Oliver Gets a Cat (Part 2)

This is still not a children's story. Instead, today we finish integrating a catalytic converter into the Bell header-through exhaust system I installed onto our 1978 MGB, Oliver. Since my last post, I have learned that our Summer Solstice music festival, 4Peaks, is cancelled this year. While not surprised, this summer will be our first in years without a trip in Hapy to see some music. Yes, that is a total first-world problem and others have far bigger issues to contend with than some music festival. Gotcha. It is still disappointing for me, my fellow patrons, the vendors, the hosts, and the musicians. Anyway, where was I?

Pipes Arrive
I mentioned last time that I got a replacement section of pipe shipped from Britain. I measured, re-measured, etc that pipe and cut it into 3 pieces, 2 to keep, one to toss. After test-fitting those 2 pieces, I shipped them off to the ceramic coating company I used 2 years ago. The owner got the job done and the pipes shipped back fairly quickly. I had read that CoVid-19 can reside as an active virus on cardboard for up to 24 hours (and steel and plastic for up to 72 hours), so I set the box on the floor of my garage and let it sit for a few days. Once out of quarantine, they were ready to install.

Heat Shield

One of my biggest concerns about this whole project was how to keep the heat (up to 800*F) from cooking my legs on long drives. The MGB originally delivered with a heat deflector that was integrated into the floor, but mine was cut up as part of the floor replacement I did the summer after I got him. I looked into commercial heat shields, but they are awfully expensive and they are generic enough you need to trim them with snips, etc to get them to fit. Next, I looked into fabricating one with a few rectangular sheets of aluminum and a thin sheet of high-heat insulation. I constructed a fairly good model with cereal-box cardboard (one of my favorite modeling mediums), and was just about ready to take that leap when I found the HeatShield family of products. I decided that a known solution was a better choice than my experiment, especially when it came to temperatures that high. Their solution would cover 90% of the catalytic converter. This does not eliminate my concern about accidentally setting tall grass on fire if/when I parked on the side of the road or at a more rustic setting otherwise. Since the ride height of this sled is around 6 inches anyway, the honest truth is this car will not be going anywhere near tall grass. If I park off tarmac, it will still be where I can see the lifts and valleys of the ground.

Shield Assembly

cat hanging by one end

Once the heat shield kit had sat through a multiple-day quarantine, I unpacked everything and started putting things together. I wrapped the catalytic converter with the heat shield pad. These pads are a thick white fibrous material on the inside with a thick aluminum outer shell. At 10" by 12", it was just about the perfect size for the application. The catalytic converter is 11" long, so by wrapping the 12" side around the cat, I was left about a 1/2" of access to the ends of the cat for attaching to pipes. That orientation also left a gap about an inch wide running the length of the cat, which, based on the instructions, was about right. The heat needs to go somewhere, so a gap is needed (usually on the bottom) for the reflected heat to exit. The kit delivered with 3 stainless steel bands to hold the cover on. I installed one in the center to hold it in place while I installed into the car.

Into the Car

center resonator mated to cat

Once the cat heat shield was on enough for handling, I took the front pipe and fit it into the rear end of the header, checking the depth against the originally installed full-length pipe. Similar to the test fits, the cat easily slid over the rear end of that short pipe. I cinched down both pipe clamps, noting that the rear one did compress the edge of the cat around the pipe, and the cat was held firm (absolutely no wiggle). With the shield in place, the cat is now very close to the underside of the car. In fact, it may act as a vibration dampener, it is so close. I continued by adding the shorter pipe into the end of the cat. I did not clamp it down, however. Instead, I maneuvered the center resonator into place, sliding the front opening around the short pipe. I raised the tail pipe onto a short stand (an old car battery), and got the center mount aligned and bolted tight. With the center mount set, I could wiggle and twist the short pipe and the cat to exactly where I wanted them. Then, I clamped everything down snug.

Center Support

basic exhaust hanger added

I wanted an additional support for the exhaust. The Bell system does not have any mounts between the front of the headers where they bolt to the head and the support behind the center resonator. This is a long stretch of unsupported pipe already and one that I wasn't thrilled with when I installed it 2 years ago. Once you add a 5 pound catalytic converter, there is a real threat of the system sagging, and potentially failing, given enough time. So, directly behind the cat, I added a $4US exhaust hanger. This will take the weight of the catalytic converter plus any hang from the front of the center resonator. I tightened the hanger just enough to take up the weight and be snug, but not enough to pinch the pipe.

Finish Up
Once supported, I re-tightened all of the clamps and completed the attachment of the system at the tail pipe. Last, I returned to the heat shield around the catalytic converter, applying the other 2 stainless steel bands at the front and rear angled sections of the cat. Once snug, I snipped the ends of the bands. I hadn't expected it, but the final overall install is closer to the underside of the car than the no-cat header-back system was. I'm not sure what is really different, but the front of the center resonator is higher off the ground. Not complaining. Quite the contrary; just surprised when I expected the opposite.

Test Drive
I now have until the end of May to find a day that is both sunny and when Oregon DEQ is open. Because of CoVid-19, this might be more difficult than your typical late-spring in the soggy Pacific Northwest. That didn't stop me from grabbing Boo, dropping the top and taking a drive to bake-in the heat shield. April is what I call our "donut hole" month where we get nice clear days between the winter wet and the soggy spring. So, we got some gas (masks on!), picked up go food from our favorite Thai restaurant (Rama Thai) and drove home. Oliver drove like a champ. I think he's quieter with the cat than he was before I installed it. Of course, it has been a while. I have greatly missed driving the convertible around, having parked him since we discovered last Fall that there is a leak under the windshield on the passenger side when it rains. For a car living in the Pacific Northwest, where it kinda rains a lot, that's not a good situation. So, once this Summer turns to Fall and the CoVid-19 economic impacts have resolved, I know what I'll be doing on this car: pulling the dashboard and windshield to replace the seal. Knowing me, I'll probably want to do a bunch of other stuff while I'm there, like replace the scratched-up windshield glass and the dried out original surrounding rubber. Maybe I'll replace the foam/vinyl dash pad that's all cracked and gouged up. I don't know. Let's see where we're at when that time comes.

If you haven't talked to the elders in your world lately, consider they have lived a life of relative isolation in the US before CoVid-19. So, they could use a friendly phone call now more than ever. As always, thanks for following along. Be safe, be patient and please be kind--

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--