Oliver Gets a Cat (Part 1)

No, this isn't a children's story. Today, I will start to go through the fun of integrating a catalytic converter into the after-market exhaust in my 1978 MGB (named Oliver). Like so many projects these days, I have started some, but I am either waiting for parts or time before I can get it completed. In this case, I am waiting for parts.

Before I Start
In light of everything that is going on with CoVid-19, and the historically unprecedented unemployment and widespread hardship, I recognize that a blog about fixing up an old car or VW bus is fairly frivolous. In fact, some might be offended that I am not focusing my energies on helping our fellow man. That is a fair observation, and I apologize if you're offended. There is so much sobering news out there, perhaps this is my little bubble of normalcy.

In full transparency, for most of the projects waiting for my attention, I acquired 99% of the parts over many years. I am not tossing money around for parts like I have some massive pile of cash. The side marker housings from the last couple of posts, for example, had been in my garage for over 10 years. At the other end of that spectrum, I got the catalytic converter, and the spare exhaust pipe for this MGB exhaust project last Fall. Still, I will need a part here or there to complete the work on these projects, like electrical bits or pipe/hose clamps, etc. Also, there are times when cars fail, requiring a part, as is the case with K'Lack at the end.

I understand there are some who feel life's burden very acutely these days and the cost of a few car parts is a loaf bread and a can of tuna for someone else. Again, I hope this blog doesn't create animosity or frustration; my intent is the exact opposite: a respite from the seemingly endless stream of bad news and personal loss in the form of some guy writing about his often odd-thought ways he tries to keep his old cars running, personalized and comfy.

No Ring in that Bell

morning walk during
CoVid-19 lockdown

Recall a couple of years ago, the exhaust system in Oliver was failing. The head on the MGB has a shared middle exhaust port, and the slap-together exhaust manifold had a very rough angle on it. It looked bad and performed worse. The muffler had failed, so I pulled a full-on shade tree move and hooked up a make-shift muffler with a soup can to get through emissions. (see MGB Exhaust Re-Do Part 1) That was May 2018, and what a hoopdie Oliver was. Shortly afterwards, I purchased and installed a Bell stainless-steel exhaust. Prior to installing it, I had the whole thing ceramic coated. While most might think this was overkill, I did it for 3 reasons:
- to reduce the overall temperatures for more occupant comfort
- help the exhaust quickly flow out of the system because the exhaust stayed hotter and the inner walls are perfectly smooth and
- to change the note of the exhaust so it didn't have that high-piercing ring for months while the soot slowly built up inside the tubes... which is why a "seasoned" exhaust has that nice low note

I went through the fun of the install in MGB Exhaust Re-Do (Part 2).

No Cat Either
The drawback to this set up is that eventually I would have to introduce a catalytic converter to pass the every-2-years emissions test. That test is rapidly approaching, so I had to figure out how to integrate a catalytic converter (cat). Bell does not offer an option. So, I started where I began: lying along side the bottom edge of the driver door, trying to imagine where a cat could fit. In a bit of irony, Schmidty, the shop kitty, was more than willing to lie on top of me while I tried to figure it out. I found a basic catalytic converter on eBay (in early November, 2019): 1-3/4 inch diameter hole, 4-inch diameter stainless steel Thunderbolt cat, legal in 49 states (not CA, of course). This was the shortest and the smallest diameter cat I could find that didn't look like complete trash and had lots of fairly positive reviews. An added personal bonus: it was made in the USA.

Locating a Cat

figuring it out

Knowing that a catalytic converter is more efficient the closer it is to the point where the exhaust is created (due to faster warm up and longer high temps of the cat), I first looked to put it right where the header ends. You can see the end of the header in the left edge of the picture on the right. This, unfortunately, would abut a bit of frame just aft of the end of the header. So, I looked at a spot about a foot further back, where there was about 7 inches between a frame rail and a transmission support. While not as far forward as I'd like, and, instead almost directly under the driver's knees, this is still the best, possibly only, location. I found and ordered a replacement section of pipe for that spot from a small shop in Britain (in October 2019). Once I was ready to get after this project, I checked that the pipe would easily fit into the ends of the catalytic converter. I then suspended it from the original pipe with painter's tape and located where along it's length the cat would fit, and then where I would need to make cuts. I applied wide painters tape around the pipe near those cut points and checked them again and again and again. I marked those spots with a pen, and extended them all the way around the pipe.

Integrating a Cat

confirmed cut-marks

With the cut marks checked and re-checked, I took measurements of where the cuts would go for posterity (see picture). The longer, straight pipe is just over 11-1/2 inches long. The next cut is 18-7/8 inches further down. These measurements are taken from the front-end (front is front) of the pipe. I then took out my hacksaw and cut the pipe into 3 pieces at the marks I had made. To improve the cinching-down of the cat onto the pipes, I cut 4 channels (half-an-inch deep) on each end of the catalytic converter so the end of the cat will slightly collapse when compressed by the pipe clamps. I fit the 2 pieces I intend to keep into opposite ends of the cat and then offered it up to the header. Without clamps or anything, it will be a nice solid fit. I will, however, need a support for the pipe at the rear of the converter since there isn't one already on the MGB until after the center resonator. That would make for a long stretch of unsupported weight.

With a flat file, I took down the burrs where the cuts were made and then boxed and shipped the 2 keeper-pieces to the local coating company I used before (Finishline Coatings in Milwaukie, OR). I didn't necessarily need to get them coated, but I thought that having the whole system the same, except for the cat, would look and perform better. Besides, with the Covid-19 thing killing our local businesses, a little job like this might make a huge difference to a small shop like theirs. Based on the correspondence I had with them, it really did make a difference.

And Now, We wait
So, this is as far as I have been able to get. I am waiting for the pipes to come back from ceramic coating, grateful the owner is able to work through the Covid-19 lock-down. Regardless, I am patient and recognize the health of the fine folks at their shop is more important than a speedy completion of my pipes.

K'Lack Back but Lack

P0183 = fuel temp sensor bad

Before I go, one last item. A few weeks ago, we got K'Lack back from the transmission shop. It had been rebuilt with the wrong kit, and after 10 weeks of waiting and diagnosing, it was rebuilt with the right kit and returned to us. No charge for the rework, but when they re-installed everything, they didn't notice that they broke the evil plastic coolant outlet flange. We would start to drive it only to have the coolant light flash at us. We'd pull over, see the coolant was low, fill and repeat. I replaced the flange easily enough (remove the air filter housing for easier access), and everything seemed fine. Until the check engine light (CEL) popped on to let us know that the fuel temperature sensor, which was throwing codes last Fall, still needs to be replaced. Sigh. So, I pulled Oliver off the road thinking we had 2 viable cars, we really only have one. I will replace the sensor and we'll be back in business soon.

Thanks, as always, for following along. I hope you have found ways of amusing or entertaining yourself while on Covid-19 lockdown / shelter-in-place. Hopefully, the 10 minutes it takes to read through my musings helps entertain. While being at home is a blessing for many of us, it is also a time to be more patient with yourself and your loved ones. That may be easier said than done, I know. I am talking walks, stretching, trying out yoga, etc. to extend my patience. It seems to help. Take care, wash your hands, wear a mask and, as always, more to come--