -- the size of the pipe diameter (2") vs the OD size of the cat body (4").

 

1 x 4 inch Cat on each pipe, and yes, made a significant difference in the smell.

Apologies for taking this great thread in a different direction.

 

Great, I will be getting mine installed next week. Will make a separate thread.

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One last look before the header heat shields go back on. It's a shame to hide these beautiful header designs.
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-Fresh gaskets on the back of the cam covers
-Fresh wrinkle finish on the heat shields
-What appears to be the original 1985 Air filters - comical, yet sad.
-Powder coated battery tray
-Disassembly and cleaning the crystalized gears on the windscreen washer pump before the battery goes back in
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Replaced all of the Tyco / Amp connector boots on the wiring harness. All of them were cracked all the way through.
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How did you replace the boots and where did you source them?

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@360modena2003 You will need to purchase a AMP / TYCO pin extractor. Then, very carefully, push the barb down on each pin inside the connector housing and extract each pin. Note the color codes and pin orientation. Install the new boot with lubricant. Reinsert pins. I would avoid the temptation of the boots available on Ebay and Amazon. The lead times from China are exceedingly long and the fit quality is poor. Digikey has quality boots, that fit.

Digikey stocks the boots:
https://www.digikey.com/en/products/detail/te-connectivity-amp-connectors/880811-2/2054433?utm_adgroup=Rectangular Connectors - Accessories&utm_source=google&utm_medium=cpc&utm_campaign=Shopping_Product_Connectors, Interconnects&utm_term=&utm_content=Rectangular Connectors - Accessories&gclid=CjwKCAjwx_eiBhBGEiwA15gLN-uNLiwNF2CZ9gXcIQffdF2HL__65rJN9gUvSFppswygOhnf75oFghoCa9AQAvD_BwE
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