Ah, my slow search through my 1800ES's gremlins continues. My exhaust manifold is cracked. Maybe that explains some of the noises I've been hearing and smells I've been smelling? So far, it looks like a manifold in good condition is hard to find, and all the aftermarket replacements I've see are only for carbureted engines. Have any of you run into fixes for this sort of problem?

Waste of time and money welding it up. It cracked due to metal fatigue and will just crack again next to the weld.

Options:

1. $700 for a new one.
2. 2nd hand B20A, cut the intake off with angle grinder. Likely to last years because the B20A doesn't generate heat or get flogged.
3. Buy the smallest tubular 4-2-1 from Sweden. DO NOT buy the 4-1 like ipd sells, because it's junk and the less said the better about vpd the better.

One of the early episodes of Wheeler Dealers had them buy a custom manifold from a shop in California.

As I remember, it was not as expensive as I would have thought.

I will try to look it up.

Perhaps you can explain to me why a manifold for a carbonated engine won't work.

If access is a problem, perhaps steel headers would be relatively easy to modify.

James asked -- "why a manifold for a carbonated engine won't work." Maybe because of the bubbles? :-) You can cut the carbureted section of a combo intake/exhaust off and use the exhaust section. The flange thickness will be different so you can have the thicker one milled -- or -- I weld a 1/2 ring and full washer to make custom "stepped" washers. ALSO--need to add this--there's a locating pin set into the FI cylinder head -- I can't recall if that effects the intake or the exhaust. -- Dave

I'd go with cutting up a B20A manifold, it's a useless piece anyhow, no one would miss it. The pin for the FI exhaust needs to be pulled. They come out easy with Channel Locks and a big screwdriver.

Just because I was curious, I had to go searching. Skandix and others are now listing replacements for the manifold. Not cheap. Skandix lists it as their own brand. Pelican lists it as a Volvo OEM part; but, I expect not. I am suspicious about the Pelican listing because they call it an exhaust pipe and don't list Volvos older than 1976. I think that might be a re used part number or some other kind of error. The first two listings are legit as they are vintage Volvo vendors.

http://www.skandix.de/en/spare-parts/exhaust/manifold/manifold-exhaust-system/1068116/

http://www.volvoclassic.ch/webshop/gebrauchtteil-motor-419728-0-kollektor-auslass-gebraucht-d.aspx

https://www.pelicanparts.com/More_Info2/419728.htm

Now I am torn about what I should do with my Patriot header.

Been there with my 142 E. Mine was cracked roughly at the join between the 1 and 4 runners. I did the tour of the welding shops. The only ones keen to take it on were the shops that didn't give me any confidence as to their skills. The shops that had a reputation were reluctant because of the location of the crack and the usual hassle of dealing with cast iron. But, give it a try to see if you can find a skilled welder. Replacements are impossible to source and the performance of the Volvo 4 / 2 / 1 design is the best for anything other than an all out race car.

Replacement options for fuel injected engines consist of the Patriot Header which is sold by IPD and some others offered by European vendors. I have the Patriot on my B20E now. Fitment was less than perfect (the flange hit the intake manifold requiring a little grinding on the intake manifold to make it fit. The header tubes were seam welded and the seam on the #1 runner had split where it was squashed to fit in the flange requiring that it be repaired before it was even installed. You also have to deal with adapting the exhaust system to fit the header collector. If you are prepared to spend more money the European vendors make some nice stuff for Vintage Volvos (Tinus tuning and others); but, they come with a fairly heavy price even before shipping.

Knowing what I know now, I would be tempted to take the exhaust manifold to a fabricator and ask them if they can fabricate a replacement in stainless tubing. You would have to get the flanges fabricated; but, these days that isn't that difficult or expensive. With the original as a template you should be able to fabricate a jig to make an exact fit replacement. The cost will be higher than a Patriot header; but, better performing and probably cheaper than the cost of the European imports. If I hadn't thrown mine in the garbage that is what I would have done - knowing what I now know about the Patriot header.

If you decide to ditch your existing manifold and replace it with a header, post here or message me. I might be interested in acquiring your old manifold to take a crack at getting it duplicated in SS because I would really like to get rid of my Patriot header.

Drilling small stop holes, like 3/32 - 1/8" dia., at about 1/4" past the end of the "visible" crack may help arrest further crack propagation until you can find a qualified welder. In the mean time if you fill the crack and stop holes with exhaust joint paste you should be able to easily drill/grind it out later just prior to welding.
--
Current rides: 2005 Volvo S80 2.5T, 2003 Volvo V70 2.4NA, 1973 Volvo 1800ES (getting ever closer to road worthiness)

You need to find an experienced welder who has a "Dillon" gas torch, also known as a "Henrob". These torches were made primarily for welding thin material, but by changing tips you can weld & braze cast iron. A few years back Youtube had some videos showing how to repair cast-iron, and also welding aluminum beer cans together. They're amazing torches, and in the right hands can work miracles.

Depending on the severity of the crack they can be welded up. However, for long-term success, you need to find someone who is experienced in this problem and has done a lot of them. The correct rod for the welding, and proper preheating and cooling is needed. A shop that handles cars from the 20, 30, 40's established a long time is better than young Willy ( no discredit to Willy) down at the hot rod shop with a cheap stick welder.
Make sure you have the support bracket that goes from the bell housing to the downpipe fitted. That does reduce the vibration and leveraging that the rest of the exhaust system exerts on the manifold.