Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Exhaust Replacement - DIY question

Thank you for sharing the photos - lots to consider and they all look amazing, very motivating for me to get this done. I do have one additional question. My current exhaust system seems to have an air pump fitted that is connected to the exhaust pipe. Clearly an after-market change. I was curious as to the rationale - does it improve performance or reduce the heat of the exhaust pipe (or both). I'm always startled by how hot the parts of the car get that are in proximity to the exhaust pipe and was curious as to the reason for the pump and should I try to retain it.

I did not know that any Morgans had air pumps fitted as you describe but then I am no expert on Morgans... I did own an 80`s 911 which has an air pump and pipework connected to the cylinder heads just after the exhaust valve. I think the idea was to provide air in order to assist burning of fuel that had stopped burning in the combustion process due to the lack of air, and thus allowing it to burn up in the exhaust system, to clean up the eventual tail pipe emissions...?

Not something I have on mine - and we're only a couple of years out. Also, not something I've heard of before? I'd be interested to learn more. Where does the hot air go? I've had old cars with the movable air intake that can be used to gather warm air from the exhaust in winter, but nothing with a pump.

There's usually a large supply of cool air around the engine when moving - although obviously more temperate climate in the UK. However, did not have any issues when we had our really hot days last summer (over 38 degrees C) and I was using the Mog for the commute.

Wasn’t an air pump an emissions fiddle, just dilute the exhaust with air and it’s cleaner?
As your location is the “Bay Area” this could well be why you have the air pump.
What you need now for emissions rules I’ve no idea.
Cheers
John

That is a new one to me

John V6, here's an example, google for more info. https://www.restore-an-old-car.com/air-pump.html

Cheers

Thanks for the link - over complicated american smog emissions control thing! I would skip the pump - at the very least the pump will be sapping a bhp or two.

Seems every day has potential to be a school day....?

Are you speaking of making the header and exhaust yourself? The quick is answer is that making them IS a job, and assumes you know how to weld well. My old friend Bill Button, now passed, tried it for his homemade Plus 8, and after lots of back and forth, it worked!

If you are only speaking to merely installing a made-to-fit single manifold, it is not tough, just fiddly with a few common sense watchpoints. I can install a twin system in a morning, with a few tricks to help from being driven nuts (pun!). But I have done it often, my Morgans and many others. Everything is way longer the first time. The straight pipes, the silencer and (optional) exhaust tips easy to find. The least route hassle, though not necessarily the best solution (read on), is the most expensive method, especially for you in the US. Namely buying from the UK, with costly shipping. Additionally, the UK Morgan community does not use the most up-to-date world exhaust technology, though that is changing with all other marques, it has not done so as yet with the UK Morgans. On the other hand, the UK knows Morgans! In my case, I combine chose to go with the best of all worlds. Morgan branch manifolds with the standard flow-thru system in 2"

Here are the key points, IMHO.

1. Stainless steel has become dated as a goto for branch manifolds. There are technologically smarter methods for more than a generation.

2. Stainless steel and its welds are subject to embrittlement. Google it. Here is a start.
https://www.twi-global.com/technica...steel-welds-exposed-to-high-temperatures
https://www.sandia.gov/app/uploads/sites/158/2021/12/2101TechRef_304SS.pdf That being said, straight sections in stainless are very pretty (polished) and why not. They are far enough from the heat to not discolor and they can be had anywhere, opaque or polished. A traditional Morgan silencer (muffler) can be shipped or can be found in any shape or size in the USA.

3. The grade of stainless grades vary a lot, and very also within the Morgan community. One prominent supplier, not mentioned here yet, frequently has his stuff shear.

4. Stainless steel does not contain and focus heat any better than mild steel.

5. SS quickly changes colors, just as mild steel does, or anything chromed, with heat and usage unless you have VERY low bhp, (i.e. bicycle pedal power.. ). Nothing sadder than having a pretty bright and shiny header that soon turns purple or brown. Here is one ceramic option. https://images.squarespace-cdn.com/...eaders+-+classic+pollish.jpg?format=750w

6. I have a BIG distaste horror of exhaust wrappings. They make no sense, from any point of view.

For these reasons, the world moved on. 25+ years ago, Australia, the USA and Canada, began to whole-heartedly adopt ceramic coated headers. Ceramics have moved into so many things. In this case, the manifolds are coated and baked, inside and out, to almost any appearance the owner chooses. This process can be done at any time, as a rule. So if your current manifolds are in decent condition, (surface rust is irrelevant as they will be sandblasted) they can be thus treated, resulting in manifolds that focus heat IN THE PIPES, speeding its flow and helping bhp. If it is done with mild steel, the result is more flexible, impervious to age, much longer lasting without discoloration and the coated headers come out to the same price as new ss ones..The process will also work with stainless headers, new or used. BTW, one can also ceramic coat cast iron manifolds. https://www.google.com/search?client=firefox-b-d&q=ceramic+coating+manifolds

Being coated inside and out, the ceramic keeps the heat INSIDE the pipes and noticeably lowers your engine bay and cabin heat. 20 years ago, I could not find a single ceramic coater in the UK, now there are a score..though I haven't checked their prices. However it is very hard to find aftermarket mild steel exhausts, let alone manifolds in the UK anymore, same everywhere unless one finds a local fellow or make them yourself. There are DIY sellers in the US who will help you with the parts and methods used. Lots of help on YouTube.

Between the mild steel or use of your old manifolds, and the saving on the shipping, and the ceramic coating you can end up with a very enviable superior system at a very reasonable price.

But here is what should be close to your original stock system..according to our old friends at Harpers. You could design better. Look below.



Moss won't be any help. Morgan Spares will know where to find stuff and also have the headers coated.

WATCHPOINT Your exhaust system should always be suspended on rubber and should NEVER extend beyond the bumpers. If you hit an exhaust pipe at the rear, the impact can extend right to the manifold block bolts and damage the block.

Good luck.