Today (Wednesday) was downpipe day. I’m also stuck because a thread gave up in the clutch/gearbox bellhousing last night when I decoupled it from the old engine.
One of the three reverse-bolts was the wrong one, 45mm in length instead of 60mm. The top two should be 60mm bolts. That’s one of the three bolts that make you wonder what they were thinking when they designed the engine-gearbox coupling. With 15mm of length missing, only about 5-6mm were actually biting.
The thread came out when I removed the bolt. The curious thing is I never had two 60mm bolts. It’s about the 3rd time I remove this gearbox and I never had a 60mm bolt left. Small mystery.
I ordered the correct bolt, a cool $14.50 from Ford, and a M10 thread repair kit, TIME-SERT like, not helicoil. I will be installing a M10x1.5 14mm-long steel insert. That should do it: the torque is 47Nm.
I’ve noticed the cat converter substrate was cracked on my stock downpipe. It was probably going to crack more so I bought a catted aftermarket downpipe to replace it.
The one that won was the one that was in stock and shipped on the same day with 2-day shipping that did not cost an arm: a
CP-e ordered from CJ Pony. High-flow they say. They also claim 5% power increase potential. The new cat is much smaller with larger cells and a metallic substrate that has very thin walls so it’s apparently less obtrusive but the stock cat has a much larger, oval surface so I don’t know for sure. There are provisions for a 2nd lambda sensor before the cat, for those who want to use a standalone lambda monitor. The downpipe comes with a plug to block the extra port if not needed, but no washer for the plug so I added a copper one.
The downpipes is not a work of art but it’s bigger: about 73mm I.D. straight from the flange vs. 65mm for the stock one. It also feels robust and fits in the stock hanger rubbers, and it’s a bit lighter than stock, about 0.9kg or 2lb less, although I didn’t weight them. It’s a direct-fit, no mod required. They moved the O2 sensors bungs a bit but there is no clearance issue on the car.
It couples with a stock catback and the problem (not their fault though) is the coupling is only 63mm I.D. due to the way it works with the Ford collar. This means a 3” (73mm I.D) pipe reduces to 63mm just for the coupling, then returns to 3” - This is something that might be worth fixing one day, namely redo the downpipe-to-catback interface so it does not reduce the inside diameter by 10mm and the section surface (and flow) by a whopping 25% when coupling a 3” downpipe to a 3” catback.
I shielded the cat and the initial part of the downpipe the best I could with some leftovers insulation material I had, to reduce the heat released in the engine bay. Not museum-grade work but it’s a downpipe.
Note the stock downpipe has a gratuitous restriction held for about 10mm right after the flex section, before the hanger. Another small Easter egg from our friends at Ford 😋
I got the bolts and the repair kit in the morning. Ordered on Tuesday night, back on track on Thursday.